Centering Rings - DIY! Part 2

Here's an email tip from Brian Coyle with a better way to center the interior tube circle: 

Here's a tip to help align multiple circles when using tubes like you're doing on the blog (instead of a compass).
Draw cross hairs on the CR material.
Use a 4 fin wrap to mark the tube
Align the tube using the markings
Rinse repeat for the second circle.

Thanks Brian! I have done it this way before with great results. For whatever reason I simply "eyeballed" the interior tube and traced around it this time.

Check the fit on the motor mount tube before sanding smooth the inside diameter.
This is just a small piece of 220 grit to smooth out the rough edge.

Sand a bit, check the fit!
You'll want a friction fit on the inside tube.

I still haven't cut out the outside diameter of the ring.

The outside circle is much easier if you have good, sharp scissors.

Here again I am cutting just inside the pencil line. This line was traced from outside the mainframe tube. Of course, it needs to slide into the tube so it is cut slightly inside the line.