Lines in Relief carving

1

HI everyone. Anyone else ever get small lines while using ball nose bits on finish during relief carves? I get them all the time. If so how do you get rid of them? Sanding shows up as sanding marks if you can even get to the areas that need sanding.

I’m not leaning on the table and have a very good power filtering system so I’m not thinking that I’m getting electrical spikes. They happen on every relief carve I try. I was using 45° angle for finish pass then I tried 20° and both leave the lines.

I have a foreman with a qcw frame sitting on a Kreg bench that is braced up a bit.

I’ve checked that everything is tight with z axis. I do have an extra z stepper motor that I could try but before I do that I want see if anyone else has this issue. Lines are small and sit proud of the surface. It’s almost like the z axis comes up short for a pass then it comes back to normal again for many more passes before it happens again.

Thank you for any helpful hints in advance.

2

Hello Jeff and welcome,

I tend to think it’s easier to check the NC code first rather than the machine.
What CAM software are you using? If there is a way to tighten up the tolerance I would try that first.
Since it is a 3D surface the software will have a tolerance that it allows the cutter to deviate away from the surface. So the cutter is allowed go above and below the surface by that amount. If set too big that can give you lines noticable above and below the norm.

You can take your code into ncviewer.com and zoom right in on one of the lines and measure it. See if it is sitting up too high to the lines beside it.

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That’s great advice. I’ll try it. Thank you! I’m using Carveco with a tolerance of .001. I’ll use the viewer and see it there is anything going on with code. I’m trying it again today changing the step over on my .062 ball nose from 10% to 8%. I’ll also change the tolerance to .0005.

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you might try lowering your stepover in the bit settings. I had the same issue and dropped it a few points and it was all better.

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5

Cutting a new one now and did just that. Thank you!

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Let me know if that works better or if I was just blowing one out my ear!! LOL

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Update: I tried several of the things mentioned and got a perfect carve. I think the 8% step over might have helped but also I changed the tolerance of the finish cut to .0005. I also braced up my table better and didn’t use any other power tools and stayed away from the table too.
Thank you for all the help everyone.

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