Today I worked on reaming the spar hinge blocks. I did this per the manual’s instructions1 and clamped the hinge blocks between a couple pieces of scrap wood on the workbench so that I could focus on keeping the reamer nice and straight.
Hinge block ready for reaming
I started with the #1 5/16” hole on the end and passed the reamer through the hole before chucking in my cordless drill, as specified. I also used some liquid Boelube on the reamer. After reaming and deburring these holes on both hinge blocks, I performed the same procedure for the 1/4” holes on the other end of each block (using the 1/4” reamer but otherwise keeping the procedure the same).
The next step would have been to ream the corresponding holes in the spars so that everything could be temporarily attached and the rest of the holes could be reamed as an assembly. Before doing this, I test fit a bolt in each of the holes I had already reamed. There was a little play in each hole but especially in the 5/16” holes. It’s nothing major (probably only a few degrees of deflection) but since the manual does specify that the fit should be quite “snug” I wanted to check with CubCrafters to ensure that this is okay before proceeding.
Play in the bolt
My best guess as to the source of this play is that the chuck on my drill wobbles a bit and created a bit of extra motion. The good news is that, if this is a problem, the spars haven’t been reamed yet and the hinge blocks are much easier to replace. I’m planning on calling CubCrafters in the morning to get some resolution on this so that I can either proceed or get some replacements and address my equipment/technique.
Wing Manual (Extended Fuel), CCEX-004 Rev. 2.02, Pages 40-41 ↩