Stepper Motors for Drag Knife MPCNC

Hi all,

I’m planning on repurposing a Burly build into a drag knife machine. Has anybody tried making a drag knife machine using the smaller ~36oz-in stepper motors you’d see on your average FDM 3D printer? I have a ton left over to recycle for this machine. I’m guessing it’ll work, but I have never made a drag knife machine and don’t know what the demands are on the motion control. At the extreme end, I’d like to try cutting fiber gaskets with this machine. If any of you have experience you’d like to share, I’d love to hear it

Adding a drag knife to a 3d printer works no problem. I’d guess that the doubling up of the motors on the Burly build would more than compensate for it’s additional mass.

I suspect cutting any level of detail in your gasket is going to be a problem as you need a means of holding the material down without damaging it. If you’re doing this a lot a laser might be a better option Making Gaskets on a CNC | The Hobby-Machinist

I’m not there yet but gasket cutting is quite high on my “why I need a laser” list.


Got it, thanks. Maybe I’ll have this machine configured to do both drag knife and laser duty. My machine is made for just under 24x24" work area, so my plan was to clamp down the edges of a 24" wide roll, stretch it taut, and leave tabs when cutting that make it easy to punch out later but not lose workholding. I’ve been wary of those diode laser things being too wimpy and needing to go straight to a CO2 laser, but that thread you posted has me convinced. Thanks for taking the time to respond