Wed Aug 05 2020

Fuel tank vents

First thing today was to clean out the countersunk holes and repaint. No picture of the painted part, sorry. I put it in the oven to minimize dust and pollen from falling into the wet paint.

I formed the half airfoil pattern in that block of poplar and used a piece of 1/4" rod to locate it on an aluminum bar.

The first cut with the pattern bit looks okay...

But the vibration is significant. The little collar lost it's setscrew allowing the bearing to slide up and down on the shaft.

Found the setscrew! What are the odds?!?!

I ran out of plunge travel using that little 1/4" shank top-bearing pattern bit; so I switched to a bottom-bearing pattern bit and flipped the aluminum plate over.

Okay, not terrible. I flipped everything over to cut the other half of the airfoil shape.

After flipping everything over, I started cutting the other half of the airfoil. The vibration while cutting aluminum is apparently pretty severe. The collar lost its setscrew again. Nowhere to be found this time, I'm afraid. :-( Also, you can see to the left of the cutter that one of the baseplate screws has started backing out. appears the bearing kind of burned a dent into the pattern. Although not a complete failure, I think I'm going to need to find a different approach.