making finishing paths more efficient?

Here's the place for discussion related to CAM/CNC and the development of the Path module.
falviani
Posts: 122
Joined: Tue May 07, 2019 8:49 pm

making finishing paths more efficient?

Postby falviani » Fri Nov 01, 2019 8:05 pm

Hi all,

I have a few projects in mind where I'd like to have a roughing pass with a largish cutter (up to 1/4") and then finish with a small cutter (around 1mm). As an experiment I put together a quick test where there was a large pocket in the model and then a couple of small blocks extruded from the pocket bottom 1.1 mm apart. When I did a roughing pass with a 3mm endmill then a finishing pass with a 1mm endmill (to cut between the blocks) the finishing pass processed the entire area already cut with the 3mm endmill. In other words, a tremendous waste of time. Is there a way I could have restricted the finishing pass?

I believe in Fusion 360 (which I use occasionally) a path can have a 'rest' attribute, which causes it to ignore areas that have already been processed. I'm looking for something equivalent, even if I have to do some manual masking.

Thanks in advance,
Frank
chrisb
Posts: 28036
Joined: Tue Mar 17, 2015 9:14 am

Re: making finishing paths more efficient?

Postby chrisb » Fri Nov 01, 2019 11:08 pm

You can reduce the StartDepth. I usually edit the expression and subtract the amount I want to skip.
falviani
Posts: 122
Joined: Tue May 07, 2019 8:49 pm

Re: making finishing paths more efficient?

Postby falviani » Mon Nov 04, 2019 8:45 pm

It's not so much the depth as avoiding entire areas. Consider milling a sign - the roughing cutter won't be able to cut between letters (and only roughly around those letters), and I want a finish pass to ONLY cut between letters and refine their shapes.
chrisb
Posts: 28036
Joined: Tue Mar 17, 2015 9:14 am

Re: making finishing paths more efficient?

Postby chrisb » Mon Nov 04, 2019 8:57 pm

Ah, that's something different. Have a look at https://forum.freecadweb.org/viewtopic.php?f=15&t=40399.
herbk
Posts: 1913
Joined: Mon Nov 03, 2014 3:45 pm
Location: Windsbach, Bavarya (Germany)

Re: making finishing paths more efficient?

Postby herbk » Mon Nov 04, 2019 9:13 pm

falviani wrote:
Mon Nov 04, 2019 8:45 pm
It's not so much the depth as avoiding entire areas. Consider milling a sign - the roughing cutter won't be able to cut between letters (and only roughly around those letters), and I want a finish pass to ONLY cut between letters and refine their shapes.
If i need this, i use a little workaround:
If i work with an 3mm endmill, i use a toolcontroller for a 3,2mm endmill for the first work, what lefts 0,1mm material.
For the finish path i use the 3mm toolcontroller and a contour OP to remove the rest.
Gruß Herbert