Slicer Settings for My Custom CNC Machine

What’s up y’all!  I’ve been on vacation for the holidays and I’ve been able to play with my new custom CNC.  I’ve been learning a ton.  I thought I’d have a blog post to share.

Extruder Width:

As you know, I’m using a 3d printer slicer and a custom VBA script to create the GCODE for my CNC machine.  I felt really dumb with one of the first things that I realized, but that’s how I learn best. Haha. In S3D there is a setting for “extruder” dimension, but then it also has a manual setting that overrides this setting. I had set the extruder to 2mm, but the manual entry portion still had 0.1mm from the process I had been using prior for my laser engraver. No wonder the CNC engravings were taking so dang long… It was making so many passes where one or two could’ve done a sufficient job. Whoops… A benefit of this though was that I learned that making multiple passes where one will do will greatly smooth the bottom surface. I still find it cleanest to use half the width so that the bottom of the engraving is well cleaned out and doesn’t overburden the motors.

Extruder Settings Screenshot

Depth and Speed:

I’ve been experimenting with different woods.  Pine really is a soft wood and oak really is a hard wood and should be treated accordingly.  With pine I can do 0.5mm per layer pretty easily and on top of that I can do two layers before doing the “infill” which hogs out the inside of whatever I’m engraving.  I was doing all of this at 600 mm/min, but I felt more comfortable at 500 mm/min. With oak, unless it’s a brand new bit I can’t use the same settings comfortably. I feel a lot safer with 0.3mm per layer and only a single layer before doing the infill. I’ve said it before and I’ll say it again I love being a turtle (anybody get that reference…) but in all seriousness, Simplify3D is awesome. The settings that can be manipulated are practically endless.



So far I haven’t seen as definitive a decision as others have shown and posted about. My fluted bit seems to be working just as well as a straight bit, but I’ve been using mostly regular wood not plywood. I’m using just regular ol’ carbide bits. In general they’re working great, but they really only seem to be working well for about 10 hours or so before it’s getting a little too weak for the relatively underpowered stepper motors and spindle motor I’m using for the conversion. One  of these days I might want to upgrade to geared stepper motors for stronger movement while dragging the bit through wood. Here’s what happened after 10ish hours of use:

I didn’t understand what was happening yet and did two basically back to back that resulted in the same issue.

That’s all for now, I’ll do a similar post after I gather more insight.

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