Thee main landing gear mount installation is shown on DWG 34A.
Before fitting and bolting the mount to the fuselage, the upper gear leg alignment bolt hole had to be completed. I made sure that the inside of the mount tube and the knob on upper end of the gear leg were clean and had no burrs around the holes.
I then slid the gear leg into the mount and aligned the hole.
I match drilled the leg to the mount using a 0.311” drill bit.
I removed the leg and cleaned up the burrs.
I installed the WD-721 landing gear supports to the forward side of F-704. I needed to slightly enlarge the elliptical openings for the landing gear weldments to pass through the floor as well as the flange of the main spar. I also needed to slightly adjust the angle of the WD-721 flange that mates up to the vertical leg of the lower longeron at its aft end. I also checked the fit of the forward pointing brace tube of the WD-721 weldment.
I had to open holes in the WD-721 that didn’t line up with the main spar holes. I did not drill through the spar, but marked the holes, removed the weldment and used a round file to remove just the area of interference.
I was careful to not forget the additional washer between the mount and the lower part of the spar as called out on the plans.
As there was a gap of less than 1/16” it was acceptable to pull it tight to the longeron with the bolts. If it had been more than 1/16”, I would have had to use a spacer made from aluminum scrap or rebend the brace tube slightly as required.
I drilled 3/16” diameter holes through F-770 and F-7101, 7 places per side using pre-punched holes in WD 721 as drill guides.
Time: 4 hours.
Leonard's RV-7A Build 