Estes Teros Upscale, Part 4, D.I.Y. Centering Rings

I had some 50mm Quest centering rings but they were for 29mm engines. I'll have to cut my own rings from mat board for 24mm engines.

I'm using heavy walled BT-50 for the engine mount tube.
It's easier to center the circles if you draw the smaller inside one first.
I took the ring I had, centered it over the smaller circle and traced around the outside.

The inside circle is cut just inside the pencil line.

The inset picture shows the smoothing of the cut circle with 220 grit over a finger.
Test fit the inside circle over the BT-50 until a friction fit is obtained.

After the inside circle is fitted cut the outside circle.
This line is cut to the outside of the pencil line and will be sanded for a friction fit in the 50mm tube.