[bitviper]

Here's my setup:

Machine: Zenbot mini
Spindle: Wolfgang WW-650
Mill Bit: Ball end mill, 2-flute, 1/32", 1/8" shaft
Mach 3 Software
Inkscape + gcodetools for gcode creation
Material: black surface plastic on white core 1/16" thick


So, I'm able to make various legend plates for our machines. I do one pass for the writing where I edge the surface to make the white lettering. I then cut the plates out with the same ball end mill going 0.015" depth steps until I break through. I have a piece of sacrificial stiff cardboard underneath that is temporarily glued to the machine. In order to hold the black plastic in place, I glue it to the cardboard with 3m 90 adhesive spray.

The big problem is that when the end mill reaches the bottom of the plastic, it starts to pick up the adhesive material which sticks to the bit. I get a bigger and bigger glob of black plastic mess that messes up the look of the black plastic. I have to constantly scrape away the goop with a flat screwdriver. I would love to know how to hold the plastic down and still allow for my bit to cut through it - meaning I still have a sacrificial layer in place. Does anyone have any suggestions?

[bsm2003]

Tape along the edge where the cutter won't be cutting. You avoid the gluing all together. Or use some type of clamp you can screw to the bed. Something like this Toggle Clamp - 500 Lb. Horizontal Toggle Clamp