Fabricating the Elevator!

Hello .. it has been a long time since I have updated this blog.

After joining the Facebook community, I started posting the PIK repairs there. So, it's time for me to update the blog.

As mentioned in earlier posts, the elevator was totally destroyed and not repairable. I fortunately had the elevator from Roberts PIK-20B to use as a pattern for a mold.














After making the mold, I found that the top and bottom of the elevator was symmetrical, so a making a two sided mold was not necessary.















At the time I started the fabrication of the skins, I was unable to find any drawings from the PIK website in Finland. I tried contacting them but after months of waiting, I started looking at other options. The only reference I had was the repair manual and the elevator from Robert.

The manual had the glass layup as a single ply of 92110 and 92125 on the 0 axis (running the length of the elevator).



 
I made the two skins first to see how they would mate up to each other.














After the skins were completed, a layer of 5mm PVC foam needed to be epoxied in and shaped.




After completing both the top and bottom of the elevator, it was necessary to start carving out the hinge pins and center support from the broken elevator. 










Again, using Roberts elevator as a guide, I mounted the Rose Joint Bearings to the mold in order to correctly located and position the hinge pins to match the mounts in the horizontal stabilizer. After several test fitting, the pins were epoxied in.




Just as I was about to start mating the two halves, I receive an email from the Finnish Transportation Department, notifying me that they have posted my requested drawing for the elevator on their site. After downloading the drawing, to my surprise, the glass layup was completely different from the layup in the manual!.. The drawings were specifying three layers of glass. They had an extra layer of 92125 and the two layers where laid out at 45 degrees in opposite directions.

Now I thought I was going to have to start from scratch!

After a sudden panic attack, I realized that I could verify what the original glass layup was by doing a burn test on a piece from the broken elevator. The test just requires taking a piece of the original material and burning off the paint, foam, and epoxy, just leaving the fiberglass. Simple test, and I should have done this from the start of the fabrication..

After conducting the test, I found that the there were only two layers, 92110 and 92125 on the 0 axis.  I don't know why the drawings and the production glider vary? I have seen so many variation of construction between the PIK gliders!


Now I was ready to mate the two halves together











After completing the task of joining the halves together. I let it cure for two days. The finished piece popped out of the mold and was ready for clean up. This photo shows the pattern and the finished piece













After the elevator was cleaned up, it was time to test fit it on the horizontal stabilizer.

It fit perfectly and with no restriction of motion!

The next step is to clean up the surface and then prep and paint.

Robert will do the weights and moments.

The PIK finally has a complete set of tail feathers again after 4 long years!