Dremel carbide tool experience

[evfreek]

Hi. Just thought I'd share an interesting experience I had with a Dremel carbide end mill. I have a touchmark that I wanted to "touch" up, and it is good and hard. So, I wondered if a Dremel moto-tool with a small carbide end mill would work. Information on the web is pretty spotty on these things, and I don't know anybody who has much experience with this technique.

This weekend, I went to a flea market, and someone sold me an as-is Dremel for $1. Worth a try, especially since I already have a broken one. There was a friendly fellow selling carbide bits for milling. There were two types available. One looked like a standard end mill. The other looked like a pointed spiked burr. He suggested the first type for cutting slots, even in hardened steel. He gave me two tips: use kerosene as a lube (not WD-40, he said it is an urban legend that WD-40 is primarily kerosene), and take it easy, since the bits are brittle. He recommended buying two, since I would break one while learning. No problem, they were 2 for $1 (used).

Since I did not have kerosene, I used WD-40 . The cutting went remarkably smoothly. I held the tool with two hands, and it was steady enough to avoid breakage. These bits cut the hardened steel fast, and cool cuttings were flying off. The main problem I had was that I couldn't see what I was doing, and made a few gouges. Even with a hi-intensity lamp and my face right up to the work, it was hard to judge angles. Also, these cutters will not cut a straight line freehand. They are mainly only good for removing small sections. Maybe some sort of jig would be useful.

The result was semi-successful. And there were no problems with feed or breakage or chatter, as the web would have led one to believe. It was all control. These things cut fast, and one slip will leave a nasty gouge that is not repairable.

I learned another thing from the seller. You can mount these tools in a handle, and use them by hand as an engraver. I tried this and, also surprisingly, it works. Just thought I'd share a bit to inject a little experience into an interesting topic.

[keykeeper]

Hope you had your PPE on. When these types of bits DO(and they WILL) break, at the high rpms generated by a "dremel" tool, the pieces become projectiles, tiny speeding bullets, if you will.

Ask me how I know.

[chyancarrek]

He EV,

I've been doing something similar using my Foredom ( higher powered Dremel type tool) and have had really good results - I bought my bits from a surplus seller also and they're remarkable handy for lots o stuff!

Key's right - keep those ol' glasses ( or shield) on because the bits do break (it's happened a couple times) and it's a zinger when the pieces come off!

[evfreek]

Hi fellas. Thanks for the safety warning. I am using a good pair of safety glasses with side shields. When I grind, I use a face shield, so that I can ignore the sparks. This process does not produce sparks, but broken pieces are definitely a worry. I'll use the face shield for this too. Probably, it is worth setting up some kind of jig, since I cannot control the tool very well. The Foredom is a big brother to the Dremel? Does it use larger shank bits? I have seen carbide burrs used with die grinders, but I don't like the cuttings that they generate.