Cutting motor casing

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Well-Known Member
Jan 18, 2009
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Is there a way to cut an 18 mm spent motor casing to make thrust rings? With a razor saw?
I've used razor saws and i've also used a fine tooth 4" table saw (dremel) with great success.

DO NOT use a band saw!

The wound paper or the fuel residue seems to mess up the blade.

I think it's the paper it seems to remove the "set" in the blade.

They will quickly ruin a $9 blade!
I have used a razor saw with pretty good results. If you want to make thrust rings, remember that you can peel a few layers off the inside to make it a teeny bit lighter (works best to do this after you cut it from the rest of the case).
Also, sometimes a 1/4 inch length of motor case comes out kind of limp and mis-shapen after being cut. Mush it back into the proper shape, roll the inside surface with a dowel to press the paper back together, and use a few drops of CA to 'rebuild' the ring.
One more- because the motor case nominal OD is so much smaller than the ID of BT20 tubing, I usually cut a narrow strip of paper to glue around the outside of the case. It doesn't take much and you can get a good snug fit with your new thrust rings.