A 24mm Engine Mount from an 18mm Mount

One of my builds required changing a 18mm mount to a 24mm engine. 

Trace around the 24mm engine tube with a sharpened pencil, centered on the ring.

Cut out the inside ring with a sharp knife, just inside the pencil line.

On the right is the cut out center above the new 24mm centering ring.

Clean up the inside of the ring with some 400 grit sandpaper wrapped around the smaller 18mm engine.

Check the fit on the 24mm engine mount tube as you go - you'll want a sliding but fairly tight fit.

I like to punch some relief areas for the engine hook and Kevlar line. If there is no allowance for the hook and Kevlar, the round shape of the motor mount tube can distort.

To be sure they are centered and on opposite sides, I draw an cross on some card stock and mark the twelve and six o'clock positions.

Using a rotary punch, some crescent holes were made. Punch out just enough for the hook and Kevlar.

On the right side picture, the upper ring has an engine hook notch (top) and a Kevlar punch (bottom). The lower ring has a crescent notch for the engine hook.