Epoxy slab flattening bit

[blackhawk]

Does anyone that uses their CNC to flatten epoxy slabs have a good recommendation for an insert cutter. Right now I have one that uses two carbide inserts and is 1-3/8" diameter. I run it on my CNC with a Porter Cable 7518 router. I have trouble with tearout when flattening epoxy slabs unless I keep the passes to .010" deep or less which takes forever. I would like to step up in diameter and have a cutter that prevents the tearout. If you have direct experience with a good cutter for epoxy, please let me know.

 

[Chaz]

Does anyone that uses their CNC to flatten epoxy slabs have a good recommendation for an insert cutter. Right now I have one that uses two carbide inserts and is 1-3/8" diameter. I run it on my CNC with a Porter Cable 7518 router. I have trouble with tearout when flattening epoxy slabs unless I keep the passes to .010" deep or less which takes forever. I would like to step up in diameter and have a cutter that prevents the tearout. If you have direct experience with a good cutter for epoxy, please let me know.

Inmmy experience, the best solution to epoxy tearout, is to keep in mind that it doesn't like to be forced. So, if .010 offers the the best performance, then that's what you have to do. I do a lot woodturning with epoxies - acrylic, etc. . To move quickly a shearing cut is best. Some facing tools work more like scrapers, which is fine for wood, but expoxies, like I said, need a gentler touch.

I use something like this:

If you want isert cutters, you may consider this:

It's designed to present a negative rake to the surface and won't be as aggressive. It could work better than your current solution. The downside is that it's $180.

 

[blackhawk]

Thanks for the info.

 

[JBowlin]

Im using the 1 1/4" version from spetool with inserts and so far I like it. It has surfaced more MDF than epoxy so far but the epoxy I surfaced last week it did great. I normally do fairly light passes but at 400ipm

 

[Dee2]

KWS has an insert cutter that I've used for pecan cookies. Nice, IMHO.

 

[Echd]

I haven't had any major issues with Carbide insert cutters. I use a 3 inch spetool for larger surfacing jobs and it has done fine.

RIP Precision Tools sells a line of insert cutters that take negative rake inserts. Possibly worth consideration but honestly I'd rather just go a little slower and shallower and save the money.

 

[Oka]

I have the 2nd one 2.25" I like the carbide insert because it cuts really clean. I found you just hog down on 1st pass and then take a light minimum pass 2nd time to make the finish nice.

It may be expensive out of the gate buy once-cry once but the inserts are cheap and it will be the last bit you will need for this type of work.