I designed a small hexagonal box and, cut it on my Nomad 883 (original edition). Despite the older machine, I am pretty new to CNC machining. I had some issues and, wondered if anyone has any insight or guesses about what went awry.
I designed this in Blender, exported to STL and, ran it through MeshCAM for the gCode. I used an older (c. 2016) version of Carbide Motion to run the job.
I used an extra-long (1” – 2.25" total length) .125” ball mill to be sure it had enough reach for ~1” depth. This run is in basswood.
The stock is 22.35mm (.88") thick. The parts are 22mm (~.866") thick. I carefully zeroed the machine using a feeler gauge. I know that is probably unreasonably close tolerance but, it seems to have cut everything ~1mm lower (i.e., removed 1mm from the top surface and cut 1mm into the wasteboard). Is that the expected behavior?
It looks like I didn’t save an mcf file for either of these, just the nc files. I can probably re-create them, though.
You have a fair point about 3D modeling vs. Carbide Create. I was originally thinking I would be working towards doing at least the lid with a flip jig (which probably still doesn’t necessitate 3D modeling it). I will see how far I can get with Carbide Create.
I had a go at re-doing it in Carbide Create. The time estimate on this seems a lot faster.
I am not sure I got my extra-long ball mill set up correctly. There didn’t seem to be anywhere to input length, flute length, etc. I’m not sure if that matters. I mostly just copied the Nomad 3 Hardwood #101 mill.
I didn’t see anything about finishing passes. Is there some standard for that?
Here are the files. I haven’t tried to run this yet. Any feedback is welcome!
The only geometric parameter that get’s used by the toolpath processor is diameter, angle, and the shape [end mill, ball, vee]. The only reason to save separate tools is to set the toolpath parameters separately for tool design & material.
There is no built in standard for roughing / finishing. You determine that yourself and program the toolpaths accordingly.
I’m curious why you’re using a ball mill. An endmill would machine all the surfaces flat & require less cleanup or sanding.
Otherwise the parameters look good. I might change the stepover on the first path to prevent the little plunges on the corners. And round off the corners on the middle vector on the lid so it fits the pocket on the body.
