Blowout on laminated ply

[ADRae13]

I'm trying to cut 2" diameter holes into planks of laminated 3/4" plywood. The issue I'm having is that at the point where the cut ends and the waste material breaks away is causing a little chip in the laminate on the good material. I've tried using 1/2" bit and 1/4" bit and adjusting the feeds speeds and plunge rates and I just can't get it to leave a clean cut. I can't use tabs in this situation.

Any ideas/suggestions?

[Kyle Stapleton]

With the limited information you provided it sounds to me like you need a compression bit.

[bleeth]

This could also be due to the nature of the veneer surface or the plywood itself. Birch is almost impossible to not have some chip out, for example.
There are many qualities of veneer plywood. Domestic on poplar core will have one result and import on who knows what will have another.
To get specific answers you will need to be more specific about what tools and material and cutting strategy you are using.

[dlcw]

Stuff this small I tend to do pockets instead of cutting a hole. You don't have that piece of waste rattling in there when you complete the cut.

If you use a compression bit, make sure you plunge about .25" prior to starting your ramping. If you don't the upcut spiral on the bottom of the bit will cause a lot of splintering in the veneer. I use a 3/8" compression when making pockets this big.

3IPS at 9K RPM. I don't feed at high speed since the machine can never get up to speed going around in circles anyway. Since going so slow, I slow down the spindle so the bit doesn't scream at me because it is hungry for wood.

I use this technique in Aspire as well as eCabinets/SBLink.

As Dave said, quality of plywood makes a HUGE difference. I gave up cutting any imported plywood because the veneer is getting to be almost micro thin. It chips if you sneeze on it. Plus the adhesives being used don't seem to hold the veneer in place let alone the internal core together. So American made plywood all the way when it comes to projects in my shop.