Originally Posted by
jwatte
I'm trying to make a plug for vacuum forming a part, and was thinking I could build it in a 3D modeling program, export to STL, vectorize in Cut3D, and then route in some thick MDF to create the plug.
It all worked very well, except when trying to route the MDF, it keeps slicing apart / de-laminating along horizontal planes.
My details are about 6 mm in size with about 10 mm stick-up above a more supporting surface.
I'm using a 0.5" HSS roughing end mill for the roughing pass, with 0.3" cut depth, 6,000 rpm, and 100 ipm feed rate.
I'm using a 0.25" carbide ball point end mill for the finishing pass, with 0.06" cut depth, 10% stepover, 12,000 rpm and 80 ipm feed rate.
Plunge rates are 1/2 of feed rates, but plunging doesn't seem to do any damage, only feeding into the thinner sections of the plug.
The roughing mill and the ball point both do damage to thinner parts, but the roughing mill is worse (for probably obvious reasons.) I'm coming at this from CNC milling aluminum, which is a somewhat more solid material than MDF, so any hints I can get would be appreciated!
This problem is not uncommon. Once the top layer is milled off of the MDF it will have a tendency to 'flake' off, especially around small details. You may be able to avoid this by using a straight flute or down cut end mill.
The other option would be to use foam for the plug.
James
James Harvey
Harvey Development Corp.
www.Harvey-Development.com
36" x 52" CNC Router
ULS-25E 12" x 24" Laser Engraver