Diamond Core Drill Suggestions?

Water jet ?

Hi Black Dragon, I've dealt with these folks:

should be able to recommend tooling for your needs. I've also used Titan Tool Supply: using some diamond pins for grinding out the remains of a ~.562 carbide drill I'd broken in a chunk of 304 (D'Oh!).

I've also made my own when I needed to drill small holes in glass or ceramics by using hypodermic needles and diamond paste.

Critical issues include proper backing to prevent "exit wounds", and keeping bonded drills flushed with water for cooling and swarf removal, or dipping fresh paste in when using a hypodermic needle. Don't get excessive with feed pressure, and play with RPM (I used about 2K and a sensitive drill chuck with needles).

The best was centering a .030 hole at a 45 degree angle through a quartz window...

Toolpost

Material is too frail, would disintegrate. Laser was tried and results were unsatisfactory.

BD:

Well, I don't know the dimensions of your honeycomb part, but if it's thin enough perhaps you could pour some cerrobend in the honeycomb cells to keep the thin walls from being crushed/torn and then test cut it by various means - finding which one imparts the least amount of damage. I personally like the waterjet suggestion.

I like that idea. A lot. But it would likely leave traces of elements in the fusible alloy on the filter once removed. That's unacceptable for the application.

BD:

I'll assume Wire EDM was one of the first considerations.

If there's such a thing as electrically conductive ceramic, Zirconia Mullite isn't it.

BD:

I thought maybe with the Zironium content it might be conductive. And at 800 degrees C it seems to be. Not much use for your purposes though, unless you could find an 800 Degree dielectric that wouldn't melt your EDM.

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Zirconia (ZrO2) is an extremely refractory material. It possesses excellent chemical inertness and corrosion resistance at temperatures well above the melting point of alumina. McDanel Zirconia is fully stabilized in the cubic crystal structure to avoid cracking and mechanical weakening during thermal cycling. In addition to its high temperature capability, Zirconia offers low thermal conductivity and is electrically conductive above 800°C. Also has the unique ability to allow oxygen ions to move freely through the crystal structure above 600°C. ========================================================

I stand corrected. Deionized molten Aluminum dielectric you say?

Actually, we found the material grinds quite easily so no need to waste time and material experimenting with other machining methods.

Black Dragon wrote in news:gq2ro9$24no$ snipped-for-privacy@bdhi.local:

Farm it out to a shop that does ultrasonic hole drilling.

It's "slugs" that are needed, not holes. Thanks for the tip though, it'll come in useful in the future. Didn't know there was such an animal.

Black Dragon wrote in news:gqcvfe$p5p$ snipped-for-privacy@bdhi.local:

I'm pretty sure they can do that too. They use diamond coated tools and high frequency vibration. Very low cutting forces.

To follow up on this, I never pursued core drilling out the slugs we needed. Instead used a coarse borazon wheel in a jig grinder. Set the finished dia of the slug and plunged the material around it away. The ideal machine for the job would be the high speed mill but it's busy.