Dimond Crusted Bits?

[voltsandbolts]

Has anyone been using bits like this? Have you had any success? I picked these up for $5 for the set of 20 I am primarily interested in the pointed ones for engraving.

RobWms

[Litografa]

Is it for manual engraving?

[voltsandbolts]

No. I plan to try them on my jgro.

[Cruiser]

I have a set that I use with my high speed die grinder, which does 65,000 rpm. I have used them for grinding carbide and other very hard metals. They won't take much pressure, just let them cruise at there own pase and they last for quite a while. A repeat job that I do with them is sharpening my chain saw.

[Litografa]

Jgro - what is it?

[bsdphk]

Originally Posted by Cruiser I have a set that I use with my high speed die grinder,[...]

Does bits like these need liquid cooling, or can you run them dry ?

Poul-Henning

[voltsandbolts]

Originally Posted by Litografa Jgro - what is it?

Look here--> http://www.cnczone.com/forums/jgro_router_table_design/

[voltsandbolts]

Originally Posted by bsdphk Does bits like these need liquid cooling, or can you run them dry ? Poul-Henning

I believe you can run them dry but cooling them wont hurt.

[diecutter]

They last way longer if you use lubricant since diamond is heat sensitive. I use stoning oil, but any clear (so you can see what you are doing) oil can be used. As mentioned, don't use much pressure. These burrs don't work well in cnc machines and are mainly used for hand work with a high rpm hand piece, the higher the better. Some run at 100,000 rpm.

[seniormachinist]

I'm pretty sure these aren't diamond, but cubic boron nitride. I've seen them used on composite materials such as fiberglass, kevlar/Epoxy and graphite epoxy. They should be used with coolant if at all possible, and care should be taken to minimize exposure to the dust they throw off.

SM

[voltsandbolts]

Well the packaging did say “Diamond” but for 5 bucks who knows. Sounds like using theme in the CNC is a bad idea, so in the Dremel box they go for now. Thanks for the info guys.

RobWms

[diecutter]

What type of engraving are you doing and what material are you cutting into? The cutter that works best is determined by these factors; ie., v bits for v carving, ball end for 3-d figures, end mills for area clearance.

Just remember on those diamond bits, plenty of rpm, a light and slow feed, and a couple drops of light oil lubrication from time to time. I just shipped a steel ingot die where I cut the crossed keys detail freehand with diamond bits in a Foredom flex tool. Turned out pretty decent.