Originally posted by rajul
I think they should redesign the firewall and LG first. Sadly nothing was done for the UCD40 although they are aware of the issue. I have a UCD90 and had to do a fair bit of reinforcement. Wonder who runs the engineering dept at Great Pains uumm ...err..Great Planes ??
I have had problems with the LG and Firewall on my UCD. The landing gear fell off after a few flights while I was taxiing back to the pits. I laminated two peices of 3/16 ply together with epoxy to make a new LG block (the old one broke during a "Small" crash...it was the second time the LG came off) I also added tri-stock to the front and back sides of the new lg block and epoxied the whole assembly in place. I wish I had pictures becasue it would be so much easier to show than describe what I did next. I drilled two holes that went through the wing dowel plate on the fuse, the LG block and then throuch a balsa truss I epoxied up in front of the LG block and inserted two peices of carbon fiber tubing for reinforcment. Has been competly bulletproof so far.
The firewall came out on the same crash the LG did. I found the firewall was held in with pretty much nothing and probably would have pulled itself off from fatigue after enough flights. To reinstall and reinforce the firewall, I cut up some 1/2" tri stock and epoxied them up in an upside-down "U" shape along the sides and top of the firewall. To plug the gaps I used CA to glue in 1/16" small strips of balsa in between the gaps then sanded them flush to get an uninterupted "U" shaped rib to butt-up agains the fuse sides and upper stringers. Epoxied the assembly in and I dont think it will ever come out now. The fuse would break first I'm sure.
I don't know how you would go about accessing the firewall from inside the plane, but it wouldnt take much just to pull out the firewall. I think maybe if you used a heat gun to head up the glue holding it on, you may, with a bit of force, be able to "rip" the fuse out and make your custom reinforcement for it. Better now than to watch your engine fly off after a couple hundred flights or so. I know it's possible...I watched one guy with his ARF (not a U-Can-Do) on the run-in stand one day and the power from the engine pulled the firewall right out. The plane had never flown!
For all you U-Can-Do owners out there, I consider reinforcing the LG and the firewall a MUST for your and others safety and longevity of the aircraft.
If you don't have a U-Can-Do yet, I have a very in depth review posted in the product reviews section on this site if you want to check it out.
Click here to go to my review of the UCD3D]