birdus
Well-Known Member
I'm building a Super Baby Great Lakes. There are small aluminum brackets which get bolted to the inside surfaces of the two spars. The compression tubes go between these two brackets. Additionally, the drag wires attach to steel fittings which are bolted to these brackets. So, the bolt goes through the steel fitting, the aluminum bracket, then through the spar. The two drag wires which pull in opposite directions, so the force exerted by the drag wires tugs on the bolts, so the primary force is exerted by the bolts on the aluminum bracket.
My question is this: since the force is transmitted primarily to the aluminum bracket by the bolts, how much does a little slop in the holes through the spar matter? If it is absolutely critical that the bolt fit perfectly through the holes in the spar, is a bushing acceptable? The bolts are 1/4". The holes are already drilled and reamed through lots of brackets and fittings. In fact, I would say there's not enough meat left on the steel drag wire fittings to drill them bigger. Would a 3/8" bushing be acceptable? If so, what material?
Here's a picture from the plans.
Thanks,
Jay
My question is this: since the force is transmitted primarily to the aluminum bracket by the bolts, how much does a little slop in the holes through the spar matter? If it is absolutely critical that the bolt fit perfectly through the holes in the spar, is a bushing acceptable? The bolts are 1/4". The holes are already drilled and reamed through lots of brackets and fittings. In fact, I would say there's not enough meat left on the steel drag wire fittings to drill them bigger. Would a 3/8" bushing be acceptable? If so, what material?
Here's a picture from the plans.
Thanks,
Jay