can someone confirm datum line

[Matthewtanner 44]

i'm doing some calcs, and can't remember if the tail dragger avid c main axles are 1.5" -ish aft the 0 datum, or forward.

Edited 11 Apr 2019 by Matthewtanner

[1avidflyer 1983]

Definatly forward on the ones I've measured.  I seem to remember 3/4" forward.  JImChuk

[nlappos 413]

My records show for original Avid tail dragger gear,  -1.6" for main axles, which is forward of the wing leading edge (the datum). 

[Matthewtanner 44]

yikes, i've been flying with it forward of cg...for some reason i seemed to remember when i leveled out the aircraft, the axle was behind 1.5"....at least i know it flies ok forward of cg.

[akflyer 1427]

move your CG back to 16" or 18" and you will be shocked how much better it flys...

[Matthewtanner 44]

yea, now i'm gonna try to find where i can source lead shot locally to make a weight bag. i was flying around at 11.2 cg because i didn't minus the moments of the front wheel weight, i added them.

[Matthewtanner 44]

not that it's gospel...but on the manual page 1-9 the example for the nose gear is "-" but the tail dragger the mains are "+". I could travel back out to the hangar and just level out the aircraft and drop a plumb line, but the manual plus i just for some reason remember the axles being behind....but really it doesn't make sense that they would be.

[Matthewtanner 44]

I couldn’t take it boys....had to go do just that. My axle behind leading edge, which means my cg a-ok