how do I rough an undercut surface?

[monkeyman]

After more time than I care to admit, I was able to work out how to surface finish an undercut. However the surface needs to be roughed before I'm able to run the finish pass. Now I'm stuck again. Ideally I'd like to be able to run an undercutting "rough parallel" type of move to bring it in. But despite playing with all the buttons I can't quite get it to work. Is there something I'm not seeing here or should I start working on drawing lines to use for a traditional contour move?

 

 

 

[Matthew Hajicek - Singularity]

Could do copies of the surface finish, with wider stepover and increasing stock to leave.  Then trim the toolpaths to a boundary to save on air cutting.

[crazy^millman]

5 hours ago, monkeyman said:

After more time than I care to admit, I was able to work out how to surface finish an undercut. However the surface needs to be roughed before I'm able to run the finish pass. Now I'm stuck again. Ideally I'd like to be able to run an undercutting "rough parallel" type of move to bring it in. But despite playing with all the buttons I can't quite get it to work. Is there something I'm not seeing here or should I start working on drawing lines to use for a traditional contour move?

Depends of what modules of Mastercam you have. What do you have? What version?

[billb]

Classic surface rough/pocket supports undercutting.  I was just able to use zigzag pocket method (with finish pass off) to get cutting motion a little bit like rough/parallel.  I used the gap settings to order the cuts from the bottom to the top.  I used an entry point.  (Alternative - turn off roughing passes, turn on finish passes with nonzero spacing and more than one pass.)   Rough/parallel does not support undercutting.

[monkeyman]

@crazy^millman I'm using 2018 with what looks like most milling option available, is there a particular toolpath I should be looking for? I did forget to mention that I am using a 3x mill for this job.

 

@billb Would that would with only a single surface? The undercut I'm looking to do looks more like an upside down "T" so it's not a full pocket.

[crazy^millman]

18 minutes ago, monkeyman said:

@crazy^millman I'm using 2018 with what looks like most milling option available, is there a particular toolpath I should be looking for? I did forget to mention that I am using a 3x mill for this job.

 

@billb Would that would with only a single surface? The undercut I'm looking to do looks more like an upside down "T" so it's not a full pocket.

5 Axis Morph Between 2 Curves or Parallel to Curve with a Stock model in 3 Axis for the Tool Axis Control. 

In 2019 and newer Surface Finish Contour with Bottom to Top as the cutting motion. 

[Colin Gilchrist]

1 hour ago, monkeyman said:

@crazy^millman I'm using 2018 with what looks like most milling option available, is there a particular toolpath I should be looking for? I did forget to mention that I am using a 3x mill for this job.

 

@billb Would that would with only a single surface? The undercut I'm looking to do looks more like an upside down "T" so it's not a full pocket.

Surface Rough Pocket accepts an unlimited number of drive surfaces or solid faces. (sure there is a limit, but you can do 1000's of surfaces or faces)

[monkeyman]

@crazy^millman I have been playing with the other tool paths with no luck. Would you be able walk me threw a bit how to set up the multiaxis tool path for 3 axis?

[#Rekd™]

If you attach a file you will get many people helping you .