Wings

[Kamcoman77]

Your printed nose rib looks great, but looks like it could be half as thick on the inside. The bottom piece is probably not even needed considering how stiff the arch portion is. I used aircraft grade 1/4" ply for my end nose ribs and 1/4" "hobby ply" (Midwest brand) for the interior ribs. I used 1" wide extruded foam with a crosspiece for my added ribs. After mockup, I decided that I only needed one foam rib between the ply ribs, except for the outer bay where I used two foam ribs. I used 1" thick foam because I wanted more support for the 0.8mm nose ply. Used T-88 for all joints. The nose section on my 1st wing feels very strong.

[Brock]

These nose ribs that I have were 1/8" too long.  So I cut them down.  But cutting squarly the ends of a hoop is a bit of a challenge.  3D printing to the rescue.  I made this jig to help guide each rib through the table saw.  Now they are all exactly the same length, and the length that I want.  Next is to draw and print up a jig that will hold them while I cut the stringer notch.

While I'm talk'n about 3D.  I did a  T88 glue test with the LW-PLA test cube.  T88 stuck to that foamy surface better than nails.  I eventually destroyed the cube and it was still stuck.  Too bad PLA can't stand the heat of sitting on the dash of my car (measured 153 degree today).  This is my test standard.  The PETG test sample did just fine but that is not yet made in foaming formula (LW-PETG).  So I have some LW-ASA on order to test out.

[Kamcoman77]

I made my nose rib notch jig from some scrap plywood. Ran the ribs through my table saw three or four times to get the 5/16" wide by 5/8" deep notch.

[Brock]

My nose ribs were not as carefully made and none of the holes lined up so I needed to remake them else have a different solution.  Here is what I printed up to hold the ribs for cutting.

The print had another hour to go but I got impatient and pulled it out early.  It was fine this way.

[Kamcoman77]

Nice looking jig!

[pappyadkins]

I agree... wish I had my printer back then... love this idea....

[Brock]

With the nose ribs all cut (except for some I hope to print) there was no longer any reason to delay working on the second wing.  So work I did.  Got it all assembled for trial rib fit and the gussets are all marked up where they need to be cut for things like compression ribs.  Sure is easy the second time around with most of the sub assemblies already finished. 

I better get on the phone and order that Oratex.

[Brock]

After printing and glue testing the (Light Weight) LW-PLA I was encouraged that 3D printed nose ribs might work.  But PLA can't stand the heat (I knew that).  So I ordered some LW-ASA, which is made for UV and more heat.  I printed a test cube and glued (T88) it to some plywood.  The next day I was very disappointed when I was able to easily pop it off.  See left side of the pic below.  Not wanting to give up so easily I tried again.  This second atempt (with the same cube) I lightly sanded then wiped with alcohol.  Seems that did the trick.  I broke the cube pulling on it and couldn't remove the stuck end by prying on it with my pocket knife.  Looking forward to printing a dozen or so of these.  They take over 2 hours to print but only about 4 minutes to start and walk away.  Is this what it means to "work smart not hard"?

[Brock]

Progress on the second wing is going at a blazing pace, as expected.  I did have one little oops today when I realized that I closed up both ends of the aileron before installing the aileron-spar-web.  Was saved with a (more than) bit of bending and some twisting to boot.  I thought the plywood would buckle but it didn't.  Whew!

[Kamcoman77]

Your work is really looking good. We did the same thing with one of our wings. Drilled the lightening holes after epoxying in place.