Inventables Community Forum

End mill selection

Howdy. First time poster here.

I’m new to CNC in general, so, while trying to not get into overly extraneous detail, here’s what I’m wunnerin’…

I’m using an X-carve to cut Magnum Magnetics magnetic sheeting. If you’re unfamiliar with the stuff, it’s flexible PVC sheeting impregnated with ferrous metal particulates; typically used for vehicle signage. For obvious reasons, cutting shapes from it by hand is out of the question, and the stuff’s metal content ruins razor blades pretty quickly - requiring constant blade swaps when using a drag knife - no good. The drag knife also creates “furrowed” edges as the blade plows through the material… again, no good… especially around tight curves.

While certainly not the first to give it a go, I’ve devised a method using what I call “channel boards” with the X-carve to mill shapes from the sheeting. Results thus far have been very pleasing… nice, clean, burrless edges and no raised furrows as with a drag knife. I imagine most of you can already envision what I’m doing, so there’s no need for a lot of explanation and it isn’t really pertinent to my question anyway. However, if more details are desired, no problem… 'jis lemme know. (The mill plunges through the sheeting and rides between the walls of a pre-routed channel… yada, yada, yada)

I first used an end mill that Inventables sells - Solid Carbide 2 Flute Straight End Mill (.125") - Here’s a link…

… also purchased some .0945" Kyocera 3-flute straight mills via Ebay. They might make slightly cleaner cuts, but wear faster. Once worn, neither do such a great job. I’m cutting only .030" of sheet-thickness and the Z can be adjusted so that a “fresh” section of the end mill is cutting, thus getting more use from it. (Incidentally, I’m thinking on how to make the Z “oscillate” between a min and max height while riding through the channels, thus using all of the mill’s cutting length throughout a job).

The above being said…

My original thought - the whole reason for getting the machine - was that an end mill intended for metals should be able to chew through a mile of the magnetic sheeting before dulling… but have since come to realize, that while the assumption likely is true, said end mills might not produce the desired cutting results when applied to plastics. Thus far, I’ve experimented only with the straight-flute plastic/wood cutters mentioned above and a few down-cut spiral 2-fluters (straight flutes win, hands down).

The stuff is plastic, but I reckon the metal content makes it a bit abrasive or sumpthun… thus, as with razor blades, the hastened wear on the end mills.

Sooo…

I’m looking for an end mill that does at least as good a job as those thus tested, but that last longer. I’m willing to pay for premium if need be, just don’t want to waste what little money I have left.

Will something intended to mill metals work on plastics in the first place? Is a “coated” end mill what I’m after?

Any recommendations?

Regards,
Kevin

Hi Kevin,
I’ve tried similar with my Roland sp300 realizing that’s not the way to go. Are you cutting with the X-Carve or scoring? Scoring always seems to work better for me.