Recently i received an assignment from my supervisor:
Raw Material : Length 223mm x Width 81mm x Height 50mm (HDPE material)
Product size : I have attached the pdf drawing file
Anybody could show me which toolpath should i choose and what tools ? Besides that, i encountered problem that my material is warping, what should i do to preventing this happened ?
I'd first rough it out with a large diameter tool. We use 3/4 solid carbide a lot for roughing. Any size flat end mill will work but it has to be sharp! Warping is usually caused by heat from using dull end mills. So whatever you have that's sharp use it. For a 3/4 flat end mill I would run it roughly 2000 sfm with a .008-.01 chip load. Depth of cut around .1 and stepover of around 50%. And I'd leave around .03 of stock for my finish toolpath. For the finish I like to use 1/2 ball. Very sharp one for plastics. Raster is a good toolpath to use here. And I'd run that around 1300 sfm with a chip load of .005-.007. These speeds and feeds are determined by my machines limitations of having only 10,000 rpm spindle. For the raster finish toolpath, I'd probably change the machining angle to 45 degrees to see if that helped eliminate the warping. I'd run it with a step over of around .01 thousandths of an inch.
Hope this gives you some ideas