Different modifications, different leveling points, different CG results. Ultimately, that's why we do phase 1 testing.
You ought to have a set of the Northland PA-18 drawings which are available in the Super Cub Store: https://store.straight-level.comMy main problem is that the TC calls out the PK screw and center punch which I won't have on an experimental build and I don't know whether that is plumb to the structure or not. If I can't find out between now and in the long future when I need to do it, I'll probably just assume it is and level of the structure like you suggest. Wayne
Is your gear going to be swept forward or is it just a different length? If just a different length, the measurement should still be 2".I am truly embarrassed that I didn't think to look at the drawings. Good grief. Thanks much. Also, nice catch on the TC and the moment arm of the axles, although I won't have standard gear. .
Wayne
Something to look at when you get the kit.Truth is, I don't know. Like I said, I'm pretty new to super cubs. I ordered 3" extended but I don't know the geometry of that gear.
Wayne
There are several places which should be level or plumb according to the drawings. Due to the construction process, welding etc those locations may not be accurate. On a PA-18, the 2" aft of the leading edge for the main (unmodified) axle is the best starting point. If the fuselage is built in an accurate fixture, the firewall locations will be correct. Not necessarily the vertical tubes, but the firewall between the engine mount fittings. I recently did some work on a Bearhawk Patrol which has the lower longeron listed on the drawing as the leveling location. Due to large welded clusters at each end of the tube, there was no place which was accurate. Another place which was correct was located.I thought the tubing along the throttles was level? May have been told that.
Gary
Piper drawing shows a horizontal reference line dimensioned from the fuselage references - engine mount holes in front and a distance from lower longeron at tailpost. I'll try to find the dwg tomorrow. I have the one for PA-12, but not doubt it's in the supercubproject.com drawings somewhere also.