Milling Epoxy Tops on a CNC

Thoughts on tooling and dust control for cutting inch-thick epoxy on a CNC router. February 12, 2010

We are going to start to cut epoxy tops on our CNC and I am wondering if anyone has done this? Iím looking for tooling. Speeds and feeds in metric Ė itís the only way to go. Any help would be great.

Forum Responses
(CNC Forum)
From contributor M:
Be a little more specific. What thickness? Does the epoxy have any filler in it? Will you be cutting through or pocketing?

From the original questioner:
Tops have no fillers just straight epoxy, it is 1" thick. We are just cutting out the sink holes.

From contributor M:
At a former employer we did a lot of what you are describing. The tools we used did not look like your typical router tools. Picture a straight tool shaft of 1/2" diameter (or your own preference) with no flutes, but instead it has diamond chips impregnated to the side of the shaft (think of a spindle sander), and this (now) diamond abrasive is what does the cutting action. The only caveat to this is that you must pre-drill a penetration hole for the cutter.

These were custom made tools and we actually had a couple different diameter's, but they were awesome for cutting the epoxy. The downside was the dust. If your machine can deal with it use a water bath for cutting to keep the dust down. Otherwise have good dust extraction. The cut dust is just as nasty as the raw powder prior to molding.

From contributor P:
I bought this cuter to cut epoxy but was never able to use it as the customer changed material at the last minute but this was the bit recommend buy my tooling supplier. Just to make sure I called him back to get some clarification if this was the right bit. He said it was. The rep said that this bit would work just fine but recommended using the 1-1 over the 4-4. My tool supplier did say however that they have tweaked the 4-4 design and that he is getting mixed feedback from other guys that use this same bit.

Some guys love them and some are not all that impressed but he did not give me any feedback on why people had such a different opinion on this bit. The tooling supplier is a very reputable shop that sharpens and sales router bits for a living. He has probably forgotten more about bits than most people will ever know and he has never sold me anything in the past that did not work. He also sales to the majority of shops in my area that run CNC.