Face landing gear mounting surface

Using the orthogonality jig, it is found the mounting surfaces of the landing gear are quite far from flat and level, certainly worse than the 0.5mm gap limit for packing the shims. That said the real requirement for the shims is only to fore-aft ensure load transfer to the main beam of the landing gear, not so much the tubes. Still, facing will simplify the sizing and installation of the shims

Another angle showing how the high point is generally towards the top side of the main beam and especially the top side tube. It is most important that the tube is not the highest profile part of the surface since fore-aft loads will be transferred to it rather than the main beam. Not a problem for the tube highlighted here by the bolt, but quite common for the top-side tubes.

Another example, not as bad.

Used the jigs to mark out limits for the facing

Using hand files, I worked on the high points and progressively reduced them continually checking with a feeler gauge. I generally got the flatness to within 0.0025-0.005" (0.12-0.24mm), and orthogonal to the bolt direction. This is a large improvement from the ~1mm profile variation and well within the 0.5mm requirement for the maximum gap when the shims are installed (prior to tightening the landing gear bolts)

Final result, RH front

Final result, LH front

Final result, LH rear

Final result, RH rear

It was evident from the toughness of the non-fibreglass region around each of the stainless steel tubes that this epoxy resin was filled with cotton flock (for strength)

LH side face-face distance 127.5mm

RH side face-face distance 126.3mm