[sreinmann]

I rediscovered interesting tip tonight that I hadn't fully appreciated before. Among my hobby files is a steel needle file which tapers from 3mm down to 1mm. It's come in handy in a number of interesting ways. For one the serations grip the back side of the paper when rolling curves and cylinders. Next - and most useful - when forming a cylinder to its final diameter, you can ease up and back down by twisting the file before glueing in place. Then a quick twist and your able to back the part off.

I don't know if the pictures do the description justice. But if you've struggled with tiny cylinders and especially getting them to be just the right diameter, you might give this a shot.