Chapter 18 - Step 8

This step involves installing the turtleback.

Flange vs. Hinge August 20, 2006. The next task was to set the turtleback on place on top of 1/16" thick support. The goal is to trim the trailing edge of the turtleback for a good fit against the firewall. The first issue I encountered is that the aft hinge interferes with the turtleback flange. So here you can see I have marked off the flange at the area of interference. I will cut this piece off so the turtleback sits properly. Keep in mind the interference comes from the hinge pin area of the hinge, not the flat part of the hinge.

Fitting Turtleback to Firewall August 20, 2006. Here is the turtleback resting against the firewall in a test fit. I made centerline marks at the aft end of the turtleback on the top to line it up with the center line on the firewall. I also made center line marks on the front bottom of the TB-1 bulkhead and the top of the shoulder support so I knew the turtleback was seated properly. None of this is mentioned in the plans.

Floxing Turtleback August 22, 2006. After taking a deep breath I piled a bunch of flox onto the longeron between the firewall and the future turtleback cut line. I then set the turtleback into place and adjusted it to the correct position and then clamped it in place. During test fitting I found the right side of the turtleback buldged out about 3/16" from the firewall. It didn't take much to push it into the correct position so I leaned this container full of nails and screws up against the turtleback for cure.

Floxing Turtleback to Firewall August 22, 2006. The radius of the turtleback was such that the interior curve of the turtleback was just a hair less than the outer firewall radius. I filled the "gap" with flox giving it a perfect fit.

1/16 Inch Spacers August 22, 2006. I made six little squares from 1/16" aluminum for the spacers. The aft most pair became floxed in when the turtleback was floxed in place. The front and middle pair were simply taped in place so the rest of the turtleback sat on top of them. The tape kept them from moving as I put the turtleback into place.

Floxing Turtleback to Longeron August 22, 2006. A shot of the 1/16" of flox between the longeron and the turtleback flange. I can't wait to see how much squeezed out on the inside. The clamp is where the aft 1/16" spacer is located.

Interior of Turtleback August 22, 2006. My fuselage has a true interior now - how cool is that? As best as I can tell not too much floxed has oozed out in the interior.

Trimming Turtleback Flange August 24, 2006. My interpretation of how the flange gets trimmed. Hopefully this is right. I guess most of this gets covered by a fairing in chapter 24.

Trimming Complete August 24, 2006. A closer view of the aft trimming.

October 22, 2006.