Dave's XL F-71

[Larry H]

Hi Artic Dave,
Your fuselage is progressing nicely.
Is this photo an illusion because of the camera angle or is the bottom of your firewall higher up than 4" from the fuselage bottom in the passenger compartment? It looks like a really steep angle up in this photo.
Carry On

Larry H

[ArcticDave]

Thanks Larry. 
No illusion. My forward geometry is changed up a bit. I needed more prop clearance. Over the front visability took a hit though...

[Dave Stroud]

What engine, Dave ? 3 round ?

[Larry H]

I was just thinking about that severe angle up to your rudder pedals from the seat. I had already been thinking of lowering that angle on my plane from the plans dimensions.. I will leave the top horizontal and engine attach points at the original points but possibly drop the bottom horizontal some. When I get to my fuselage I'll check all of that and decide then. If I drop the bottom horizontal a little, I realize I may have to add another horizontal tube or angle braces at the lower engine mounting points.

Larry H

[ArcticDave]

What engine, Dave ? 3 round ?

I want to provide ample clearance for the Scarlett, but financial reality dictates I build a half veedub and be happy with that for now.  Hopefully by the time I can afford to buy a Scarlett from Frank...a few other guys will be flying them. Looks to be the perfect engine on paper. 
The main reason for the extra prop clearance is the rough terrain. I'm making Cub style struts with a bit more travel to soak up the rough ground. I need room for that suspension to work and not have to worry about flicking rocks into the prop. 

I was just thinking about that severe angle up to your rudder pedals from the seat. I had already been thinking of lowering that angle on my plane from the plans dimensions.. I will leave the top horizontal and engine attach points at the original points but possibly drop the bottom horizontal some. When I get to my fuselage I'll check all of that and decide then. If I drop the bottom horizontal a little, I realize I may have to add another horizontal tube or angle braces at the lower engine mounting points. Larry H

That's what I find appealing about the line of Eagles. Within reason you can change it up to fit the builder! 
I mocked mine up on the table before hand to verify the rudder pedals wouldn't be too high. I looked a little ridiculous sitting on a block of wood with my feet on a stack of lumber trying different configurations, but it set my mind at ease before bending the longerons. 

[ArcticDave]

Still pecking away at it. I love gas welding! I wish I had picked it up years ago. I always dismissed it as too old fashioned. Almost zero sparks compared to the mig and stick welding I have been doing for 30 years. It almost feels genteel...like a fine cigar and brandy should accompany me as I slowly puddle along. Quite the zen experience.

[scottiniowa]

What engine, Dave ? 3 round ?

I want to provide ample clearance for the Scarlett, but financial reality dictates I build a half veedub and be happy with that for now.  Hopefully by the time I can afford to buy a Scarlett from Frank...a few other guys will be flying them. Looks to be the perfect engine on paper.
The main reason for the extra prop clearance is the rough terrain. I'm making Cub style struts with a bit more travel to soak up the rough ground. I need room for that suspension to work and not have to worry about flicking rocks into the prop. 

Maybe I have missed it, when the question was asked, about raising the station (1st station-engine mount)  you stated that this was done for prop clearance, and that makes sense.   But you did not elaborate on "how much"  And what you did about the corresponding raise in top cowl area (frontal view)   Not that it is a great concern, as there are many aircraft with poor fwd visibility while on ground taxi.

You also mentioned "cub style gear"   Do you mean bungee?  or another type?   taller? wider?   Just curios...

[Dave Stroud]

Arctic Dave....back on page 2 of this thread you show a picture of a welded splice in the longeron tubing that you needed to perform to " extend" the 12' tubes that you had to a suitable length. In finishing that splice did you slip a sleeve of tubing over that welded joint and weld that on too ? Thanks.

[ArcticDave]

What engine, Dave ? 3 round ?

I want to provide ample clearance for the Scarlett, but financial reality dictates I build a half veedub and be happy with that for now.  Hopefully by the time I can afford to buy a Scarlett from Frank...a few other guys will be flying them. Looks to be the perfect engine on paper.
The main reason for the extra prop clearance is the rough terrain. I'm making Cub style struts with a bit more travel to soak up the rough ground. I need room for that suspension to work and not have to worry about flicking rocks into the prop.

Maybe I have missed it, when the question was asked, about raising the station (1st station-engine mount)  you stated that this was done for prop clearance, and that makes sense.   But you did not elaborate on "how much"  And what you did about the corresponding raise in top cowl area (frontal view)   Not that it is a great concern, as there are many aircraft with poor fwd visibility while on ground taxi.

You also mentioned "cub style gear"   Do you mean bungee?  or another type?   taller? wider?   Just curios...

Good morning Scott. I would have to look at my CAD drawing to give you the exact amount, but I believe the bottom of station #1 was raised around 4-41/2" above the LEXL call out. I mocked a seat in the cabin yesterday to verify headroom before tacking the top longerons, and visibility over the nose is great when it's level.  At 3 point, probably a different story. Thankfully this is such a small craft, that looking out the side while on the ground is a non issue for me.
The gear: It will be wider, longer and probably bungee. Easier to fine tune the compression rate and I have an entire roll of industrial grade 3/8" bungee. I could change the gear bungee every month for the rest of my life and not run out...:-)
The goal is 19 degrees at 3 point. Any more than that and the gear gets absurdly long, I think it would be better to raise the tail(like a Cub fuselage) if a person wanted a steeper 3 point angle. 19 degrees will be fine for me. Close enough to stall that it should help with lowering touchdown airspeed. I will be installing VG's on the wing, so stall should be at least that...and hopefully a bit higher.

Dave Stroud:
I used an internal sleeve in that splice. I turned down a piece of 5/8 x .063 to slip into the longeron. It's then rosette welded to the longeron. An external tube over the splice would work just as well. I just didn't want to be reminded of my screw up every time I looked back there. Lol...vanity I guess.

I got the top of the cabin jigged last night. Next will be the cabane struts. I'll put up a pic when its tacked together.

Have a good day gentlemen...I intend to! 80 degrees and tee shirt weather today in the big AZ. A welcome change from the record rainfall we've had this winter.

[Tom XL-7]

Glad to hear you used an internal sleeve. I also would have chosen the internal one for the same reason. 
But for the group at large, there are external sleeves including some that could be applied after the fact.



Download this 696 page pig
Don't print - cheaper to buy
Save it and use it 
Tom XL-7

[ArcticDave]

Good stuff there Tom. Thats where I got my scarfing info. 

Talking about that inner sleeve reminded me of a hairbrained idea I had while making the sleeves. In the final step of making them I sanded the last bit to fit the fuselage tubing. It occurred to me while sanding, that 4130 would polish nicely. If a fellow was REALLY trying to build as light as possible...just polish the fuselage and ditch the paint altogether. Might be hard to look at on a sunny day...but it would turn heads wherever it went.

[Tom XL-7]

I have thought of that. If I could figure out a failproof bond I would consider clear mylar for the covering. Would be one amazing educational tool.
 Dacron can be finished clear and ends up translucent. I have thought that would be cool. Just keep it simple-naked. 
 Polishing would be a lot of work. I would have to clear coat it. I would be afraid wax wouldn't last through an extended period of storage.
 Many alum wheels on cars are not polished but painted.  It's very durable and available in a range of finishes, even in shake cans.
For the "cheater" that might exist in a rare few of us. 
   Of course, I could always go P-hat pink; park it next to Spenser's 701; get a black light and open up a "head shop" 
Desert tan (tird brown) and clear finished dacron would be an easy way out and would hide some of my welds.
 Happy building Artic Dave
Tom XL-7

[ArcticDave]

Polished would require some elbow grease and it's longevity would depend on climate. Here in the southwest it is generally pretty arid, and a simple wipedown with a light gun oil would last a long time(years) if not stored in the weather. Having my airplane smell like Hopes #9 has a certain appeal...I love the smell of that stuff. 
I haven't decided on color yet either Tom. Black tubing with orange fabric would look great I think and still is my first choice, but a red fuselage and trim on antique white keeps popping up in my thought pattern. Kinda like this Savage Bobber...

[scottiniowa]

Glad to hear you used an internal sleeve. I also would have chosen the internal one for the same reason.
But for the group at large, there are external sleeves including some that could be applied after the fact.



 
Tom XL-7

picture worth 1000 words I hope

[ArcticDave]

Scott, that's a good illustration. Thanks for sharing it.
 My inserts were only  .0278 +/-  after final sanding. I am comfortable with that, but if anyone else needs to join tubing...err on the side of caution and use Scotts drawing.