Dremel hack to make a better router

I've been cutting ABS plastic with a crappy Dremel rotary tool and the result was less than spectacular. The cuts were not very smooth and the width of the cut was slightly wider than the router bit due to the vibration of the bit which seemed rather dangerous in that it could possibly catch against a harder material and fracture. While these issues can be minimized by playing with the rotational speed of the bit and feed rate of the material, they are still present.

I'm not sure the model of the Dremel matters, but if you take the thing apart, you might find that the rear-most bearing on the motor shaft sits inside a soft rubber bushing and this is what causes the cutting bit to wobble and produce crappy cuts when routing.

I don't know the reason for the rubber bushing, but i eliminated the thing and took up the gap using aluminium foil tape, though just plain aluminium foil, or any other metal shim material, should work. If you do this, make sure you're very careful to add just enough shim material to take up the space left by the removal of the bushing. If you fire-up the tool and it doesn't sound right, you may have used too much.

The result is dramatic; cuts are now much smoother, more accurate, and the vibration is gone. How this may affect the tool's life remains to be seen.

Lesson learned: don't by a Dremel next time.