Machining UHMW

[gundog]

Mike...
You say your straight parts have a good finish on the edge. Are they the same size as the round ones? I have noticed that these parts are vibrating as they are cut. Try boring the center holes and adding hold down. Then cut the outline.

Yes the same part such as one of my fillet/Rigging tables have straight sides with 2 corners having a 1" radius the flat sides are anywhere from 24" long to 40" long & 12" to 16" wide. The sides come out smooth and the corners always show more chatter. I hold down with vacuum and cut to a .050" skin and trim the parts out with a laminate trimmer because many of the other parts are much smaller. I usually cut these parts in one pass with a single flute spiral upcut .250" bit ran @ 1.7" per second 18000 RPM. These feeds and speeds as well as the cutter are what is recomended my the plastic manufacturer. Bit is a 63-700 series I am not home right now so I can't remember the last 2 numbers. Material is 1/2" Seaboard HDPE.

If you go to my web site and go to the products page you can see my tables click under the picture of the fillet table and also look at my custom products page for more stuff. The UHMW parts I machine are for my Anchor Locker bracket.

Mike