Cutting Starboard

[Greybarn]

We cut 5 sheets of 1/2" thick Starboard yesterday, held down on the vacuum table, and everything went well. We used a 1/4" diamter O-flute, up cut bit, running at 18,000 RPM and 1 IPS. My question is if I use a 2 flute up cut bit, and increase the speed to 2 IPS, then can I expect the same clean cut? Or is that a trial and error thing?
Thanks for the help.
Regards
Peter

[bleeth]

I pefer straight cut O-flutes for plastics. I do 1/2" in two passes at 1.5ips and ramp in with single flute 1/4" O at 12,000RPM. I have found the parts don't move when the last bit is cut even for small parts like they do with up cuts.

[Greybarn]

I will give the straight O-flute a try at those speeds. I was trying to cut down on the total amount of time. We had one sheet that took almost 60 minutes to cut (because we had so many parts nested into it). Thanks for the tip.
Regards
Peter

[gundog]

I cut a lot of 1/2" Seaboard which is the made by a different manufacturer than Starboard. I use a single up cut .250" bit Onsrud 63 series bit and cut it in one pass @ 1.7" sec. I cut a lot of small parts so I leave a .050" skin and cut the parts out of the sheet with a laminate trimmer. If the parts are large enough you would not need to leave the skin. The bit and cut speeds are recommended by Seaboard they have a nice printed brochure with the info. I believe Starboard and Seaboard are the pretty much the same but made by different manufacturers.

When cutting plastics make sure and use an upcut bit or you risk the chips re-welding the chips need to be removed from the cut. You might get away with a downcut bit if you used air to blow the chips out but I am not sure what the advantage would be.

Mike