Lakeroadster's Fin Alignment Fixture

Inspired by this thread Homemade Fin Alignment Guide I decided to take a crack at making a fin alignment guide.

My design is basically the same as The Rocketry Forum's @qquake2k with the exception of being double sided. One Side is for BT-60 thru T-400 tubes, the other is for BT-20 thru BT-55 tubes.

Here's the CAD drawings:

 2024-09-16

Armed with the drawings I headed out to the barn to make some sawdust. I changed the design a bit, making 4 longer legs for the base.

I mocked up the parts for a visual representation... once the glue dries and I get a couple carriage bolts, I'll post up some more photos.

2024-09-17

Here's the finished jig / fixture.

I ended up using 3/8" dia. x 3-1/2" Carriage Bolts, washers and wing nuts. The wing nuts were $2.48 each?

For the mock up photos l used a piece of BT-60 and a left over plywood fin from my Spad Ace build, and that's a BT-50H for the smaller tube.