CNC milling Cast Acrylic for LED Lamp

hello so I wanna use the cnc function of the SM2.0 for the first time and want to try engraving a logo on cast acrylic and here’s what the plan was.
first I wanted to engrave this Batman stencil in Relief mode with a 30° bit with a 0.2mm tip so far so good and the simulation looks good as well. I took the default settings for acrylic in Luban work- and plunge speed 300mm/min and a 0.4 step-down.

then I wanted to cut a frame with a flatend mill with the same settings but if I do the second tool path Luban changes both images in vector mode and then it looks like this

is it not possible with Luban to do two different settings and a bit change? I mean then why you can even create two toolpaths if you have to do it the same way as the first or did I anything wrong?
or do i HAVE to do it in two complete separate jobs?

The easiest way is just to do two jobs. It’s really not bad, especially because you have to do a tool change anyways. That’s what I do, and then I adjust the work zero Z for the new tool, and carry on.

Hm ok i think your right and its the easiest way to do it. What do you mean by work zero Z?

When you run the second job, you’ll have to set the work origin again. It’ll have it saved from the first job, but with a new tool the Z height might be a little different. Simply adjust the height for the new tool, and carry on. The X and Y shouldn’t change at all.

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Ah ok thanks for the tip! The z offset is like the others with the card or what distance should i set for it?

Yep, just use the card.

Ok nice :+1:t3: A befor i forgett is the workspeed ok or too slow and with how much rpm should the toolhead spin? :eyes: sorry for all the questions never used it befor :see_no_evil:

The speeds look fine. If you’ve got some spare stock acrylic, I would recommend testing the speed on that. I also run a test on spare stock, just to make sure my settings are good. As far as spindle speed is concerned, I don’t believe you can change that in Luban. I’ve always had to edit the gcode directly. You shouldn’t need to change it though.


Might be? Will be.

One of the reasons that production machines all use tool holders (such as CAT and BT series) is that once the cutting tool is tightened in its holder, it needs to be measured to determine exactly where the end of the tool is. The holders all have flanges that provide a common datum surface, allowing two coordinate systems to be joined. The first is the relationship between the machine as a hole and the plane on the spindle where the flange rests. The second is the relationship between the flange on the tool holder and the tip of the tool.

All this can be made far easier with a setting gage (also call preset gage and some other names).

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Ok thanks for the reply and the tipps you two :+1:t3:

I was able to get a decent result but in the flat areas are some stripes that remains. Can i get rid of it when i lower the setting for parallel toolpathes lower

Are you using the 30 degree bit to carve all that area?

Yes i dont know how i make it work with 2 different tools

If you’re carving area like that, especially because it’s flat, you should be using a flat end mill - not an engraving bit. If you were doing a vector outline, or detailed engraving, an engraving bit would be fine. But for what you’re doing, you need the flat end mill.

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Can it reach in the small egdes without rounding them?

When i do a simulation with the flatend mill that came with the snapmaker is it not looking that good the right ear is not completely engraved aswell as the eyes

Do you have a smaller end mill? If I remember right, you’re using a 1.5mm? If you have a 0.8 or 0.5mm that would give you you’re resolution.

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Or just reduce the stepover so that it’s appropriate for the bit being used. Probably going to be a stepover of like .2mm or something. Or can Luban generate another pass at a different angle?

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Maybe these bits @BluegrassBlaster ?

Fippy 10 Stück Schaftfräser Cnc Fräser, 1/8 Zoll Schaft Titanium Coated Fräserset Hartmetall Gravur Bits Carving Drill für Holz PCB Weichmetalle 0,8-3,175mm

@brent113 thats what i test next but i dont find an option where you can do 2 toolpaths with different tools or angles