Landing Gear Setting

1/17/2010

Throughout the build, we builder's occasionally come across one of those monumental days where a milestone comes to pass. Yesterday was one of those days: I got the wheels, tires, pant brackets and brakes on the gear legs, then dropped the fuselage on to the wheels. I suddenly realized I had reached a milestone...the darn thing was self supporting, on its gear! Sure, lots of removals to come, but it was still a cool moment.

Before I could get to that point, I had to get the legs back in the engine mount sockets after it came back from finish welding. Ugh. I knew there would be movement from the welding, and I expected to have to re-ream the sockets, but I wasn't expecting it taking me 5 hours! Hand reaming something this big (1.480 hole) is not fun. Although it did give me a beneficial cardio workout [lost 30 pounds, so far].

Talking of cardio...16 x 80 pound cement bags had to be loaded on to the plane in order to simulate the desired gear leg squat for the alignment process. I scratched my head for a while determining the optimum load distribution, then decided to add 40 on the turtledeck, 240 over the pilots seat, and the rest over the gear legs. I borrowed racing car scales from the EAA chapter, I greased two steel plates, placed them on the scale sensor pads then lowered the wheels on them. The grease plates slide, thus allowing the gear to squat, fully. I had decided upon a common weight configuration of 1600 pounds (solo, tank o' gas) for optimum gear alignment.

The weight was on, the gear squatted, now the moment of truth... camber and toe condition...

Using the wheel cover plate screw holes, I attached 4ft angle aluminum extrusions for the alignment process.

Unladen, the gear was toe-out with positive camber, laden, the gear is still toe-out [3 inches over 4ft] with very slight positive camber. My next task is to rotate the legs to adjust to neutral toe, this action will also add a little more positive camber, which is what I want. Rotating the legs isn't going to be easy...I have to remove the locating bolt from the socket, but the leg will then force its way through due to the weight [I have to keep the weight on for the squat/alignment], so I plan to make a box section bar to clamp over the socket tops, which will allow me to rotate the legs, sans bolts.