Thank you.. I thought that was the correct location of the CG but wanted to be sure.

I installed my retracts on the weekend, the mains were pretty straight forward, I did change to the first hole on the control horn so that the secondary doors open a bit more than 90 deg and I added a little brass tab so that when the doors are closed they stay in alignment. The tail wheel was a lot more difficult.. needed considerable modifications to work properly. I added a 1/8" x 1/8" stiffner along the leading edge of each door half and made small blocks that I bonded to the inner body to give the hinges some thing to mount to.

The doors still tend to catch the wheel just before it clears as it closes so I believe the answer is to increase the veritcal hieght of the sides on the aluminum bracket that mounts to the retractable tail wheel assembly so the doors close a little later. I am trying to find some very, very light springs to replace the elastic bands with but no luck so far. I also installed some small eye hooks at the point where the elastic band attaches to the doors so that the doors do not go over center and hang up.

I had to add a second air tank as the single one from Robart does not have enough capacity to cyle the doors more than 4 times. I get about 10 good cycles now. I made some gaskets from some dense foam I had (it was the packing from a Saito engine box) that I made donuts from and glued to the air tank mounting points .. this makes a friction fit for the tanks as they slide in and a small shot of flexible CA hold the tank into place. This allow the tanks to slide much further toward the nose and simplifies attachement. As designed the tanks had no bearing at the head due to interference from the servos for the air valve and the throttle.