Very large surface undercut with 12in dia. saw

[jlw™]

All,

 

This one is killing me.  I'm having troube with an undercut op.  I am trying to use Surface Finish Contour with no luck.  If I change to a 12in bull mill it will run just fine.  If I go to a "slotting saw" I get funny stuff with my tool and then an "STL Mesh" error.  Pics below.

 

If I have thickness set to 0.3in it shows both top and bottom radius:

 

 

If I change thickness to the actual 0.5in it shows the top corner as noncutting:

 

 

No matter what I do with that diameter and slot mill I get this:

 

 

and this when you click ok:

 

 

 

Any help would be greatly appreciated!

 

Can not share file on this one.

 

[gcode]

Do you have Gouge Checking disabled in the Gap settings?

This is necessary to process an undercut

[Guest]

You don't have to share the whole file...just break out the surface and several of the adjoining surfaces, and share that

[jlw™]

I changed this but it had not effect.  I did get it to run this path with the 0.3in thickness and that path did not have gouge disabled.  In the path with the 0.3in thickness I got it to run at 0.1in stepdown but I need a 0.01in stepdown.  When I change the path to 0.01in stepdown or the tool to any thickness greater than 0.3in it gives me the "STL" error.

[gcode]

are you trying to use a stock model to trim to stock

I'm pretty sure stock model does not support undercuts yet

[jlw™]

no, just straight up surface fin/contour.

 

 

[gcode]

that polygon mesh error is weird..are you using an STL to drive your toolpath???

[jlw™]

nope, using surface created from solid.

 

Here is a sample file.  Trying to cut the orange surfaces.  If you will notice a 0.3in thick saw will work... 0.5in will not.

help.mcx-9

[jlw™]

i cheated and just called it a bull mill to do the chamfer at the top.  I need to put the radii in too tho!

[gcode]

I wouldn't even try a surfacing toolpaths on that

I'd do it old school with wireframe and contour toolpaths

[jlw™]

which path would you use?

 

 

 

 

 

 

 

 

 

 

edited to be less dooshy

[Müřlıń®]

changed a couple settings and the 1/2" tool worked.

[gcode]

which path would you use?

 

 

 

 

 

 

 

 

 

 

edited to be less dooshy

2D contour and draw some wireframe...

[CJep]

Do you have access to the multiaxis tpaths?

I used a morph between two curves with TAC set to 3 axis.

I also sent the tool profile geom to a level and was calling it from there.

help_CJep.zip

[jlw™]

Well, apparently I have found another bug.  I heard back from CCS who heard back from CNC today.  There is an issue with undercut tools related to thickness and stepdown.

 

Good news is this issue is corrected in 2017.  Bad news is that it is not going to be ported back to X9.

[jlw™]

Do you have access to the multiaxis tpaths?

I used a morph between two curves with TAC set to 3 axis.

I also sent the tool profile geom to a level and was calling it from there.

 

 

Nice, thank you!  This will likely be the route I take.