20041118-allegro-08-finishedtubes:
Here are my finished first-run tubes. A couple things I did wrong here:
1. The glass wasn't rolled at 45 degree angle! This increases the strength of the tube considerably.
2. When I wrapped the joiner bar/mylar/glass/mylar mandrel sandwich in thin cork, I didn't "spiral wrap" it like Drela says to. This caused a "lip" to form where I had started to wrap the layup! It could probably be sanded out, but I'm going to make another set.
Note that the tubes together weigh 4 grams. The brass tubes weight approximately 12g!
20041118-allegro-08-finishedtubes:
Here are my finished first-run tubes. A couple things I did wrong here:
1. The glass wasn't rolled at 45 degree angle! This increases the strength of the tube considerably.
2. When I wrapped the joiner bar/mylar/glass/mylar mandrel sandwich in thin cork, I didn't "spiral wrap" it like Drela says to. This caused a "lip" to form where I had started to wrap the layup! It could probably be sanded out, but I'm going to make another set.
Note that the tubes together weigh 4 grams. The brass tubes weight approximately 12g!