Bit Life in High Pressure Laminate

How many sheets should you be able to cut before a bit wears out? Comparing carbide with diamond, and a discussion of feed rates and settings. July 3, 2005

Can someone suggest spindle speed feed rates for cutting HPL (Pine PB Core)? Tooling? We have been using an Onsrud 163MW at 16,000RPM and a feed rate of 16M/M. We are only getting about 10 sheets per cutter before the cut quality degrades severely.

Forum Responses
(CNC Forum)
From contributor G:
HPL does destroy a cutting edge. We suggest using a 3+3 tooth design and reducing your RPM's or increasing your feed speed. What is the thickness of your material? As the 163 is 7/8" LC, if you are machining 3/4" and the board is not 100% flat, you may be cutting with no cutting edge.

From contributor S:
Try diamond compression bits. I cut a lot of 1" board with HPL on one side, and backer the on other. I get well over 200 pieces out of a cutter before sharpening. I run at 6 meters per minute at 22,000 rpm. Tooling guys will tell you to run faster, but my experience is that it will cause problems.

From the original questioner:
Contributor S, what cutter exactly are you running? That yield sounds high, but that would be great to get even 50!

From contributor T:
We use a 1/2 compression diamond bit for laminate on MDF or PB. I ran a job of 200 + sheets, and when I was done you couldn't even tell which part of the tool cut all the laminate. (Not like carbide where you see a groove in the cutter after not very many sheets.) I was very impressed by diamond tooling. Definitely worth the money.

From contributor G:
The PCD tool is a great alternative, but you gain on tool life what you lose on productivity. If you are not running a high production and if you are machining small parts with the PCD, it is great. If you are running production with our 1/2" tool feed, speeds should be around 20-25 MPM. 5-7 MPM at 18,000 rpm's is what we recommend.

From contributor G:
What does a diamond bit go for? I was told $1500 at 200 sheets = $7.50 a sheet. Carbide is $35 at 20 sheets = $1.75 a sheet. Am I missing something?

From the original questioner:
Interesting responses. Contributor G, I tried slowing down the spindle speed feed rate to what you suggested for the 60-163MW I am using, and I fried the bit in about three sheets. Is diamond tooling really in the thousands of dollars? I'm not sure I could justify such an expense.

From contributor G:
A ball park for the PCD would be about $200+ (in stock). Without having the tool here, it seems to me the angles (primary and secondary) may be off.