Which bits are the most useful for rmodelling? Mostly for sanding & cutting and also for drilling out sleeves and that do less damage to the model.

It really depends on what specifically you want to do. I'v probbably got close to 200 Dremel bits.

Matt

I have a real small cutting bit that I use to make weld marks. You can hardly see the tip on it but it works pretty well. As far as sanding you will probably have to get the get the regulator that slows things WAY down. If not it will pretty much just melt things and do that very quickly. I am thinking of trying to buff the glass on my Avenger but its a real powerful tool when used with models, I am affraid to do more damage than good.

I find myself using two types of bits most frequently: 1) tiny engraving bits with cutting edges, and 2) small diamond-coated bits. The engraving bits are sold by Dremel and are fairly expensive, but they should last forever on plastic. The diamond-coated bits I buy at Harbor Freight when they're on sale. I also use the floppy, cloth polishing disks and the rubberized grit disks for cleaning up rough spots (at low speeds ONLY to avoid damaging the plastic).

The most important thing in plastic machining is speed/torque control. I like to use a battery-powered Dremel with a slightly depleted battery, since it is less likely to melt the plastic. On a big Dremel, be careful not to leave the bits in any one spot long enough to develop heat and melt the plastic. Also, watch out for tool "kick-back." On metal or wood a stray bounce of the bit can be ignored. On an expensive soft-plastic model it can be heart-breaking!

-Neil