What am I doing wrong?

[bpimm]

Total novice here, I am not a machinist and have never used anything CNC until now.

The part I'm trying to make is a bracket for a heim joint. The top of the part is rounded and when I run waterline finishing it leaves several ridges on the rounded surface. I tried X Y finishing and it did the rounded top good but it didn't finish the flats. I even ran waterline at a stepdown of .001 and it still left some ridges not as many as the pic but some were still there.

Here is a pic of the ridges it left.



and what cutview shows at .001 stepdown.



I'm sure I'm just not setting things up right.

Brian

[robgrz]

Brian-

It looks like you might be using the min/max angle settings for the parallel and waterline finishing. Can you tell me what settings you're using on those?

Generally you'd want those to overlap where the parallel max angle might be 60 degrees and the waterline angle might be 40 degrees. That would cause the entire part the be fully machined.

-Robert

[bpimm]

Ok, I wasn't sure what the min surface angle did so I left it at the default 60*, so min surface angle means that it will ignore surfaces under 60*?

I ran it again using 60* parallel and 40* waterline and it looks good. With these settings will it use waterline from 40*-90* and parallel from 0*-60*? Am I understanding it correctly?

Thank you
Brian

[robgrz]

That's exactly what it does. This has been a very difficult thing to communicate - I've never really been able come up with a universal way to do it. Sorry for the confusion.

-Robert

[bpimm]

Thanks, Makes sense now. I have tried a couple different programs so far and yours is the most intuitive so far, to me anyway.

Brian

[ViperTX]

I'm still confused how is the angle measured. A pictorial would certainly help.

Thanks,

Paul

[bpimm]

I'll try to explain my understanding a bit better, Robert please correct me if I'm wrong.

If you look at the table as the 0* plane and the Z axis as the 90* plane then if you use parallel finishing set to 60* then any surface that falls between 0* and 60 * from the table in any rotational orientation to the Z axis will be finished by the parallel finishing and any surfaces from 60* to 90* will be ignored. Then any surfaces from 40* to 90* from the table in any rotational orientation to the Z axis will be finished by the waterline finishing and any surface from 0* to 40* will be ignored. This allows each finisher to work in the area it works best. It really cleaned up the tool path on my part.

Hope that helps clear it up.

Brian

[ViperTX]

Thanks, it is starting to make sense.

Paul

[robgrz]

Here's my attempt: Surface Angle Limits - MeshCAM Blog

Let me know if this helps.

-Robert