Machining Phenolic

[ranchak]

I've looked around on the interent and can't seem to find an answer. I'm machining 3/8" thick phenolic, G10FR4. What I found is guys cutting with 1/2" - 1" diameter cutters, cutting at 800ipm. My problem is I am using a 13/64" cutter and I can't cut at 800ipm. I have a FlexiCam router with a 3HP spindle. I was cutting at 30ipm, a depth of cut at .125". Spindle speed around 10,000-12,000rpm. This was working until the cutter got dull, which was pretty quick. Well I scrapped the material I was working on and ordered another piece, but I really need to get this figured out before I waste another piece. Can anyone please help? Thanks in advance.

[ger21]

I'd reduce the depth of cut and increase the feedrate to 80-100, keeping the same rpm.
Edit: If that has glass fibers in it, ideally you'll want to use special cutters made for that stuff, as regular ones won't last long as all.

[txcncman]

G10 is a fiberglass composite.

[ranchak]

Thanks for the reply. What I could see most guys are using carbide cutters usually two flute. I was thinking of going to .063" depth of cut and increasing the speed some. I just checked with GFWizard and it says using a .25 end mill at 7000rpm the feed should be 75.8ipm. I guess maybe tomorrow I'll try cutting some plywood at these settings and see what happens. I'm worried that the speeds are going to be a bit fast for cutting a hole that is 2" in diameter. I'll never know until I try!

[txcncman]

Nothing wrong with slowing things way down. 3500 RPM and 20 IPM maybe. And increasing axle DOC to 0.200.

[ranchak]

I got better results running with the settings that I got with GWizard. The edges are not real smooth in some areas, I'll wait to see what the customer thinks.

[FlexiCAM]

FlexiCAM uses custom made three flute cutters for machining phenolic.

We are doing LOTS of them (most machine vacuum tables are made from phenolic, so you can imagine).

Tools are available in 3/8" and 1/2".

For your application I would recommend the 3/8x1/2x3/8x1-1/2 3FL Upcut (FlexiCAM P/N TP096).

Drop me a PM if you are interested.

[rockcliff]

phenolic board is for sure one of the top 5, on my nasty material list,

I normally will use a rasp type carbide cutter, it will leave a rougher edge, but seems to be better for cutter life.

I always try to order Cotton based phenolic, which is a bit easier to cut then the fiberglass based

[uli12us]

For this material yo should use diamond coated tools. They are rather expensive, but lasts much longer than any other tools. If you can get it, you should buy a tool with filleted edge, that increases the tool life dramatically.