RV-3 Rear Spar Carrythrough Length?

[Ironflight]

Question for those who have mounted their -3B wings.....

We are getting ready to rivet up the F-305 bulkhead parts, and at this point, I have left the rear spar carrythrough bar long. We went with several folks suggestion of using a wider bar for the spar to increase edge distance when drilling the rear spar attach bolt holes, and I am one of those guys that never likes to cut anything off until I have to, so the ends are sticking out a couple of inches beyond the plans dimension. Obviously, they will have to be cut off some, but I'd like to leave them as long as possible to give edge distance on the "end" of the bar.

For those that have cut them to "plans" length and then mounted the wings, how much longer could they have been and still allowed the wing fork to fit? Can I make them an extra half inch? It will be a lot easier to cut now, before the carrythrough is riveted on, then later on....

Paul

 

[Tony Spicer]

Paul,

I did mine per the print and had no issues with edge distance. No QB wings, though.

Tony

 

[Ironflight]

Thanks Tony - I may leave them a quarter inch long - that amount I could grind off if I needed.

Paul

 

[Frank]

rear spar carry thru

Paul,
It's a function of how far the butt rib on the wing is from the fuselage (at the rear spar clevis) when the main spar is fully inserted and trued) into the wing box. Since the butt rib is perpendicular to both spars, a few right angle measurements should give you the length that will fit. I left mine a little long and had to cut a bit off. Tomorrow I will measure hole to hole and total length on the carry thru and let you know the dimensions Note: There is not alot of extra room and any carry thru length beyond minimum requirements is just extra weight.