Using a Dremel on a lathe

[prasad]

Guys,

I recently made a Dremel tool holder and I tried to use it as a grinder. I see two possibilities. I am not sure which one will be the best.

1. Mount the Dremel on the tool post, adjust the compound to the necessary angle and then feed the Dremel tool forward (away from the operator) just as you would if it was a regular cutting tool.

2. Mount the Dremel tool and place it behind the part being machined and bring Dremel towards you (towards operator).

Thanks
Prasad
Wynnewood PA

 

[Andre]

Both are incorrect. When toolpost grinding you want the grinding wheel grinding against the material, not rolling on it. Run your lathe in reverse, and point the dremel towards the lathe headstock. The work and grinding wheel should be moving in opposite directions.

 

[Bill Gruby]

Andre is correct, you want the wheel turning against the rotation of the work piece. The Dremel mounts wheel facing the chuck. The spindle on a Dremel runs CCW as you are looking at the wheel end. When this is mounted it will run with the chuck with the lathe running normal. You must reverse the chuck direction to grind material off.

"Billy G"

 

[george wilson]

A Dremel tool is a VERY poor substitute for a tool post grinder. Their bearings are not even properly seated in their mountings.

You can improve the performance of the Dremel tool by taking the housing in 2 pieces,and exposing the bearings in their seats. Proceed to fill up the empty spaces in the bearing seats with Bondo or J.B. Weld. Be careful to NOT get the filler material onto the side surfaces of the bearings(The shields). You do not want to freeze the bearings up.

Filling up the gaps around the bearings will help a great deal to improve the surfaces you can produce when trying to grind with the Dremel tool. However,the basic quality of the bearings is not the best. High tolerance bearings cost a lot of money. Much more than the Dremel cost.

I have a 1/10 H.P. DUMORE hand held grinder,which is VASTLY better than a Dremel,if you can afford one,or can find a used one that still runs well(meaning the brushes have not gotten so short they overheat the commutator). Brushes can be replaced. Hopefully,there will not be a groove worn into the commutator,though. This can be determined only by taking the grinder apart.

I would submit that a small router,like a Zip Cut(Is that the name?) drywall router,would be a better performer than the Dremel.

Dremels also have a weak plastic connector that connects the armature to the chuck. It has the habit of easily failing at the slightest provocation. Or so it seems. I gave up using a Dremel,and use an old Dumore or an old Fairchild hand grinder I got at a flea market.

 

[Rick Leslie]

My old Southbend will nt run in reverse as currently set up. Consequently, I am forced to grind 'incorrectly'. I can still achieve satisfactory results by running the lathe spindle very slowly and using my little Dumore Tool Post Grinder (30,000 RPM rated). If you must use a Dremel, I would take the tiniest of cuts possible (barely spark off) and set up as in figure 1 (grinder in front of work). This will throw the debris down. The other way will throw grinding dust into the air. Be sure to cover you ways well.

Bear in mind that this is still the incorrect and least desirable way to grind, but if you must, you must.

 

[Fabrickator]

A Foredom also works better than a Dremel being of higher quality w/ an all metal body and 3-jaw chuck. Here's mine is set-up on a ball turning jig for a special application with a std. 1/2" tool holder.

 

[darkzero]

Seems like people use Dremels with success, mainly the mini lathe guys. I tried a Dremel mounted in the tool post with one of those holders that screw onto the nose of the Dremel. I never got good results but maybe I was doing it wrong.

As said the Dremels don't have precision bearings & the bearing seats aren't that great. The plastic housing flexes as well, especially where the nose threads are. That's not to say it can't be done though as it has.

I was going to use an electric die grinder with a metal housing or one of those pencil air grinders. Better than a Dremel that's for sure. I ended up scoring a Dumore tool post grinder for cheap. It's their smallest model but it's way better than a rotary tool.

 

[george wilson]

Back in the 70's there was an article in Fine Woodworking about improving the Dremel's performance by packing the bearing housings snugly. It made a big difference.

 

[Andre]

You should really use a air pencil grinder, they are 100x better than dremels. And that don't have that gyroscopic affect dremels have either.

They are faster, more accurate, collets are better, and actually quieter. Their cheaper too! Mine was $30 with in line lubricator and air chuck quick connect.

 

[george wilson]

Agreed on the pencil grinder. Get a small one unless you have a LARRRRRGE air compressor.