dremel motors?

[Jules Richardson]

JOOI, is there anything special about the motors used in dremel tools (or look-a-likes)? Do they normally have any kind of gearbox between the motor and chuck, or are they directly coupled?

One of my projects is to build myself a little CNC mill (for cutting/ shaping wood, not metal), and I was going to buy a dremel tool for the business end of it - but TBH I can't* think of any reason for owning a dremel except for this specific application, so it's a bit of a waste if I can source a suitable motor at a fraction of the cost.

• well, I'd probably find uses - but nothing that I can't do well enough with other tools already.

cheers

Jules

[NT]

direct coupled, high speed. As you say, 33,000rpm motors are far cheaper than dremel brand die grinders.

NT

[The Natural Philosopher]

direct.

yes.

in fact people are throwing away old model aircraft BRUSHED electric motors.

So there are lots available.

RC car motors are probably the best bet..replaceable brushes and quite well made and powerful.

[Jim Hawkins]

I use mine with a small grinding bit to trim my toenails. The tiny little grinders the cosmetic firms sell for this purpose are utterly useless, but the Dremel is first rate!

Jim Hawkins

[Andy Dingley]

Both. Cordless drills use epicyclic gearboxes, high-torque mains drills don't (sometimes a simple spur gear reduction if they're two speed). "Dremels" are either direct drive for the fast / mains ones, or epicyclic gearboxes for (some of) the lightweight battery ones.

You can't mill wood, you rout it. This needs higher speeds. Most metals (aluminium, brasss, silver) used for hobby CNC are also routed at high speed with small carbide burrs. Unless you have particularly high torque leadscrew drive, you can't make a CNC mill that handles the forces of real milling cutters.

The usual choice is either a cheap Proxxon mill with steppers added and the original head, or else a slightly heftier mill converted by the addition of a router head. Kress is a popular choice (web order from Germany, now that Wickes have stopped selling them).

For a few foot sqiuare MDF / plywood profiler, (cheap to build, with an MDF frame) the favoured cutter head is the small blue Bosch 1/4" router.

[Jules Richardson]

Ahh, I don' think any of my local sheds even sell the battery ones (and mains would be more practical in this situation anyway). If I go searching for an equivalent motor only, I'm just not sure what to be looking for at present.

Yes, good point ;-)

Yes, that's the kind of thing I'm needing - nothing more heavy duty than that. I'm not sure if the steppers that I have are up to the job yet, though (hopefully I'll get chance to test them later today).

cheers

Jules

[The Natural Philosopher]

The model boys make CNC stepper driven dremel type routers for cutting balsa and thin ply, using 2-3mm cutters.

I agree for anything approaching 'timber' you need a proper router.

[Andy Dingley]

There are two specs for steppers: either leadscrew drive or belt drive. One needs speed (and some torque), the other needs a _lot_ of torque.

[Jules Richardson]

Yes, 1/4" ply would be the main material (rarely something thicker, which I could probably do in two passes with some manual finishing afterwards)

The motor problem might have solved itself - I spotted that there's a dremel clone on sale in a local shed earlier for $10 (which must be around 6 or 7 quid). At that price I may as well just buy one and ditch the case. Unfortunately I won't make it into town until Tuesday - hopefully they still have some left then.

[Jules Richardson]

Sadly all the ones I've harvested from things are unipolars and not particularly meaty ones at that - if I pick up one of the rotary tools (mentioned in a reply to TNP) then I can try simply hooking them up and see if they're good enough to deal with thin ply (I do have some suitable gearing to play with)

cheers

Jules

[Grimly Curmudgeon]

Indeed; the podiatrist I visited recently whipped out a Dremel-alike and ground my toenails with vigour. Quite surprised me.