Ldg Gear Bulkheads

DON'T DO THIS! ONCE THIS LAYUP SAT FOR A WHILE THE WEIGHTS MADE IT TOO THIN!

I had to re-do the hardpoint layups for the landing gear bulkheads. After doing those layups and cutting the foam for the foam parts of the bulkheads, I realized that I had, in my zeal to weight down the layup, made it way too thin. The top picture depicts how I did this - DON'T DO THIS! As the epoxy cured, the weight on the flat boards made it thinner and thinner by the minutes until, once it was cured, it was about an 1/8th of an inch thinner than the foam it was supposed to be glued into.

22 layers of fiberglass (that takes a while!) covered with plastic wrap and 1" x 1" pieces of foam spaced around to make sure the layup doesn't squish too thin again.

For my second attempt, I cut 1" x 1" pieces of the same foam that the bulkheads were made of. I put these around the layup after it was finished and covered with plastic wrap.

Yes, the marble is quite heavy but since I had pieces of foam in between to make sure the layup didn't squish too thin, I added weight to make sure it wouldn't end up too thick!

I then covered the whole layup and the little pieces of foam with a large piece of marble I have around. The marble is, aside from being polished extremely smooth on one side, quite heavy. This time, when the epoxy cured, I had a nice, exactly the right thickness layup with a smooth surface on both sides. Worked great!

In this picture you can see the templates taped on the piece of hard point material and two of the hardpoints already cut out and sanded.

I tried something a little different on the landing gear hard points when I cut them out. After making a paper pattern from the plans, I taped (using double-stick tape) the patterns to the large piece of cured hard point layup material. Then, I put the metal blade in my bandsaw and cut them out. This worked real nice - the templates made it easy to cut out the right size and my metal blade (with the saw on a slow speed) cut through even 22 layers quite nicely. I used the Fein Sander to get the curved edges exactly to shape.

FuselageBulkheadsBeforeHardPoints.jpg (9314 bytes)

Here's the landing gear bulkheads, after the foam was cut and beveled, being fitted with the hard points. In the next step the hard points were glued in (using the Masking Tape tip)

Next step is the Firewall