Eagler's Nest

General Category => Builders logs => Topic started by: Pilotarix on July 07, 2021, 02:18:24 PM

Title: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 07, 2021, 02:18:24 PM
Hi all,

This might have the chance to become a thread about a Legal Eagle build in Pennsylvania. Likely not the first, I assume.

Anyhow, I have been close to starting a project before twice, If I recall this correctly. Around 2000 a Vans RV9 and 2016 a Zenith 750, both times life had different plans.
Now a new approach.
I got the plans as well as the supplemental wing plans from Iron design. 
I am about to source some of the wood. The cap strips for the ribs from Aircraft Spruce, and I am still waiting on feedback from my local lumber yard; they were convinced that they could source clear straight grain spruce. That was 2 days ago, and I have not heard anything, so it might not work out. The shipping cost for the plywood is insane, so I try local, but that is even less likely.

I will start with the wings. I have talked to John Bolding about a welded fuselage. I will very likely go this route to give the project a better chance to succeed. My welding skills are really subpar, probably worse, so I will improve them for the next fuselage, not for this one. 
My goal is not to monkey around, stick to the plans and get it done.
Certainly, the journey is an important part of the destination, but I will stay on paved roads.

Thanks,
Christoph

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 16, 2021, 04:57:45 AM
Hi all,

I ordered Sitka Spruce  and 0.8mm Plywood from Aircraft Spruce to start with the wing ribs.
I have the supplemental wing plans from Irondesign. Currently I am prepearing a straight board for the wing rip jig. I have worked many times on RC planes plans and covered the plans with two layers of the ususal kitchen foil. That was enough and worked fine but typically that is only to make one or two parts and not twenty-six. So I was looking for a clear slightly thicker plastic foil but I could not find something that really seem to fit. That stuff must be out there, I probably don't search the right way. Any suggestions on what to use?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Poorman2 on July 16, 2021, 05:25:00 AM
I went to my local print shop and had them laminate a clear plastic (possibly mylar) over my rib drawing.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 16, 2021, 05:52:45 AM
That is an excellent idea. I have a Staples close by and will see if they offer anything like that.
I have some clear vinyl, which is left over from making a Bimini top for our sailboat. It might be a little thick (almost 0.0125") and I am not sure if T88 will stick to vinyl, I guess I have to make a test.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on July 16, 2021, 10:34:07 AM
I used two layers of clear self-adhesive shelf paper from the grocery store. Worked great.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 16, 2021, 11:58:51 AM
Great Idea with the shelf contact paper.
I also like that idea with the clothespins. That will avoid staples and the work to get them out later. Also nice the excenter wedges to keep the pieces in place, I assume they make it easier to get the glued rib off the jig. 
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on July 16, 2021, 01:27:01 PM
I just varnished the plans and put a couple of coats of paste wax on everything.
If you haven't seen it, I have pretty much documented the build in "a little progress XL-58."
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on July 18, 2021, 01:31:14 PM
Christoph, I'm building a Legal Eagle XL in Waynesboro, VA just down I81.  If you want to talk XL's give me a call.  DA Miller 540-480-0315
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 18, 2021, 03:44:12 PM
I just varnished the plans and put a couple of coats of paste wax on everything.
If you haven't seen it, I have pretty much documented the build in "a little progress XL-58."

I saw your thread, excellent I like it. Many good pictures that help a newbie builder like me connect the plans with reality, which I think is sometimes not easy.

I got my wing plan laminated at a Staples store. Looks pretty good, clear, has no wrinkles, and the lamination will withstand a beating. I still have some 1/4" Delrin plate from another project that I can use to realize a clamping mechanism. I also have an adhesive-backed thin neoprene rubber sheet that will definitely not stick to the epoxy that I could use on plywood for the clamping mechanism.
I want to do both gussets at the same time if possible. I think I read that some people have done that.
 
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 18, 2021, 03:57:14 PM
Christoph, I'm building a Legal Eagle XL in Waynesboro, VA just down I81.  If you want to talk XL's give me a call.  DA Miller 540-480-0315

That sounds like a very good idea. Currently, I am still a little bit confused by so much information. I hope to get my jig finished next week. My wood for the ribs should arrive tomorrow.
How far are you in to your project?

I did send you a pm with my email and phone number.
Thanks
Christoph
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on July 20, 2021, 11:21:54 AM
Quote
Many good pictures that help a newbie builder like me connect the plans with reality, which I think is sometimes not easy.

That was the idea.  :) I hope it helps. I've been an EAA tech counselor since the 80s. One of "my guys" has a Lindy on his mantle, and said.. "I just couldn't wrap my head around those plans."  :grin: So, you are not alone. Keep studying and it will (mostly) become clear.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 21, 2021, 11:26:17 AM
That was the idea.  :) I hope it helps. ...

It definitely helps, thank you. A picture is worth a thousand words.


Not much is happening here.

I got the order from my "administration" to finish the School Desk Project for our son before doing anything else. I think I have to comply with that to keep everybody happy :D



My plywood arrived yesterday evening. The box definitely took a beating during transport.  Unfortunately, all of the three plywood sheets have slight damage on one side and a corner. 
No cap strips yet. They were marked as in-stock when I ordered them, and the order is now for 5 days on "preparing for shipment."  I called Aircraft Spruce today and asked how things going, and they told me that they are still cutting them, so no definite delivery date yet. Not a problem, now I can start with cutting gussets, enough to do.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 21, 2021, 03:29:41 PM
I just saw the email from Aircraft Spruce. Cap strips to be shipped within a “couple of weeks”. I am on position 9 or 10. Oh well, enough time for the school desk and the gussets I guess.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: CHARLES DEBOER on July 21, 2021, 09:31:51 PM
Some of our members have requested that their plywood be rolled and shipped in a tube.  Don't know if ACS still provides this service but it might be worth asking for future purchases.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 22, 2021, 07:38:44 PM
Some of our members have requested that their plywood be rolled and shipped in a tube.  Don't know if ACS still provides this service but it might be worth asking for future purchases.

Thanks, I will try that the next time.

It looks like I have to start the built from the tail end.

The wood will need a couple of weeks and whether or not I am going to build the fuselage myself is still undecided. Recently a couple of people encouraged me to try, so I am on the fence with that.
The other big piece to attack is on the tail end of the plane, the stabilizer, and the rudder. So I will start there.
A while ago, I was told by people who should know better that there is no metal supply store in our area. So I went online and checked prices. Online metal offered all aluminum tubing for about 450$ plus 390$ shipping. Crazy. I canceled that and went on to the lumber yard to order two 14' I-joists for the table. The lumber yard is an area where I normally don't go to. On my way, I came across a small sign pointing towards a company High Tech Metal. It did not look like a lot from the road, but in the back of their compound, there was a warehouse, and they had a pretty good amount of different metal pieces on their shelves. I pulled up the material list on my phone, and the guy was not impressed. I have all of that, was his response. So he gave me a quote of about 350$ for the aluminum tubing, 100 less than online, and obviously no shipping. They have all the different 4130 tubings as well.
So tomorrow, I will get the aluminum tubing and a quote on the 4130 tubings.

One quick question, I assume the the SQ on the 4130 material list stands for square - meaning square tubing?

Title: Re: Legal Eagle XL in Pennsylvania
Post by: CHARLES DEBOER on July 22, 2021, 10:06:35 PM
You are correct on the SQ for the tubing. Square Tubing.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Poorman2 on July 23, 2021, 12:02:48 PM
Make sure the 4130 is not made in China. USA or German made!
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on July 23, 2021, 06:21:24 PM
C, you might considering going through the prints and identifying where each tubing is used and verifying the dimension of each.  This will really help you get knowledgeable on your XL project.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 24, 2021, 04:47:39 AM
@Poorman2

This company has "American-made" all over the place. I bet they would get a bad rash when they touch steel from China. But seriously, is there a way to find out for sure where the stuff is coming from? The 4130 tubings that I got from MacMaster for some welding training were labeled with 4130 and some other numbers but not the country of origin.

@Da
I will definitely do that. After talking to you and trying to make a plan for the tubing layout, I realized that I have to go through the plans a couple of times to make sure I really understand what is on there. 

Yesterday afternoon I got the aluminum tubing, actually not all of them. Other than promised, they did not have all of them. Supposedly it will not take them long to get the rest. We will see.

The saga continues by making two simple but sturdy sawhorses for the table.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 25, 2021, 10:17:51 AM
Hi all,

I got an email from UPS and it appears that Aircraft Spruce shipped the cap strips. Not sure what happens and why this happens so fast now. I just take it.
For some time now I think about how to cut the plywood gussets efficiently and consistent and accurate. From what I have seen many seem to use a paper cutter, some sissors and others had access to a laser cutter.  Making the gussets seem to be a tedious repetitive task. A laser cutter apears to be a good solution, but setup and preparing the files can be time consuming as well.
For now the paper cutter is my favored solution. I assume that there is some kind of way to do it efficient, with minimal waste?
Any thoughts?

Thank you,
Christoph
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on July 25, 2021, 06:44:17 PM
C, do a search on "gussets" and you will find many good ideas on organization and process/
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 25, 2021, 07:23:03 PM
C, do a search on "gussets" and you will find many good ideas on organization and process/

I did; maybe I have not seen the good stuff yet. I will search some more.

I made a drawing from the vertical stabilizer and rudder. That helps me to get familiar with the plans and will serve as a template when I make and layout the pieces on the bench. The gussets are not final.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on July 26, 2021, 12:04:43 PM
I was thinking of rib gussets.  Some builders with bigger engines(45 hp) made the leading edge of the vert stab of 4130 and rid stitched the vert stab. Most used paper patterns when making the Al gussets.  Most wrapped the gusset around the tube rather than a gusset on top and one below. Three rivets per rib seems to be popular. Make the "U" shaped ribs edges that receive the rivets bigger than 1/4 inch.  Cope the ends of the ribs to match the round tube.  This doesn't have to be perfect. Don't forget,  do the short bottom bend of the stab leading edge first.  Don't worry if the bend is not exactly even with the bottom rib.  There's probably another 50 hints but I can't think of them now. Keep at it!
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on July 26, 2021, 12:08:47 PM
Look at Chuck in Indiana's build log p13.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: jrbirdman47 on July 27, 2021, 04:23:33 AM
I made the gussets of cardboard first, to prove they were right, then duplicated in aluminum. I also found that if I bent the gussets around the next smaller sized tube that it would "spring back' to fit the correct size tube perfectly. Lots of little hints like that buried in the archives.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 27, 2021, 06:16:08 PM
I was thinking of rib gussets.  Some builders with bigger engines(45 hp) made the leading edge of the vert stab of 4130 and rid stitched the vert stab. ...
Don't forget,  do the short bottom bend of the stab leading edge first. ...

@DA
I may go with a 2 stroke engine. Hirth 23, which comes with 50 hp, but not sure yet. What is the reason for using 4130 on the leading edge of the ver stab with bigger engines?
I am not going to forget any of that. I made a note in the plans.

@jrbirdman47

Carboard is my plan as well. The plans I drew are really only for laying out the tubing and to get a rough idea about the length of the ribs and the gussets.

I picked up the I-joists from the lumber yard today. When the guy came with the forklift, I thought they would never fit in the Sprinter, but they did. Another time I could avoid the delivery cost.  :)


(https://www.eaglersnest.com/forum/index.php?action-post;quote=13844;topic=2400.15#:~:text=Choose%20File-,sprinter,--1)


The aluminum sheet from Online Metals arrived. UPS just threw it on the front porch in the half-hour nobody was home. Seeing the package, I knew that there would be and issues. With lots of dents and ripped open, the content was bent. If I had been home at the time of delivery, I would have refused the delivery. Not sure what to do with that. I hope the cap strips will be in better shape.

(https://www.eaglersnest.com/forum/index.php?action-post;quote=13844;topic=2400.15#:~:text=ups-,-,-1)

(https://www.eaglersnest.com/forum/index.php?action-post;quote=13844;topic=2400.15#:~:text=ups-,-,-1)

I started making two very basic sawhorses, but some house inhabitants felt annoyed by the noise::). This Dewalt Miter saw is really loud, so I had to postpone the work until tomorrow.

(https://www.eaglersnest.com/forum/index.php?action-post;quote=13844;topic=2400.15#:~:text=Choose%20File-,sawhorse,--1)

The plan is to build the entire plane in the basement, stable temperatures year-round, and all my tools nearby. Here is where the table will go. I need to make a little more room and rearrange my scrap wood.


(https://www.eaglersnest.com/forum/index.php?action-post;quote=13844;topic=2400.15#:~:text=Choose%20File-,table,--1)




Title: Re: Legal Eagle XL in Pennsylvania
Post by: Tom XL-7 on July 27, 2021, 06:30:19 PM
when you receive damaged goods contact the seller. do not throw the box away and be ready to photograph everything.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on July 27, 2021, 06:53:22 PM
C, I'm not sure about the 4130 on the leading edge of the vert stab. Perhaps it's because of more airflow or more turbulant air flow. Maybe someone with a 50 HP engine and 4130 leading edge will chime in and enlighten us.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 28, 2021, 07:34:39 PM
@Tom XL7
I called Online metals, they asked me to send pictures which I did, and only an hour later, they send me an email saying that they will send me new Aluminium sheets at no cost. Not too bad. I hope they will pack them better, and UPS will be a little bit more careful.

@Da
It would be really interesting to know. I hope that somebody who did that could chime in here.

To the rivets. I will probably use Cherry max aluminum rivets of the appropriate size. They are pretty strong and safely retaining their shank. This will eliminate the whole ordeal with painting rivets and the like. Also, if I am not mistaken, it is not recommended to mix stainless with Aluminum not only because of the potential for galvanic corrosion. Anyhow, on the other hand, this is not going to be a Space Shuttle...

My shop apprentice helped me today to finish the sawhorses. Probably the fastest and easiest to build sawhorses. The whole thing is already pretty level, and I hope that I can get the plywood tomorrow.

In the evening, the package arrived from Aircraft Spruce. About 100 1/4 X 1/4" cap strips. After opening, I realized that the cap strips were not exactly 1/4 x 1/4 or .25 X .25. They were more .22 (.23) X .25. That is clearly not what is on the order... is that normal?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: jrbirdman47 on July 29, 2021, 07:46:30 AM
My cap strips were the same, nothing exact, and as you say, it's not the shuttle. Almost all had one side that was pretty darn close to .25"
However.......Be careful to place the strips in the jig oriented so that the 1/4" dimension is toward the "most correct" side. (Think about it, you'll see what I mean)
I also found that because of this slight dimensional deviance I had to apply layers of masking tape to press the  1/4"parts firmly into the inward jig blocks in the rear spar area so that the correct dimension would result. (the outside doesn't matter, but the inside is where you'll be glueing it to the rear spar, so it needs to be correct. Just remember those slight dimensional differences as you go along and you can "fix" any potential issues. And.....it's not the space shuttle  :grin:
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on July 30, 2021, 07:13:15 PM
...Be careful to place the strips in the jig oriented so that the 1/4" dimension is toward the "most correct" side. ...

Thanks for your input. I think I understand what you mean. I assume that this is one reason that some use cam clamps rather than a jig with fixed dimensions in all directions. With cam clamps, one can account for varying dimensions of the cap strips as long as the correct dimensions in critical areas are being accomplished.


Today I wasted most of the time hunting for plywood sheets for the table. Prices are still insane, and in the big box stores, they had no staff to handle their panel saw.  ::) I don't have a circular saw, so I cannot really handle full panels very well. I had to go to my hardwood dealer not to waste more time, which did not improve the price range.
On a positive note, the replacement from Online Metals already arrived,  this time with no damage.

With the plywood cut to the correct width, I could almost finish the table. Then my "administration" reminded me that other things would require attention as well.
To finish the day, I put the Piper skeleton on the table that helps imagination, and it looks pretty good there. Unfortunately, it's only  1:16 ...
The stupid lawn then killed the rest of the day...
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 07, 2021, 06:20:37 PM
Back from a short vacation, and as Jon Croke always says at the end of his videos, "everyone back to building."

I am trying to figure out what rivets sizes the designer suggested for the tail surfaces. In the description he mentions, stainless steel rivets but no size; at least, I cannot find the size. I read somewhere about 1/8" stainless steel rivets, but I cannot find this in the plans. I must be blind  ::) . I appreciate it if somebody could give me a little hint on how to find this information.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on August 08, 2021, 05:45:29 AM
I'm back from vacations, too. Oshkosh (no legal eagles) and the Wisconsin Moto Guzzi rally.
1/8" rivets.. I don't remember  ::) how I know other than that is what is called out on the materials list. Like much stuff on the materials list, though, there won't be enough.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 08, 2021, 11:06:32 AM
I used Marson stainless rivets with stainless mandrel. The SSB4-1S rivets worked for almost everything. I did use some SSB4-2S rivets in a few places.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 08, 2021, 08:09:45 PM
Hi,

Thank you for your input!

I'm back from vacations, too. Oshkosh (no legal eagles) and the Wisconsin Moto Guzzi rally.
1/8" rivets.. I don't remember  ::) how I know other than that is what is called out on the materials list. Like much stuff on the materials list, though, there won't be enough.

Excellent choice. I have never been to Oshkosh, tried many times, but there was always something else, and the rest of the family is not so enthusiastic that they would spend family vacation time in Oshkosh. The Moto Guzzi Rallye sounds pretty interesting as well.

I used Marson stainless rivets with stainless mandrel. The SSB4-1S rivets worked for almost everything. I did use some SSB4-2S rivets in a few places.


I read about Marson rivets in other places. It sounds like 1/8" stainless steel rivets are the way to go despite the material mix - stainless/aluminum - which is usually not recommended (galvanic corrosion) but seems to be pretty common. Hence it can't be that bad.

I spend the day working on the wing rib jig. I monkeyed around with the CNC router to make some little cam clamps. That was working well, so I continued with some blocks of different sizes. I included screw holes, but I did not use screws since the blocks always slipped out of position as I tighten the screw, no matter how careful I was. A downside of the lamination, that stuff is pretty slick. I ended up using a thin double-sided tape and a pneumatic nailer.
As you can see, the jig is not completely done. I have to make smaller cam clamps, and I have not yet decided how to clamp down the gussets until the glue is dry.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 09, 2021, 08:57:52 AM
Here is a neat video by Les Homan. He built 3 Legal Eagles. https://www.youtube.com/watch?v=YuXwGg_9czY
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 10, 2021, 07:34:22 AM
Here is a neat video by Les Homan. He built 3 Legal Eagles. ...

Thanks for this link!

I think I saw that video a while ago. I watched it again, and this time I paid more attention to the details.
He seems to be pretty quick making these ribs. It looks like he has developed a good system and some practice.
There are a couple of things I am not so sure I would do them the same. He is using Tidebond III exterior wood glue. Nothing wrong with that specific glue. I have used Gallons of that in all sorts of woodworking projects, great stuff. However, this glue is not really good at gap filling, and there are gaps if not every piece of cap strip was fitted precisely. Also, wood glue needs even and good clamping pressure. He may have that on one side but not with the clothespins on the other side.
The clothespins are good for epoxy joints because high clamping pressure is not so critical with Epoxy. Actually, too much clamping pressure is not good for Epoxy joints since you don't want to squeeze all the glue out of the glue joint.
Anyhow, I might be too picky here, and we already mentioned that we are not building a space glider or the like. But, at some point, my "behind" is going to hang on these wings. So being a little bit picky is probably warranted.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 10, 2021, 09:25:19 AM
I used T-88 for its strength and gap filling properties. All my test joints broke wood, not the glue line. Used cut back clothes pins for pressure.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 12, 2021, 08:00:15 PM
I used T-88 for its strength and gap filling properties. All my test joints broke wood, not the glue line. Used cut back clothes pins for pressure.

The clothespins are a great idea, and their clamping pressure is likely sufficient for an epoxy glue joint. As already said above, you don't want to squeeze all the glue out of the joint. I will probably borrow the clothespins idea.

In the last two days, I made a little bit of progress with all the prep work.

I had not had a good idea how to cut all the gussets, and all the suggestions out there are great but still not what I was looking for. I had laser cutting in mind and made some DXF files for the gussets using the dimensions given in the Iron Design wing plans. Easy task, did not take too long.
Then I got the diode laser out. What can I tell you? It was an entire failure.  It could cut the thin plywood in one pass, but the result was not pretty. Not at all, and it took quite a while for a little part. In the end, I was not too impressed by the burned edges and decided not to use the laser for cutting. A  CO2 laser would have been way different... but I don't have one of those.
Anyhow, I used the laser to make patterns of the gussets on the plywood, which worked, at least in my mind, pretty well and fast.
After making all the gussets, I cut all the cap strips on the table saw—nothing exciting here. Some minor tweaks on the jig, and I can start making ribs.

Like many, I did a gluing test as well. I used T88, and the result was not really what I expected. The glue joint did not fail, but the gusset came of the cap strip quite easily. I was not really impressed by that. It looks like the glue did not really penetrate the wood. Just the top layer and there, the whole thing separated under stress.

Today I did another test with T88. This time with a little bit more glue and I paid very close attention to get the mixing correct.

I also made a test joint with WestSystem Epoxy. One without and one with adhesive filler. We will see tomorrow how that turned out.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 12, 2021, 08:45:14 PM
Looking good! Those glue joints look very nice. I stacked 28 small sheets of 0.8mm ply locked with toothpicks and glued the Iron Design drawing on top. Cut several hundred gussets at one time with bandsaw.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 13, 2021, 08:46:48 PM
Looking good! Those glue joints look very nice. I stacked 28 small sheets of 0.8mm ply locked with toothpicks and glued the Iron Design drawing on top. Cut several hundred gussets at one time with bandsaw.

That is excellent; looks very efficient. I had the bandsaw in mind but wasn't sure if I could keep the pieces aligned while cutting. I should have tried.

I tweaked the jig a little bit. In the Iron Design wing plans, it is suggested to make the space for the rear spar slightly bigger, only 0.032", which should make it easier to fit the spar. Initially, I did not do that, but after I have seen a video where the issues fitting the rear spar were mentioned, I decided to increase the width of the rear spar spacer by the above 0.032".

I abandoned the idea of using clothespins after finding a pack of toggle clamps that I had bought a while ago for another project. I had thought about them earlier but also thought that they were way too big. But actually, looking at them, they weren't that big at all. So I gave it a try. They are mounted with only one screw. That is enough. It doesn't need much clamping pressure with epoxy, and I can rotate them out of the way.
With all of that done, I decided to go for a first glue-up.
Finally, I have chosen T88 over WestSystem, and the reason is mainly pot life. WestSystem is about 20 min, depending on temperature and the like. T88 pot life is about 40 min. Plenty of time to screw stuff up and correct it and still be able to finish a glue-up.

I go with little plastic cups and a one-way brush. If I use epoxy, I always keep the rest until the next day to see if the glue has been set appropriately. When problems arise with the glue joint, I know if it was the epoxy or not.
I used this little scale for mixing, which takes away the guesswork, and I can always make the same amount. This first time I mixed way too much glue, but now I have a pretty good idea of how much I need and can do better next time.

I hope I get this thing in one piece out of that jig tomorrow; we will see.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 13, 2021, 09:10:11 PM
Toggle clamps look great and your woodwork is very nice. I would have used toggles if I had more on hand, but the clothespins worked fine for me. Most of my ribs took between 35 & 45 minutes to glue up (all parts). Never had a problem with T-88 open time. Even did some tests waiting an hour before gluing and the joints never failed at the glue line.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 15, 2021, 07:17:25 AM
Toggle clamps look great and your woodwork is very nice. I would have used toggles if I had more on hand, but the clothespins worked fine for me. Most of my ribs took between 35 & 45 minutes to glue up (all parts). ...




Thanks!

In all the discussion about different Epoxy glues, the long pot life and the viscosity really stick out positively with T88. WestSystem, as much as I like it, is pretty runny without thickening and unthickened better used for surface coverage than gluing.

I found an advantage of clothespins over toggle clamps. These toggle clamps, when closing them, pull the workpiece inwards and out of position. The whole thing is worsened due to the workpiece gliding on the glue, not really a problem, just something to be aware of so it can be corrected.

I need about 55 min for a glue-up. I wet out the entire surface of the gussets with epoxy. That may give a little extra strength to the gusset, and I don't need to worry about wood protection in these areas when it comes to varnishing later in the process.   

I still use too much glue, so I have some squeeze-out. I mix 12g for the glue-up and still have some left in the pot at the end. The squeeze-out is, unfortunately, in areas that I can't reach very well after clamping. This will cause some sanding later.

I keep the rib for about 12h in the jig. This will allow me to make 2 ribs a day, one in the early morning the other one late at night. One rib has about 73g.

I am about to order the rest of the wood at ACS. However, I still think about alternatives, like the Doug Fir I have in my garage. Just for the spar caps. Last night I read a lot of information on aircraft wood, usable species, availability, grading, and so on. It sounds like we have to look for alternatives to Sitka Spruce and ! Doug Fir soon. 

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 15, 2021, 08:57:24 AM
Hi all,
I am about to start the vertical stabilizer and rudder.
The rudder fin plan calls for a 5" radius on the upper bend but I cannot find the specification for the lower bend radius. I compared this to the elevator, the radius looks pretty similar, and there, the radius is given in the plans, 6". So I choose a 6" radius. Now I have seen that some have used a 3" radius in that location. Is this information in the plans and I just miss this? Is the radius critical here?

Thanks
Christoph
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 15, 2021, 09:44:39 AM
As I remember, I used the same 6" radius block to bend both angles, just did not bend the bottom angle as far. My finished rudder was pretty close to the plans but a little smaller area. Attached are photos of my rudder and two others showing those builders decided to use their own shape. Here is your chance to be creative!
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 15, 2021, 12:57:00 PM
Hi,

Thank you for your answer.
That is quite a variation.
And yes, I thought that the dimension would not be very critical, but there is a lot I don't know, so I'd rather ask.

Now I can continue with what I have already started.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 15, 2021, 01:04:20 PM
I like your bending forms. Don't know if you bent aluminum tubing before, but you will probably have to move your forms toward each other after your first bends because of springback. I moved my forms a couple of times until the final bends looked OK. Here is a little video of bending tailfeathers.  https://www.youtube.com/watch?v=Wwa4YQD0AL4&t=267s  Also look on YouTube for flyguyeddy. He has several videos about the tail.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 17, 2021, 02:48:45 AM
Thanks for the link to the video. All good information.

I have not bent aluminum tubing before but a lot of wood. Certainly, that is not the same, but there is spring back as well. I never accounted for it since the wood could be bent to the desired shape during the final installation without introducing too much stress.
It sounds that this is different here. We don't want to introduce stress into the piece by just forcing the tubing ends into the correct location during the final installation.
I have changed my bending blocks a little, so far only on paper. This new shape would allow me to bent the tubing further than necessary to account for spring back.
Not sure if that would work, but I will give it a try.  The lower bending block has to be installed first, and after making that bend is made, the upper bending block can be installed.

I have made some progress with the ribs. Unfortunately, the last one got stuck in the jig and was damaged. Some have used wax or the like to avoid these problems, is there anything specific suited well without interfering with gluing?

Title: Re: Legal Eagle XL in Pennsylvania
Post by: 914pete on August 17, 2021, 11:44:37 AM
Costco sells a Parchment paper that I've been using and have yet to find anything that sticks to it. Even when epoxying the ribs to the spars rather then cover my whole work table I just cut 5"x5" squares and slid them under each joint I was gluing to catch any runs avoiding gluing the ribs/spars to the work table. After drying the glue drips just fall off the paper so it can be re-used over and over. Its transparent enough that I used it to cover my rib jig right over the rib drawing. Like $9 for two huge rolls.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 18, 2021, 07:40:45 AM
My plan is laminated and this stuff seemed to be pretty slick. Epoxy is not really sticking to it. I have no wooden positioning blocks in glue areas as well, but some small plastic blocks to keep the gussets in place. In hindsight, that was not the smartest idea and I removed almost all of them. It works fine without them. I only kept the Delrin blocks, one is the spacer for the rear spar. Nothing sticks to them. Now it works much better. Just got #6 out of the jig this morning.

No need to speed up the rib production too much because I don't have the wood for the spars.
First, I am undecided in what lengths I should order. The long spar caps are 154" and 12 foot is the maximum length that can be ordered, so I will have at least one scarf joint per spar cap.

Now the question becomes if I should order in 6 foot - 3 pieces per spar cap and two scarf joints oder in 8 foot and 6 foot - 2 pieces per spar cap and one scarf joint.
The advantage of the 6 foot pieces is that they might be easier to get.
The advantage of the 8 and 6 foot pieces is that there is only one scarf joint towards the end.
Thoughts?

Second, I am considering using Okumee plywood. Marine grade, Lloyds certified 1088. It's light and strong but not as rot resistant as Birch plywood. I has been used extensively in aircraft production. It's expensive but I can get this locally and there is not transport cost. Transport cost are astronomic for plywood sheets.
I am considering building a main spar with Doug Fir (quater or rift sawn and clear straight grain) and slightly reduced thickness of the spar caps and 6 mm Okumee plywood. And break it... meaning, test how much load it can withstand.

Not sure yet.   

I have been on the phone with aircraft spruce, they told me that they don't get the amount of wood that they normaly getting and delivery time is dependend on what I order. Long pieces (6 and longer) take longer to source. Up to 4 months, maybe longer.
I could finish the rib production make them nice and shiny and then work on the tail. If that is done and the wood has not arrived I could start on the fuselage. But that opens a whole nother can of worms due to my (none exsisting) welding capabilities.  ::)
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 18, 2021, 11:28:08 AM
If you go with spruce for the spar caps, I suggest the 3-piece spar cap with two splices (one nearer the tip). A proper splice is as strong as one piece when you put a small ply web over the splice side opposite the main web. Just remember the splices will take almost a foot from each piece you order (overlap), so don't order too short.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 19, 2021, 05:00:39 AM
… Just remember the splices will take almost a foot from each piece you order (overlap), so don't order too short.

Thanks! I was aware that a scarf joint needs some “space” but I was not really calculating with almost a foot, not sure why…  ::) I will go with 6’. That gives me 18’ with a good amount of room for the scarf joints and screw ups.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 22, 2021, 05:18:29 AM
Hi all,

Here is the progress since my last post.

Yesterday I made, what is called in the IronDesign plans the K-Block Cover Gusset. Twenty of those are needed, and there is enough information in the plans to transition them quickly into a CAD system. So I did that and then let the laser do the work.

(https://www.eaglersnest.com/forum/index.php?action=dlattach;ts=1629634707;topic=2400.0;attach=5382;image)

I did 12 wing ribs so far. One a day and on weekend days 2 a day. I thought that I could do 2 every day, but that did not work out.

I am making each wing rib for its dedicated position in the wing. I made the first compression rib for the right-wing and cut the gussets accordingly.


I added some clothespins to the end of the jig to hold down the gussets while the glue dries like described by Kamcoman77. For the very small gussets, they work better than the toggle clamps, and their clamping pressure is enough if T88 glue is used.

We currently see heavy rain that is likely given to us by "Henri" and as bad as it might be it's also a perfect excuse to spend a big part of the day in the shop. :))

BTW... is there a way to put pictures into the text instead of having them all at the end?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 22, 2021, 03:41:58 PM
Thanks!

My plan was not to cut the K-Blocks with the laser. For the thin plywood, the laser is OK, but for the 1/4" plywood, it becomes a pain in the behind and a lot of smoke. This is only a toy laser with 15 or so watts. Anyhow, since I could not start bending tubes for an embarrassing reason::)  ... I cannot get the sand in the 5/8 tubing ... I made the CAD drawing for the K-Block. That was a little challenging since there were only two measurements, and the rest has almost an organic shape. Then I made a test cut on the laser, 1/4" Birch plywood, not too bad.  I assume that I will make the actual parts on the CNC router.
For the picture, I put the K-block gusset and the K-block on a finished rib just to see if and how it fits.

Also, I may have found another source for aircraft plywood and spruce, but I have to confirm that tomorrow.

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 22, 2021, 04:58:46 PM
Very nice looking K-block. I cut mine on a bandsaw and they are not nearly as true to shape as yours. I did not put sand in my tubing. I used those cheap, spring type tube protectors to keep the tubing from flattening in the curves. Worked great.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 23, 2021, 11:29:55 AM
... I did not put sand in my tubing. I used those cheap, spring type tube protectors to keep the tubing from flattening in the curves. ...

I am not sure what exactly brought me to the "sand in the tube" method. I think I did this before with thin stainless steel tubing. Even though I used very dry and fine aquarium sand, the tube clogged up immediately. Anyhow, I have already abandoned this method and ordered the doohickeys you and others have used.

Meanwhile, I continue with my wing rib business. I have made eight "normal" and three "right side compression ribs" so far.  One more than I have to change the setup for the "left side" compression ribs. Four compression ribs on either side if I interpret the plans correctly.

Today I had some spare time and put more of the pieces from the plans into the CAD. This time the nose rib.
With the nose rib, I cut a K-Block on the CNC. The plus of the laser is that you don't have to do any fixation for the pieces to cut. The big downside is you have to sand all the glue faces; otherwise, you may get into severe trouble later.

One big question, I see that you have used - like others - 4130 steel tubing for the leading edge of the vertical stabilizer. The plans don't call for that. At least I have not seen that. Is there a specific reason other than more stability?





Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 23, 2021, 11:54:22 AM
Very nice work! The 4130 leading v-stab edge was recommended by several experienced LE builders/flyers. They said the 6061-T6 LE showed some fluttering/vibrating, but the 4130 is rock solid.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 25, 2021, 11:27:42 AM
Very nice work! The 4130 leading v-stab edge was recommended by several experienced LE builders/flyers. ...

Thanks, fluttering is definitely not what you want. So I will go with 4130 for the leading edge of the vertical stabilizer as well.

So far, I could manage to make at least one wing rib a day. We will see if I can continue at this pace.
Today I made the first compression wing rib for the left-wing. According to the plan, the 1/4x3/4 wood strips are only glued to one side, the side facing the wing root. That seems to be not so clear in the Iron Design drawings. There it appears that they are on both sides. Anyhow, I will follow the original plans.


I also made the Aileron Stiffener. It took me a while to figure out the shape, only because I didn't realize that one side is not a straight line; it's following the wing profile.  ::)
The "test piece" is done, and the shape is confirmed on the wing rib and the plan. I still don't have the aircraft-grade birch plywood, so I can't make all the pieces, only test pieces.   :(

Finally, a picture of my glue cup collection. Always when I work with Epoxy, I keep the residual glue at least until the next day to see if it hardens correctly. I realized that if I try to break off the stir stick, the hardened glue puddle breaks before the stir stick. That never happened with thickened WestSystem Epoxy. There, always the stir stick breaks. I checked my mixing ratio, but that is correct, and it is the same in two different batches of glue. Maybe that is just the way it is and today for the first time the stir stick broke before the glue puddle.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 25, 2021, 05:44:25 PM
Yes, that is exactly what I am using. 10 and 8.3 and there is always a little bit leftover in the cup. It hardens as expected  and I made another test where I broke a joint with cap strips and gussets, the wood seperates but not the glue joint so I think it should be OK.

Tonight the bending doohickey showed up on the front porch and if I don’t have to work all night I may do some tube bending tomorrow.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 26, 2021, 04:54:13 PM
Nothing new today. Had to work the entire night so wasn't even able to make a wing rib today.

I am still in limbo with ordering the rest of the wood. I thought about other wood types, like Okumee for the spar web and Doug Fir for the spars but that would really involve testing and will take too much time. My goal is still not to monkey around too much, get it done and in the air. Hence I am going with Sitka Spruce and Birch plywood.  The latter, aircraft grade Birch Plywood is not easy to get. All my local suppliers failed on that one and currently it seems that I have to order from Aircraft Spruce and pay the crazy transport cost. However, the transport cost are not the only caveat. I realized that Aircraft spruce only offers 4x4' Birch-Plywood which means that I have to do 2 scarf joints to make the entire length of the spar web.

Is that what most of you have done?
Or ... were you able to get plywood in 4X8' sheets? Is there Birch in 4X8' ? I have not seen that, only 5X5' at best.

I think I have seen pictures where the spar web did not look like it was Birch Plywood and they seem to have only two scarf joints. Could that have been Mahogany Plywood Mil-P-6070?  That is available in 4X8'.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on August 27, 2021, 11:21:43 AM
I'm back from another trip and a fly in.. yeah, I've been slackin.'  :)
I made all the plywood parts with a toy router that I bought just for this project. Made router templates on the cnc, and whizzed them right out.
I also used it on the scarf joint.
(https://static.imgzeit.com/large/63610420b35efbc5/IMG_20200502_132727669.jpg)
test piece to check scarfs and the hole thingy..(technical term)
(https://static.imgzeit.com/large/f22986f4d6942c54/IMG_20200715_164249200.jpg)

Nice work, attaboy! Keep it up..
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 27, 2021, 01:14:45 PM
Looking good! What kind of plywood is that?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 27, 2021, 06:21:52 PM

Somehow I am missing the reply from Kamcomann, I saw it earlier, and now it seems to be gone, mysterious...

Certainly both great solutions, thanks for showing.
For boat building, I used a hand plane to make scarf joints. I think I am going to step up and use a machine this time. I have both machines, a small router, and a hand-held band sander, not sure what route I am going.

I will use Birch plywood from ACS even though the shipping cost is really a pain in the behind. The order is out.. sure, I am getting an email that this will take months. Not the plywood but the Sitka Spruce.

Today I made the second left-wing compression rib, two more to go and 14 in total.

Then I  used the bending dohickey for the first time today, and it worked well. At least the tubing did not kink. There was a learning curve, but in the end, it went fine. Unfortunately, my workspace is limited, and I did not want to cut the tube before making the first bent in case something would go wrong. So I had to relocate my pattern and the bending blocks after the first bent—a little cumbersome. It was good that I had the pattern on paper.       
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 27, 2021, 07:06:05 PM
Looks very nice. Wait until you bend the aluminum. There is even more spring back. On a couple of my bends I had to move my block inward twice.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 28, 2021, 06:32:13 PM
... There is even more spring back...

No doubt, lots of spring back. I had to move the blocks as well, more than twice.

I have not been very productive, at least not in the shop. This is my "work weekend," so I expected not to get a lot done. 

I transitioned more of the plywood parts into the CAD system. As soon as my plywood shows up, the CNC can start cutting pieces.

While bending the trailing edge, I realized the significant difference in diameter; 3/8 tubing is connected to 3/4. To keep the center of the tubes on the same level, I 3D printed some little blocks. They keep the 3/4 tubing a little more than 1/6 about the surface, and both tubes center on the same height.

Also, the material to make the hinges arrived today. The 7/8" 0.058 tubing fits perfectly over the 3/4". So far, so good.  What is not so perfect are my welding skills. So that is going to be interesting. I welded many test pieces in the last couple of weeks, it has gotten better, but the results are still light years away from producing something usable. 
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 28, 2021, 07:14:39 PM
Beautiful tubing spacers. I just used wooden blocks. A1 does not go anywhere! Don't bother making it.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on August 29, 2021, 06:04:53 AM
Since I already had them made..I sawed them off and used them for a filler.
(https://static.imgzeit.com/large/d291cbc463cad233/IMG_20200625_083329338(1).jpg)
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 30, 2021, 04:50:01 AM
Beautiful tubing spacers. I just used wooden blocks. ...

Thanks, they look cool, but wood might be much better, not sure if the 3D printed spacers will stand up to the task. PTE printed stuff is not the strongest. I will see how it goes.

I have to get serious about the rivets I want to use for the tail. It will be either the stainless steel ones called in the plans and recommended here or Cherry Max, from which I have some, but probably not enough.
I made some tests with the Cherry Max CR3213, grip length 01 1/32 (.032) 1/16 (.062), which has a minimum shear strength of 505 lbs.

I can pull them either with a hand tool or my pneumatic rivet puller. Either way, they seem to sit OK.

In the 3/8 tubing, the length becomes an issue. For the test, I drilled all the way through the tube. If there is no hole on the tubing's opposite wall, the rivet might not sit flush with the aluminum sheet when pulling.
Also, the rivets cannot sit as opposed to each other they need to be spaced differently on the front and back, at least in the 3/8 tubing.
In the pictures, the rivets are not exactly on center that needs to be improved as well.

Side note, I used the Olfa knife to cut the aluminum sheet and it worked great. Nice clean cut.

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 30, 2021, 06:58:52 AM
Marson SSB4-1S rivets fit a 3/8" tube from opposite sides perfectly. I got mine from Bay Supply using eBay.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 31, 2021, 04:32:52 AM
Convinced, I will use stainless steel rivets as well.  :grin:  The Cherry Max design with the mandrel sticking out doesn't fit the same way.

I did the first aluminum rib for the rudder fin last night. Cutting the material with the Olfa knife was really easy. I had some thin adhesive-backed neoprene rubber lying around from another project. I used that to cover the back of a metal ruler. That prevents the metal ruler from sliding around on the aluminum while I make the cut.
I bought the cheapest bending brake from Harbour Freight, not a delight, but gets the job done.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 31, 2021, 07:00:04 AM
Nice looking rib. A suggestion: if you cut off the small triangular piece overlapping the LE or TE, your gussets will lay more smoothly against the tubing.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on August 31, 2021, 06:47:56 PM
Funny, I thought about it ... you are right. The corner should be cut off. Thanks.

As I said, the Harbour Freight bending brake gets the job done, likely because the material is so thin. It's really cumbersome to work with the F-clamps, but that is how it is. The internet is full of videos on how to pimp your cheap Chinese bending brake. This is what I really hate on that stuff; if you buy it, you always get a new hobby for free  ::) . Anyhow, for the handful of ribs, it's gonna be OK. If I had to make 100, I would look for something else.

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on August 31, 2021, 07:59:54 PM
Looks like that HF brake is working fine. The bends in your rib look straight and crisp. Very nice work!
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on September 02, 2021, 06:11:49 PM
Chris, a suggestion: if you haven't already done it, you might put a small radius in the root of your rib bends.  Al does not like sharp 90* bends.  The thicker the Al the more important; it tends to crack.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 02, 2021, 07:06:34 PM
Chris, a suggestion: if you haven't already done it, you might put a small radius in the root of your rib bends.  Al does not like sharp 90* bends.  The thicker the Al the more important; it tends to crack.

Thanks, will try with the next bends and see how that works.


Looks like that HF brake is working fine. The bends in your rib look straight and crisp. Very nice work!

Thanks, the brake is working better than expected, just the handling is somewhat cumbersome.


Things slow down a little bit. I did not get the plywood so far, so I can't make the parts I need to make rib #7 and so on. I think I start sanding the ones I have and change my jig a little bit so I can make those ribs with a K-block and the like.

The stainless steel rivets are ordered but have not arrived yet. Anyhow, I still need to clean up the aluminum ribs and make the gussets, enough to do until the rivets show up.

And there are still the hinges waiting to be made. I need to have enough time to approach this without pressure, and I have to make some test pieces first and see how it goes.

Today I made only one aluminum rib for the rudder fin, and they are all done now. Actually, it was much easier than I had thought. Cutting the thin aluminum with the Olfa knife is really easy and gives good and clean results. A big help is the rubber backing of the ruler. Before that, the ruler slipped around on the aluminum, and I had to push on it really hard to avoid that. With the rubber backing, it sat rock stable and did not move at all, so I could concentrate on guiding the knife.

Unfortunately, there will be no time for building during the holiday weekend.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 02, 2021, 07:12:54 PM
Rudder looks great. After trimming all the rib ends it will be ready for gussets. When bending the gussets, use a piece of tubing one size smaller than the one the gusset goes on. For example: use a 1/2" tube to bend gussets that will go on a 5/8" tube and a 5/8" tube for 3/4" tube gussets. This allows for spring back so the gusset will fit the appropriate tube tightly.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 06, 2021, 11:08:31 AM
... When bending the gussets, use a piece of tubing one size smaller than the one the gusset goes on. ...

Thanks, I can see that this will help keep things nice and tight. I will definitely do that.

Here is an update on the recent activities.

I could not use the entire weekend to make progress since the family demanded two days without basement activities.  :grin:

My plywood arrived while we were not here. Faster than I thought. Even though nicely packed, the whole package was already warped, and the sheets are pretty bad. I think I let them rest on a flat surface and see what happens.

I still have a good amount of baltic birch plywood and also some 1/4". I made the test pieces from that. Today I tested if the glue is waterproof. It is definitely not. Only 2 min in boiling water were enough, and pieces started to separate without any force. So no way to use that.

Before I continue with the ruder fin, I have to make the hinges. That requires welding, as we all know. Hence today, I worked on my welding skills. They are still a big hurdle.
I welded 4130 5/8 tubing with 0.035 wall thickness and one pair of 7/8 tubing with 0.062 wall thickness.  First, I welded pairs, and then I welded all pairs into one big piece.  Lastly, I welded on the 7/8 to the 5/8 tubing. I used a 1/6 tungsten and 3/32 and 1/16 welding rod.
It looks pretty bad, mostly too hot, I guess. At least I made it from "only holes"  to "only some holes."  ::)
To be continued.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Vince Carucci on September 06, 2021, 11:36:09 AM
Those welds look about normal when first getting started. Try to develop an understanding of what went wrong, then practice-practice-practice!

My wife bought me a Meco Midget (https://www.tinmantech.com/products/welding/meco-torch-accessories/meco-midget-torch.php) for my birthday one year. It really increases your control. If you elect to use a standard torch, just make sure you have a nozzle small enough for thin wall steel tubes. [see the attachment for sizes]

The EAA has a BOOK (https://www.eaa.org/shop/product-detail?i=941&pi=926&pr=2516542) and a DVD (https://www.eaa.org/shop/product-detail?i=941&pi=926&pr=2677581) on gas welding of 4130 steel. The DVD is amazingly helpful. 

I've been tacking and welding up my frame this Summer and I can see an improvement every day. 

Good luck and hope to see it at AirVenture one year. 

Vince
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Vince Carucci on September 06, 2021, 11:43:36 AM
One the second thought, I'm looking at your stack-of-dimes and the steel table. You're probably not using gas are you?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 06, 2021, 11:44:06 AM
Lots of good areas on your test pieces. Looks like you are ready to weld the actual tubes.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 06, 2021, 05:17:31 PM
... Those welds look about normal when first getting started. ...

Sorry, I should have mentioned it. It's TIG welding. Since most of it will likely happen in my basement and Grage, I will not use gas welding. My wife is going to divorce me in no time when I do this. She was already scared about the Argon cylinder. Honestly, gas welding in the basement doesn't give me a warm and fuzzy feeling either.

This Meco Midget Torch is nice.

Lots of good areas on your test pieces. It looks like you are ready to weld the actual tubes.

Guys, thanks for the positive comments on my welds. I appreciate that.

I think it's still too hot. Once I have established a puddle, I can't really speed up because I will lose it, and if I try to reduce amperage with the foot pedal, I lose the puddle as well. So there is lots of room for improvement. Practice is what is needed.

Anyhow, I decided to give it a go. At least on a short piece. The result seem to be OK on the outside. The inside of the 7/8 tubing looks pretty rocky, that's not going to fit on the aluminum tubing anymore and will need some work. I will need a reamer to get this back to the desired diameter.

Side note. I used a circular saw for metal to cut off the pieces, not ideal, a metal band saw would probably be better but that is all I have.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 06, 2021, 05:59:01 PM
Wish my welds looked that good! The roughness inside the larger tube just shows you got penetration. I had to smooth out the inner portion of my large tube before it would slide smoothly over the 3/4" aluminum spars. I used a small drum sander on my Dremel for that. I did have to use a reamer to make AN3 bolts fit the 5/16" tube.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 07, 2021, 05:56:02 PM
Thanks, good idea with the Dremel, unfortunately, I "smoked"::)  my Dremel tool recently... so I need a new one or something else.

Today, nothing exciting happened. I tested the fit of the K-block and gusset into one of the compression ribs and figured that the K-block needed to be changed to align with the K-block gusset perfectly.


Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on September 12, 2021, 07:05:15 AM
Quote
I think it's still too hot. Once I have established a puddle, I can't really speed up because I will lose it, and if I try to reduce amperage with the foot pedal, I lose the puddle as well. So there is lots of room for improvement. Practice is what is needed.

Yes, it's too hot. You should be set at about 65 amps. I think some of your problem is too heavy of filler rod. When you dab, it chills the puddle, you need to up the heat, etc.
.035" filler is as big as you'll need.
Of course, your hinges are airworthy. Keep practicing. TIG has a *big* learning curve.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 13, 2021, 06:04:12 PM
Hi all,

I am pretty busy at work, so I had not had so much time to work on the eagle.

Yes, it's too hot. You should be set at about 65 amps. I think some of your problem is too heavy of filler rod. When you dab, it chills the puddle, you need to up the heat, etc.
.035" filler is as big as you'll need.
Of course, your hinges are airworthy. Keep practicing. TIG has a *big* learning curve.

Yep, TIG welding is an art, a little bit like Helicopter flying. You need to control a lot of things at once and keep them in balance.  I am working on it, but still not sure if I am going to make my own fuselage, we will see where I am in a couple of months.


So here is an update.

I stopped making ribs. Instead, I made a mock-up rear spar. I am currently sanding the ribs I have and then putting them on there to see what to do next and how it looks like. I make them specific for their location on the spar.
Rib #7 gives me some headaches currently, even though that should be straightforward. It looks like there are a couple of variations possible, and I just have to decide on one of them.
So I made all K-Blocks out of Hydrotec Meranti. I made the aileron stiffener of 0.125"/1/8 birch ply. Here, I am somewhat confused. The IronDesign supplemental plans show the aileron stiffener from 1/8" ply, and we should make 4 of them.  In the videos, it looks like there are two versions. One might be 0.125 or even 0.25 and one 0.8mm. However, the longer I stare at it, the more I get an idea of how to do it.

I continued working on the aluminum hinges. Still somewhat undecided if they are a good idea. They fit perfectly. I cannot make them like the ones in the video, but if I use 3 for one hinge, they come pretty close.

Lastly, I started making gussets for the rudder fin. The hint of bending the gusset around a tube one size smaller works great. That way, they fit really tight, and that's what we want.

I need to stop doing too many things at once. The shop gets messy doing that, and I cannot do a good job in a messy shop.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 13, 2021, 08:35:50 PM
On your aileron stiffeners, if one of them is labeled A1, do not bother to make it. It does not go anywhere. I also added a 0.8mm ply piece on the opposite side of the 1/4" doubler for rib #7. Probably just added weight for no real benefit.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 14, 2021, 05:57:06 AM
Keith, thank you for making this picture. That is very helpful. It looks like you made a very big aileron stiffener on the root side. That seems to make sense because, with that, the support goes into the wing rather than stopping at the edge of the "aileron cut out." That is something I am going to copy.
A K-Block inside the rib. That is something I am going to do as well. If I understand that correctly, I would need an additional K-block on the wing tip side of this rib so that the aluminum sheet can rest against something in this area. I can put another K-block there, but I probably make a k-block gusset out of 0.25 plywood.

On your aileron stiffeners, if one of them is labeled A1, do not bother to make it. It does not go anywhere. ....

Very true, unfortunately, I did that already.

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 14, 2021, 06:54:43 AM
You are correct about the extra K-block on the aileron cove side of the ribs. The cove filler needs something to attach to. I did make my 1/4" doubler longer than the Iron Design drawing. Here is a link to three YouTube videos by Iron Design about the ailerons. Can be a little confusing. https://www.youtube.com/watch?v=gsGA8s2uxNY&t=207s
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on September 15, 2021, 06:11:09 AM
(https://www.eaglersnest.com/forum/index.php?action=dlattach;ts=1631581449;topic=2400.0;attach=5446;image)

That's a seriously sturdy hinge.. :grin: tabletop cnc mill? Your fabricated hinge would have been fine, though.
I see you are putting the hinge hole in the wing jig. Locating everything involved with a pin in the jig pays big dividends at assembly.
Nice work..
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 15, 2021, 11:13:19 AM
...Here is a link to three YouTube videos by Iron Design about the ailerons. It can be a little confusing.

Thanks for sending the link, I have been through these videos quite a couple of times, and it can be somewhat confusing. I think I have an idea now about how I will do it. Getting the first-hand experience from somebody who has done it helped a lot.


That's a seriously sturdy hinge.. :grin: tabletop cnc mill? Your fabricated hinge would have been fine, though.
I see you are putting the hinge hole in the wing jig. Locating everything involved with a pin in the jig pays big dividends at assembly.
Nice work..

Thanks. I agree; both hinges will probably be fine. I am not an engineer by any means, so all I know is that I don't know what I don't know. That always comes into my mind when I deviate from plans. So I am still not sure what hinge I am finally going to use. For the steel ones, I will need an expensive reamer to make them fit nicely. The material for the other ones I have is still lying around.
I will make more of the steel ones and see if I can do a better job with welding: thinner welding rod and less heat.

Yes, the CNC is a half DIY tabletop CNC router with a working area of almost 2X4. It's pretty sturdy and does non-ferrous metals with very reasonable precision if certain parameters are met. 

I also made the rudder horn from 1/8 6061. Aluminum is always causing a big mess especially combined with mist cooling.
I made the CAD file for the rudder horn after a night shift and paid the price. So I had to make a second and piece.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 15, 2021, 11:28:46 AM
I made my rudder and elevator horns a little differently. They angle forward so the cable attach points are in line with the hinge pivot points. Hoping to have less cable slack. On elevator it gave me a little more weld surface.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 15, 2021, 05:20:49 PM
That looks pretty good.
How did it work out for you. I understand that your plane is already in flying, correct ?

My flying experience is limited to Piper Cessna and the like. I always hated the cable slack in our Piper 160 Cadet. For a while I flew DA20 Katana, this plane has pushrods, at least for the aileron and elevator. Very precise steering, no comparision to the Piper. So I would look forward to a solution that has the least amount of slack.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 15, 2021, 05:33:32 PM
No, not flying. Probably next year. I'm sidelined with a hospital stay and bout with Covid. Taking a couple of months out of my life, due to my age and general health.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on September 15, 2021, 06:11:49 PM
Kam sorry to hear about the covid; our prayers are with you.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Dan_ on September 15, 2021, 07:44:11 PM
Tell them to hit you with those monoclonal antibodies... 

I know a guy that got that infusion and dint even have to go to hospital.  They told him to for sure not get the vaccine for 90 days thereafter.

https://www.youtube.com/watch?v=Le-3MIBxQTw (https://www.youtube.com/watch?v=Le-3MIBxQTw)
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 15, 2021, 08:43:19 PM
Thank you all.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 16, 2021, 06:57:51 AM
No, not flying. Probably next year. I'm sidelined with a hospital stay and bout with Covid. Taking a couple of months out of my life, due to my age and general health.

Sorry to hear that, COVID is no joke. Unfortunately, I see that every day. I hope you make a 100% recovery so you can enjoy flying your eagle next year.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on September 20, 2021, 06:40:44 PM
Pilo, are you aware of the push-rod solution for elevator control that several builders have implemented?  I made it on my XL. It's fairly straight forward.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 22, 2021, 07:58:10 AM
Pilo, are you aware of the push-rod solution for elevator control that several builders have implemented?  I made it on my XL. It's fairly straight forward.


Da,

Thank you for mentioning that.
A while ago, in the nearly infinite space of the Legal Eagle universe I came along some guy who had implemented pushrods at least for the aileron. Can't remember where that was, it just flew across my eye and disapeared in the universe of pixels and bits. I would appreciate more information if possible. Even though I like the idea of pushrods very much, as an unexperienced builder this would probably be too much modification of the original plans.
However, I am really looking forward to get more information about the foldable wings. That is something I am very interested in.
Both have the downside that they will likely add weight to the bird.


Here is my update from the last couple of days.

I wasn't able to accomplish much because I had to work the entire weekend. I try to stick with doing a little bit every day.

I sanded almost all of the 18 wingribs I made so far. I used an oscillating sander with 220 grit and made a couple of sanding sticks with 180 and 220.
I continued with rib fabrication, currently ribs with the K-block and the K-block gusset.
Unfortunately my jig becomes more and more contaminated with epoxy even though I try to work as clean as possible. As an unwanted result of that I cracked another rib while getting it out of the jig. Victim number two,crap. This is pain in the behind, but not really a problem since I have surplus material.
I have tried wachs on the jig but that didn't work for me. Yesterday I found this mold release agent which I have used on silicon molds. I tried it and it was much easier to get the rib out of the jig than it was before. So I will use that for the rest of the ribs. 

I also made the aileron stiffeners that will cover the whole rib behind the rear spar from Lloyds approved Meranti plywood.


Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 22, 2021, 12:31:36 PM
Nice work. I really like the way you designed your rib #7 stiffeners. I got my ribs out of the jig without breaking by sliding a skinny stainless steel ruler back & forth under the rib. Broke the T-88 loose every time.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on September 22, 2021, 06:56:48 PM
I saw some aileron push rods. They were on a DE/CE.  I don't think anyone has done them on an XL. Remembering where you saw something and how to get back to it is, for me, extremely difficult.  Here are 2 elevator push rod pic sites: click on (co) single seaters XL-co p6-co converting to elevator push rod-go to Dan click on link. 2nd site: search tail wheel ( use search block at top of page, not the search in upper right hand corner) go to page 2 #36 Frank's XL. Another site which has many good pics is Darron  Crompton search scarf-co #19- go to p4- click on Dan's link.  This is very confusing, but it's the best I could do.  DA
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on September 22, 2021, 07:19:53 PM
Help me out.  What is Lloyds approved Meranti plywood. Where do you get it? aircraft approved?  Just wondering. DA
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 23, 2021, 07:07:00 AM
Nice work. I really like the way you designed your rib #7 stiffeners. I got my ribs out of the jig without breaking by sliding a skinny stainless steel ruler back & forth under the rib. Broke the T-88 loose every time.

Thanks!  I have a similar technique, but I think my main problem is that I am sometimes not patient enough.  ::)


Help me out.  What is Lloyds approved Meranti plywood. Where do you get it? aircraft approved?  Just wondering. DA


Thank you for pointing me to the information about the pushrods. I will see if I can find it.

Llyods  BS1088 approved Meranti plywood.

https://www.midwestboatappeal.com/marine-plywood-lumber/bs-1088/

BS 1088 is a European (British) standard for Marine plywood.

https://en.wikipedia.org/wiki/BS_1088

Germanischer Lloyd developed a standard for aircraft plywood (and much more) primarily used in Europe.

https://www.aircraftspruce.com/catalog/pdf/Germanischer%20Lloyd.pdf

Germanische Lloyd SE is now https://www.dnv.com/

Marine Plywood, like Okume, has been used extensively in European aircraft build. If I recall this correctly, Jodel and Robin have used Okume for their boxed main spar for a long time. Not anymore. I have read somewhere that they now use Birch plywood. https://www.robin-aircraft.com/en/ateliers/
Okume is very strong and light but not very rot-resistant, which is now given a reason not to use it in aircraft.

If you look at all the specifications, MIL-spec Lloyds, and the like, a big part is the glue. Water-resistant and boil-proof. Then the number of layers, the direction of the grain, no voids and the like. Birch seems to be the strongest but is also the heaviest.
As an example, Okume 4X8 sheet 18Lbs - Birch 4x8 sheet 25Lbs.

So, I would think aircraft approved means that the plywood meets all these criteria and/or is made specifically for use in aircraft. The latter is going to make it pretty expensive because somebody has to sign for it. I think certified marine plywood is pretty good stuff, but it is not explicitly made to be used in aircraft. However, it is used very often for that purpose. I think I read somewhere that the first Legal Eagle was made out of plywood from the "marine store."
At the end of the day, I would not substitute one material for another in load critical areas without testing. But the plans don't say anything about the type of plywood that should be used, or? The designer assumes that we will choose the appropriate material.
But how can we do that? We all would like to achieve the same results Leonhard achieved while testing the XL wing, correct? But we can only do that by using precisely the same materials. But we don't know what was used, at least I cannot find this information.

Anyhow, I am using Birch for the spars, Meranti and Okoume for other not-so-critical components. I use them because I have them in my plywood pile. Otherwise, I would probably use Birch throughout. Actually, I am trying to avoid the Okoume (see above), but I may not have enough of the Meranti.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on September 23, 2021, 03:14:27 PM
Thanks
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 27, 2021, 05:37:07 PM
Hi all,

Another update on the progress.

Not much happened over the weekend. We used the gorgeous weather to be out on the Chesapeake Bay with the boat.

Somehow I screwed up some of the K-Block cover gussets and had to make some new ones. Here the laser comes in pretty handy, easy to make just a few new ones.

Also, I made some of them out of 1/4" plywood on the CNC. They will go on rib #7 and face the aileron, also on rib #12.
The Irondesign videos show a normal K-block covered by a 0.8mm K-block gusset on rib #7, so why not make a thick K-block gusset, everything in one piece.
The screenshots are from the Irondesign videos.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on September 27, 2021, 07:35:25 PM
Not shown in your last photo is the K-block the aileron cove cover attaches to. Of course, you could use two of your 1/4" K-block gussets in place of the K-blocks.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on September 28, 2021, 06:07:56 PM
Good picture, thanks.
Obviously, an excellent idea to use two K-blocks to have more surface area to glue the cove cover on.

Today, I had just some time cleaning the shop and arranging the ribs on the mock-up spar.
Now I have to do the ribs 7, 12, and 13. But before that, I need to make a hinge pin to perfectly line up all the hinge holes.

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 02, 2021, 04:15:15 AM
Hi all,

I am in the process of making ribs 7, 12, and 13, which causes more brain twist than likely necessary.
Because I cannot fit the plywood covers in my jig and the space inside the rib around the hinge hole should be filled anyhow, I made some kind of a hinge hole locating block. Then I made a Delrin hinge hole locating pin. With the hinge hole positioned, I can later attach whatever piece of plywood right and left to the rib and have the hinge hole always perfectly located.
The hinge block between ribs 12 and 13 will be glued onto the hinge hole locating block. That assembly should be strong enough.
Now I can finish these last ribs and get the jig of my workbench. That will free up space to start with other stuff.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 02, 2021, 06:42:37 AM
One question to the control surface hinges.

I am going to make the aluminum version, not because they are better,  just because I can.

However, there is one thing I am not sure about. In the Facebook group, somebody mentioned increasing the distance of the steel tubes before welding by about 1/16 inch makes things easier. See screenshot.  But that also causes the gap between the control surface the stabilizer to widen.
Any thoughts about that?
I did the first version of the aluminum hinges with increased space between the holes. With that, the gap between the tubes already looks like a lot.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on October 02, 2021, 08:13:45 AM
At our speeds I don't think a little more gap is going to matter. Unless you use a gap seal, I'll bet about the same amount of crossflow exists in a 1/2" gap and a 3/4" gap. I don't know if an excess gap would contribute to flutter, but maybe there is an article about this somewhere on the Internet.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 08, 2021, 06:50:25 AM
Cross flwo and flutter is both not really great. I may change the hinges back to the original form.



I am still in business, work is just very intense these days, thanks to COVID, and there is not much time left in the day for progress on the eagle project.

Still working on the last wing ribs, had to make some new gussets and pieces since I broke two ribs while getting them out of the jig.

I think my hinge hole location block works like expected, no gussets behind the rear spar on these ribs, they get covered with 0.08 mm ply on one side and 0.25" ply on the other. That should give plenty of stability.

On a very positive note, my spar wood arrived this week, way way earlier than expected. So I can continue working on the wings.

Not so positive... when I made a list for my aluminum supplier, I copied the information out of the plans. That may have been a big mistake. Now I am the proud owner of aluminum tubing 1.25" in diameter for a lot of money that I probably not going to use. I am open to suggestions on what else I can do with that. Maybe a roll cage for my sprinter van ...   ::)  :grin:
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on October 10, 2021, 01:48:27 PM
Quote
Now I am the proud owner of aluminum tubing 1.25" in diameter for a lot of money that I probably not going to use.

Uhh, while much of the materials and hardware list is suspect.. :) 1 1/4" diameter is correct for the spar aluminum.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on October 10, 2021, 02:17:17 PM
I thought they were for the struts?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on October 11, 2021, 03:33:20 AM
I thought they were for the struts?
:grin: Duh. Think one thing, type another.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 11, 2021, 05:01:28 AM
... while much of the materials and hardware list is suspect.. :) ...

Unfortunately  ::)


I thought they were for the struts?

That is what I thought as well.

However, under "Struts," it's mentioned that extrusions from Carlson Aero were used, obviously not the stuff listed in the material list under Aluminium.
Has anybody used round tubing for the struts? Sometimes hard to see in pictures or videos, but I think I have seen mostly oval-shaped extrusion rather than round tubes.
I checked the Carlson Aero website, looks like these tubes are roughly 8$ per foot if I understand their pricing correctly. The transport costs will be very high though.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Tom XL-7 on October 11, 2021, 06:00:11 AM
many fly with round struts they are less expensive but more importantly much lighter. the Carlson or rounds still require jury struts.
if you a concerned about the drag round things have been faired since the beginning of aviation
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 11, 2021, 06:48:56 AM
many fly with round struts they are less expensive but more importantly much lighter. the Carlson or rounds still require jury struts.
if you a concerned about the drag round things have been faired since the beginning of aviation


Thanks for your input, those are important points to think about.

I am not really concerned about drag, not at 60mph, and I am thinking about using the Hirth F23 engine, which has 50 hp.

That is the tubing I got from my metal supplier.

1.25" OD x 0.058" Wall x 1.134" ID Aluminum Round Tube 6061-T6
weight per foot 0.26 lb.


This is from the Carlson website, assuming that their small struts will do it. They compare them to:

Stronger than but compared to 1.275 Dia x .065 wall 6061T6 tubing

ULTIMATE = 18,012 PSI
YIELD = 15,947 PSI
SHEAR = 11,637 PSI
AREA = .431 SQ IN
CIRCUMFERENCE = 5.625
WEIGHT = 0.517 #/FT
126 ” LG – $71.00 / LENGTH


As one can see, there is a significant weight difference. Round 0.26 lb and oval-shaped extrusion 0.517 lb /FT.
If all these numbers are correct, struts from round aluminum tubing could save about 3-4 lb, which seems to be a lot.

It also brings up the question of why the designer has chosen extruded oval-shaped struts for his airplane? Sticking to lightweight construction would have called for round struts, but only if they are not markedly inferior in strength compared to the extruded oval struts.

Anyhow, lots of time for more research until I have to make a final decision about the struts.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on October 11, 2021, 10:31:03 AM
Round struts are plenty strong. Putt Putt (high time LE) used round struts with a thin aluminum fairing. I don't think there were any issues. He even left the jury struts off at times. I plan to use round struts to save weight & money.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 11, 2021, 10:59:39 AM
Thanks!

Since my last posting, I went into the garage and looked at the tubing. Pretty substantial stuff. I am going to stick with it as well.

Today I finished sanding all the ribs. No more making ribs... if I don't break any  ::)

Here are a couple of pictures showing rib number 7 with all that will be attached to it. Not shown is the hinge block.

My laser is too small to make the whole piece so I made two pieces from it. Should not be a problem since it will be glued to the "hinge hole locating block".

Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on October 11, 2021, 02:04:15 PM
Quote
I am going to stick with it as well.

Attaboy. The round tubing is plenty strong. I would think the lack of streamlining will show up mostly on landing. I'm at least planning on carrying some power all the way to touchdown until I get some experience with it. As Keith said, it would be easy enough to fair it if necessary.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on October 11, 2021, 06:27:40 PM
no one asked, but I'm also going with the round struts.  How could it be wrong with so many old and experienced builders using them
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on October 11, 2021, 06:33:01 PM
I like the look of your Al strut fairings.  What type of Al and what thickness are you using?  TKS
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on October 11, 2021, 08:03:02 PM
The strut fairings in the photos are not mine but they are 2024-T3. I do not know the thickness. I've heard some people made them from roof flashing (Lowe's). I think this method is similar to Rockiedog2's way on Putt Putt.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 16, 2021, 05:35:33 PM
Hi all, here is a brief update on what's happened in the shop

As mentioned before, all the wing ribs are done and sanded. Yesterday additional Birch ply arrived from ACS. Now I have everything to make the wing spars. However, I realized that I had kind of underestimated the size of the wings. I am not sure anymore if I can get them out of my basement. To be 100% sure, I have to make a wing-sized frame out of scrap wood and test it. The last thing I want to experience is that I can't get the wing thru the door and up the stairs.

Meanwhile, I finished the gussets for the rudder. One side is drilled and mounted with clecos. I thought I had some leftovers aluminum angles of the correct size, but I did not,  so I have to get some before continuing.

On the rib that is carrying the rudder horn, I increased the flank height to 0.75", making it easy to bend the top rim of the flank inwards. I hope that gives the rib a little more stability. I made the rudder horn gusset on the CNC router, so no problem making the slots.

I may have made the gussets a little bit too big. As you can see in the picture, there is just enough space for one hinge piece between the end gusset and the one carrying the rudder horn. However, I can't see why this would make a problem down the road, but maybe there is something I don't know or haven't seen yet.

Somehow I got second thoughts again on what hinge version to use, the aluminum ones or the steel ones. I used several different abrading tools, but nothing really was easy and the result less than desirable. I am wondering how I can improve that. I made a new piece of hinge material, and the inside looks again pretty rough. I am wondering if that would be better with some Argon back purging. Unfortunately, my Argon regulator has only one flow meter.





Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on October 17, 2021, 09:08:47 AM
Quote
I used several different abrading tools, but nothing really was easy and the result less than desirable. I am wondering how I can improve that.
I've said many times that the right tool is 2/3 of the job. Get yourself a die grinder or even a Dremel or clone. You have to have some serious rpm to grind.
Quote
I am wondering if that would be better with some Argon back purging.
Sure it would.. but you really don't need that. TIG is not learned in a day, grasshopper..more practice.  :)   :)
Nice work, btw..
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Kamcoman77 on October 17, 2021, 11:21:38 AM
Like Chuck says, the Dremel or high-speed die grinder is the way to clean up the 7/8" tube interior. I had some pretty heavy clean-up to do on some of my hinges. An 80-grit sleeve on my Dremel did the job.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on October 17, 2021, 02:00:19 PM
concerning the space for the hinge, I don't think it will be a problem but it looks like you can pick up some space by squaring off the bottom of the upper gusset and trimming back the top of the bottom gusset. Traditional edge distance is two diameters from hole center to edge of sheet 1/4" for 1/8" rivet. If it were me (I?) I wouldn't be afraid to cheat a little on edge distance in this case. Of course it's your call.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on October 17, 2021, 02:07:06 PM
one other thing.  I know that you're not too keen on gas welding in your basement, and rightly so, but another benefit of gas welding is that the welds are much softer than tig or mig welds.  Gas welds can be drilled and filed. 
Title: Re: Legal Eagle XL in Pennsylvania
Post by: CHARLES DEBOER on October 17, 2021, 07:58:42 PM
Like Chuck says, the Dremel or high-speed die grinder is the way to clean up the 7/8" tube interior. I had some pretty heavy clean-up to do on some of my hinges. An 80-grit sleeve on my Dremel did the job.
How about a 7/8" drill bit?
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on October 18, 2021, 06:59:06 PM
I've tried drill bits, they're scary.  They want to catch and depending on how powerful your drill is, it can really throw you.  A 7/8" reamer would be a better choice.  However, that Tig weld is mighty hard and may ruin the hss reamer.  Probably the best bet is a die grinder with a stone.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 18, 2021, 07:34:09 PM
I've said many times that the right tool is 2/3 of the job. Get yourself a die grinder or even a Dremel or clone. ...

Like Chuck says, the Dremel or high-speed die grinder is the way to clean up the 7/8" tube interior. ...

Thanks for your input.
I am listening.
In hindsight, I am not even sure anymore why I have even tried to use my electric drill for that.  ::)  It was like enlightenment, and I drove down the road to Lowes and got the little blue sucker. That's all you can get on a Sunday evening in central PA. Only Harbor Freight would probably be worse. Anyhow, the thing got the job done. In the end, the limiting factor is my slightly underpowered air compressor. That thing was never meant to drive air-hungry rotary tools. Just brad nailers and the like, now and then a little POP, not more.

... I know that you're not too keen on gas welding in your basement, and rightly so, but another benefit of gas welding is that the welds are much softer than tig or mig welds.  Gas welds can be drilled and filed. 

DA, I may have to outsource the process to my garage. In that case, I will give gas welding a second thought.

Not entirely sure, but I have the impression that the material gets harder in the weld-affected zone.

That brings me to the next point.

How about a 7/8" drill bit?

I would think, without having tried, that when using a drill bit, the workpiece (hinge) needs to be aligned and secured very thoroughly. Otherwise, the drill bit may deviate from the center due to the hard material in the weld affected area and cuts more into the softer material on the opposite side. So ideally, in case I would build a rocket ship or the like, I would clamp this in the lathe chuck, center it and use a boring bar to bring this to correct dimensions.

An alternative way could be removing most of the surpluses material in the weld affected zone with the grinder and then using a reamer of the appropriate size. However, a reamer of that specific size is very expensive.

The "only using the grinder" version is already pretty good. Just use the right tool ... :grin:
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 18, 2021, 08:04:45 PM
I've tried drill bits, they're scary.  They want to catch and depending on how powerful your drill is, it can really throw you.  A 7/8" reamer would be a better choice.  However, that Tig weld is mighty hard and may ruin the hss reamer.  Probably the best bet is a die grinder with a stone.

Somehow I missed this post.
Those were exactly my thoughts. I was also afraid to ruin a very expensive reamer.

Anyhow, a real grinder gets the job done. It's all about RPM, much like engine size (displacement) in cars ... just kidding  :)) .

BTW I made a little video showing my hinge-making process.

https://youtu.be/rq9TdRbOoDs
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Chuck in Indiana on October 19, 2021, 04:51:13 AM
Quote
In the end, the limiting factor is my slightly underpowered air compressor. That thing was never meant to drive air-hungry rotary tools.

Just a heads up. What will happen is your underpowered compressor will get really hot. That will condense moisture and rust your (plenty good) die grinder into oblivion in short order. At the very least, put a decent water trap in line, and drain it religiously. (proper tools and all that..)  :)
Yes, a 7/8" reamer would do it (with proper fixturing and cutting fluid). Don't even think of a drill.
I would have clamped it in your table top mill and cleaned it out with an end mill. If you don't have 7/8", 3/4" would have eaten it out to where just some light die grinder work would have cleaned it up.
NOW.
Never wear gloves or long sleeves when running machinery that rotates. I cringed when you were wearing gloves  using that disc sander. It is one of the most dangerous tools in the shop, and if it grabs some cloth it is an explosion. Trust me.. :o
Nice video, and nice work..
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Dan_ on October 19, 2021, 12:19:38 PM
My uncle by marriage was a master electrician.  He had a 90 degree heavy duty drill with the extra handle on it. All the plumbers wanted to use it.  He always cautioned them about how strong it was.  He stopped loaning it out after it had a guy crumpled up in a corner and could not get his finger off the trigger...
:emoji_u1f601:
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on October 19, 2021, 03:25:52 PM
...At the very least, put a decent water trap in line, and drain it religiously. (proper tools and all that..)  :) ...

...Never wear gloves or long sleeves when running machinery that rotates. I cringed when you were wearing gloves using that disc sander. It is one of the most dangerous tools in the shop, and if it grabs some cloth it is an explosion. Trust me.. :o  ...

Thanks for the advice.

A water trap is on the list for quite some time... ::)

Gloves sleeves but also long hair (thank god I don't have that  :))  ) are a NO-NO if working on rotating machinery. I am well aware of that, which makes me look even more stupid, I know.
However, I would never ever wear gloves while working on the lathe, the mill, the table saw or the jointer, and the like, you name it. This Proxxon thing is not in the same leag you may have in mind. It's easy to stall the motor, doesn't require a lot of force. With that in mind, gloves may not be such a big problem, but regardless you are correct; it's a dangerous and bad habit. 


One more question for the group. As you can see in the picture, the weld seam did not penetrate all the way into the corner between the tubes.  Do you think that is a problem? Rust building without being noticed and at some point failure of the hinge?
I may overthink this.




Title: Re: Legal Eagle XL in Pennsylvania
Post by: Vince Carucci on October 19, 2021, 03:31:04 PM
Most of mine look the same way. I'm not concerned. I figure there should be some indication long before a failure. The forces on the rudder/elevators are very small for steel. So I will look for rust during pre-flights, post-flights, annuals, chapter picnics, and late summer nights while howling at the moon.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on October 19, 2021, 06:54:58 PM
As long as you got penetration in the sidewall of the big tube and the small tube I think you should be ok. Squirt a little glue or silicone in the void top and bottom.  That should take care of the H2O rust issue
Title: Re: Legal Eagle XL in Pennsylvania
Post by: Pilotarix on November 02, 2021, 11:24:05 AM
Long time no post here. The project came to a halt for a couple of days. There was just too much other stuff that required attention.

I restarted slowly with cleaning the shop and the machines, getting everything back in order. Then, I made a somewhat floppy wood frame out of a 2X4; that frame was the size of a wing 56" by 156". The only purpose of that thing was to check if I could carry a completed wing out of my basement. When we built the house, I got a second staircase installed that goes from the garage to the rear of the basement. That staircase has already been handy in many situations, and it allows me to get rather big and heavy items in the basement, aside from the fact that I don't need to carry every piece of wood through the house.
Anyhow, the wing will get out of the basement, which is good because it allows me to continue in the basement and not have to move the project into the garage.
Other than that, I cut many more hinge pieces from the stuff I welded and got closer to finalizing the ruder.
Title: Re: Legal Eagle XL in Pennsylvania
Post by: DA Miller on November 03, 2021, 12:09:26 AM
this is a test post. :))
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