> Matt Quimby wrote: > >>> I?vegot my wing spars aligned and attached my wing attach fittings. The next > step, according to my plans, is to ream the inboard-to-outboard fitting > holes from 3/16" to ??. This being obviously a pretty critical step to > get right, I?m looking for some input on how some other folks > accomplished this task successfully (or, conversely, what methods caused > problems.>>
> Mark Langford wrote: > I think there's been a misunderstanding somewhere. The 3/16" holes are > used where #10 (3/16) bolts hold the WAFs to the spar caps on all WAFs. > The only reaming that is done (and it's not always necessary) is at > the WAF fitting bolt holes where inboard and outboard WAFs connect > together. The reaming is to enable a bolt to fit through the hole > because they are often undersize to make sure it's a very tight hole > with no slop. Another part of this is that even AN bolts are not all > exactly the same diameter, so the purists would buy several reamers > .001" apart and shoot for perfection. Mainly you just want a round hole > that's a tight fit, and a drill bit really can't get you there (their > holes are somewhat triangular when drilled in thin material). More than > likely the WAFs were either machined or laser cut, to the holes are > already round, but perhaps slightly undersize due to coatings or burrs > (laser cutting). I'd measure your bolt diameters and order a reamer > from McMaster Carr that fits them. More than likely though, a plain > 3/8" reamer will be "close enough". See > http://www.mcmaster.com/#reamers/=ypf185 and look for the "decimal > sizes" about a third of the way down. I understand the only holes that need reaming are where the inboard and outboard WAFs connect? I bought this KR2 with the boat semi-finished, and the PO had already installed the inboard WAFs and begun the foam and fiberglass work. He had drilled the WAF to WAF holes at 3/16. I assumed (bad move!) this was standard, and that this was in order to make the connection very precise before drilling the holes to the final size. Therefore, I now have my front and rear spars aligned, attached, and ready to be foamed and fiberglassed? with a 3/16? bolt connecting my WAFs instead of ??. I suppose my only recourse is careful, careful drilling. And then reaming.
