Hi there, I’m fairly new to cnc-ing in general.
I’m trying to engrave a pattern that I designed in photoshop. Carbide create managed to trace it well enough and turn that into reasonable approximate vectors. However the problem that I’m having is that when I create a VCarve toolpath, it generates a bunch of extra tiny paths. I’m looking for a single line through the middle of the curve however it creates a bunch of lines from that to the edge.
The reason why I find this to be an issue is because it’s an intricate pattern across a somewhat large surface (roughyl a4 30cmx21cm) and all these little cuts mean that it’s spending more time rising and lowering the cutting tool than it is actually cutting. (Carbide Create says 90 minutes, Candle says 2 hours 30).
Here’s a screenshot, with the issue highlighted. The grid is set to 6mm to help give a sense of scale.
I’m not sure the best way to go about avoiding this:
Could I get the vcarve to not add those lines somehow?
Is there a way I can get the trace to only generate a line through the middle, rather than a loop? Which would mean I could do it as a contour instead?
Perhaps there’s a way I could post-process the gcode to remove these miniscule cuts?
Maybe simply lying to the software and telling it that the bit is actually much wider could trick it into doing this?
Do you really need it that width? Do you really need the corners like that?
Can you cut the vector so that each side of the path is separate and then offset one half the distance between to get a middle line and use the profile path on the new center line?
You could create a spline/polyline that represents the centerline of the path, then assign a contour path with a vBit. Using a bit angle and depth that spans to the edges.
It’s been requested… either to turn off that feature altogether, or apply a max angle on any corners so it only gets the sharp corners you want.
Inkscape has a feature / extension called Centerline Trace
Processing these moves out would be problematic.
Changing the bit diameter should have no effect. The effective diameter is determined buy the angle. A larger angle, I think would create more pick moves. A smaller angle may reduce them, but would then cut deeper.
One thing that’s worth mentioning is that my workflow here was to use a pattern fill in Photoshop to fill the individual sections with my tileable patterns.
I have 16 of these I need to make, so ideally I wouldn’t have to manually adjust every line.
Perhaps using inkscape to trace the middle lines might be my next approach. Though every time I’ve tried inkscape I’ve bounced off it.
If you do use a No offset contour for a drawn centerline, you will lose the width/depth variation and any sharp corners (the same, consistent radius will be used everywhere)
If you just let the machine go, it will pick at things a bit, and the patience of allowing the machine to do that will net you a cut which varies in depth/width and which has sharp corners. Patience is a virtue.
In this case, as with the case of engraving constant width text, variable depth & corner picking are not needed. Patience is a virtue when you’re cooking ribs, or deer hunting… not so much when your expensive machine is wasting a lot of time.
Can you share the original image. I just tried it with an image I had & it worked pretty good.
That was mostly a comment on finding the interface of inkscape unintuitive in the past.
However that said, with your pointers from your first comment I’ve managed to achieve basically exactly what I wanted. Thanks for the recommendation, I’ve marked that response as the “solution”
