Uniform drill pattern on 3d finish - How do I get rid of it?

[Kaminel (Kami nelson)]

I am new to CNC, I have the nomad 3 and used carbide create when I add the 3d finish I keep getting this pattern across the piece. I had hoped it was a simulation error but it is actually drilling almost all the way down to the bottom in this uniform weird pattern. I can’t seem to get it togo away. Can someone help. I will gladly provide more details, but being new I’m not sure what all you need to help me diagnose the problem. I create another 3d piece prior to this one and had no issue with the same settings.

I’m using the same png for the rough, which doesn’t have this pattern and looks awesome already but for some reason the finish always has this. I used this tutorial to create the PNG: Cutting STL models with Carbide Create Pro (nearly-2021 edition)

Thanks in advance.

[fenrus (Arjan van de Ven)]

what kind of endmill are you using for the finishing pass (and which F&S) ?

also just to make sure, the PNG generated by the tool did not show these lines ?

[Kaminel (Kami nelson)]

Here is the PNG, which I do not see the pattern on.

I am using the following endmill and settings.

Thank you so much for trying to help!

[fenrus (Arjan van de Ven)]

I’m inclined to think it’s either a mistake in the stepover of the toolpath, or a artifact of the simulation…

if you change the angle of the finishing pass, do the lines change with the angle ?

[Kaminel (Kami nelson)]

@fenrus
changed the angle and still got the same pattern. Looks identical to me.

[Kaminel (Kami nelson)]

@fenrus
changed the overstep to 0.001 and got this.

[fenrus (Arjan van de Ven)]

with the angle changed but the lines not changing…, I suspect this is a simulation artifact somehow.

[Kaminel (Kami nelson)]

@fenrus
How do I get rid of it?

[fenrus (Arjan van de Ven)]

if it’s just a simulation artifact it won’t be in the actual cut.

this is technically more complicated but there’s a tool called “camotics” which is open source and is another way to simulate toolpaths… worth checking that perhaps.

Looking at the time it’s estimated to take I still wonder about the toolpath though… that’s a long long time.

[Kaminel (Kami nelson)]

thats the issue it is in the cut. I thought that too but started the finish and it started putting the holes in the wood.

[fenrus (Arjan van de Ven)]

that sounds like a bug… time to email carbide 3d support…

[Kaminel (Kami nelson)]

Thank you so much for all your help!