Estes Star Speeder #1366 Build, Part 3, Cutting Centering Rings

The outside of the ring can be cut with scissors if they are very sharp. Any rough edges are cleaned up in the next step.

Again, cut just inside the pencil line.

I cut four rings, only two will be needed on the model.

Stack all four on a BT-20 tube.
Sand the rough edges smooth and size to friction fit inside the BT-55.

An engine hook recess is punched in the rear ring.

TIP: Line up the rotary punch and apply a light pressure to make a small impression. This gives you a chance to check the centering of the hole before making the final punch. If it is good, use full pressure to punch through the ring.

Here's a good fit of the 20/55 offset ring in the front of the BT-55 tube.