Sunday, October 5, 2014

Ch 9.1: Main Gear Reinforcements (3 of 3)

Last But Not Least

Ok...down to the last strength reinforcements of the landing gear bulkheads.  This one beefs up the area between the forward and aft LG bulkheads themselves.   This is the area where the main gear bow will actually be installed.
Piecing together the template

The last reinforcement went so well using the template, I decided to try it again on this one.  I thought it might be the only way I was going to get the glass fibers running the correct direction all the way around.

I first pieced together a template using pieces of paper and tape.  I used a sharpie to mark the corner areas and planned to trace these on to the plastic before I wet the glass so I could get it positioned correctly on installation..

Since the area to be glassed has a major bend in it  (see right side of pic), I had to decide where to cut it in order to get it to lay flat for cutting the glass. It is mentioned in the plans that you'll have to cut the glass somewhere and overlap it or it will otherwise bunch up....but make sure you don't overlap on the hard points...these need to be flat.

Paper template
(as if looking down at the copilot's side).
Note the triangle cutout (top) where
the glass  will fold and overlap in the bend.
Looking around at other builder sites, I came across Charles Fernweger's builder site.   He showed a template that looked a lot like me a little confidence that I was on the right track.  He cut his from the front corner, where the three separate planes come together, diagonal up the 90 degree inside corner in the forward bulkhead.  When the template is laid flat, you get something like the top picture to the left.  The cut I made is represented by the open triangle.

Paper template
(as if looking down at the pilot's side)
Note the triangle gap is closed.
I closed this gap up with another piece of paper running horizontal until it met the other side of the open triangle like in the 2nd pic.  Note this is flipped as if for the other side.

When cutting the wet glass to shape, I made one cut from the location of the sharpie in the 2nd left pic, to the 4-way intersection.  The 4-way intersection is the corner where the three planes meet  (fwd upper bulkhead, fwd lower bulkhead, and fuselage side).  Now when I installed the glass, and it folds up, I had a side of excess glass to overlap onto the angled upper portion of the fwd bulkhead for a strong bond.  I hope that makes sense...EZ to do, hard to explain.

After the "all over" reinforcement is complete, there is one more 2xBID that goes over the hard points just like the other reinforcements.  Using the same process, I cut 2xBID 19"x 6" and laid it in from hard point to hard point.  EZly done.  (OOPS: The next morning when I completed the pilot's side I realized that I had accidentally made this lay-up with 3 ply's instead of 2...oh well...I guess a few extra once's wont hurt.)

Reinforcements Complete
Pilot's side, between the fwd & aft LG Bulkheads
Reinforcements Complete
Copilot's side, between the fwd & aft LG Bulkheads

All the fuselage main landing gear reinforcements are now done!  It's time to start working on the main gear bow itself.


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