Luban rounding raised letters on CNC

I am trying to CNC raised letters using the SM Flat End Mill Bit… My problem is that LUBAN is progressively stepping up and down at the sides of the letters so the tops are like mountains and not square as they should be. I am using an imported SVG from inkscape and I also notice that LUBAN represents a pointed bit in the preview, but this may be just a graphical limitation. I posted this of FB and the consensus is to try Fusion… Is LUBAN not capable of this SIMPLE CNC task??? I find it hard to believe I am the first to notice this so perhaps I have a setting wrong. Hopefully my photos will be more explanatory.!

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Are you absolutely sure that’s a vector image you are using? I know that when I use Inkscape to convert an image to SVG I have to delete the original jpg, bmp or whatever before saving otherwise the raster image is saved with it and is loaded into Luban.

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I created the fie in inkscape using text, then converted the objects to paths. Saved as svg and imported it into Luban… Now in Luban I had to process the added svg file as a “Relief” and when I tried processing it as a vector it would not keep the raised letters. maybe processing it as a raster is the problem? if so how can i do this? image

It looks like you might have saved the text in Inkscape without a Stroke width. In the panel on the right hand side, set the Stroke width to 0.1 or something non zero, see if that works.


Select process as Vector in Luban.

EDIT: Sorry, I was trying to do two jobs at once and I think I have misunderstood what you are trying to do. I’ve never tried a relief carving in Luban, I’ve always used Fusion360, a pocket would do the job here.
As it says when you enter the CNC part of Luban, its an alpha feature, I think there is a long way to go.

Ok, thank you for trying. I was trying to avoid learning Fusion for what I thought would be a rudimentary task, but it seems like Fusion is the way to go anyhow… I hope they keep it free for the hobbyists!

What is your density set to?
I’m not sure why SM/Luban uses that term. No one else does. It should be called ‘step-over’. Set it to the highest setting and it will reduce the distance between passes.
You’re always going to get some stair-stepping no matter what program you use with a flat end mill. You need to use a ball nose or v-bit.
Fusion will give you more control of your tool paths.
For making signs there are a couple of other options. Easel by Inventables works really well and has a great preview. Carbide Create is another one. F-engrave is great for v-carving but the interface is really lacking and you need to do some g-code editing.

I had the density set to 4 with a .05 step down… i just changed the settings in Luban to a density of 10 with a .25 step down an graphically they still look like peaks but I can give it a run later when I get home. I will also look at the other programs you suggested, although I am playing with Fusion right now. I am well versed with AutoCad so some of the concepts I am used to will likely help me in the learning curve! As far as the bits are concerned I had thought the flat bit would produce better squared tops, but I am a complete newbie at this and I bought the SM to learn… This is a hobby for me! Thank you for your suggestions!

Wait. Maybe I misunderstood. You’re trying to cut out the background and have the letters untouched? I was thinking you were trying to have them beveled and just didn’t like that they weren’t smooth.
In that case export as a png instead of an svg.


Yes, this is correct, I want to cut the background out, leaving the letters raised from the carved back surface. I just went and tried saving the file as a png and importing into Luban and the preview still is showing peaked letters but maybe it will print differently. I can give it a try tonight or in the morning and see if it works.

Share the file you’re using as your source.
We can make sure there isn’t something funky with it.
Which version of Luban are you using?


Ok, thank you so much for the time helping me… I am using Luban 3.13.1 - Hopefully this is downloadable, otherwise I can create a dropbox link. you should be able to right click and save the svg. pavlik CNC raised letters

I’m not sure what’s happening with it.
I’ve never tried to do an inverted svg before so not sure if it’s an Inkscape problem or Luban or both.
It was dropping out letters of the file you gave me. I converted “object to path” and then they showed up but still either refusing to create g-code or seeming to give the rounded edges.
If I export as a png and use that in luban and invert it does what you want it to do though.

Thanks, I even tried creating it in Luban but there does not seem to be a way to do it using the text tool in luban either. I originally thought it was some kind of setting.