# How do i get a smooth result in the roughing cycle?

Mark:

Great project.

What type of wood are you using, and how did you determine the federate and plunge rate settings for that wood?

Very nice result, Oliver!

But I don’t understand why unchecking the angle limit would make the change. With a 50 degree limit on the parallel finishing and 40 degree limit on waterline, there is a 10 degree overlap between the two regions. For years on 3D parts I have regularly used 47 and 43 degrees as the limits, and that is still enough overlap while using each finishing technique where it is most efficient (parallel on flatter areas and waterline on steeper areas). There is no angle limit on the roughing–it always roughs the same. Unless there is something different about the “Carbide/Nomad” version of MeshCAM than the “free range” version…

Randy

Thanks! Yeah I am not sure why it works exactly, but im very happy THAT it works now Maybe Jorge or Robert can explain more details on this.
@3dsteve: Thanks, I used a Jatoba wood, but i actually like the (local) redwood burl that i used before better in some ways If you meant me anyways and not Mark.

Oliverblum:

Did you start with an STL of the car, or get a DXF and have meshcam ‘extrude’ it into 2.5D?

I am trying to decide if I am better off to design something in one of my CAD packages and export an STL that contains all the depth info, or just use a DXF for the shape and then use Meshcam functionality to get the depth info.

What feed rate did you use on the wood?

Once again, what a great looking project!

Hi!

I used a STL of the car, which i think is the preferred way. Using a bitmap works too but i think using a STL gives you more control over the output.

I used all the default settings of the Carbide auto path. Took a few hours to carve this.

Thanks again

what exactly IS surface angle?

A good question, dr_g. Surface angle is the local slope of the geometry relative to horizontal. A horizontal surface has an angle of 0, and a vertical surface has an angle of 90. As I said above, parallel finishing is more efficient on surfaces between 0 and 45 degrees, and waterline finishing is more efficient on surfaces between 45 and 90 degrees, for a given stepover/stepdown.

I allow a few degrees of overlap between the two regions just to make sure everything gets machined.

And for ultimate surface finish if time is no issue, use X+Y parallel and waterline with no angle restrictions over the whole workpiece, as I think Oliver did above.

Randy

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Hi,

thats correct, i used X+Y parallel and waterline with no angle restrictions. The X+Y Takes a lot of time and i wonder if just X or Y would be sufficient too.

Good explanation Randy!