Ramp Tabs

[Z3]

X4 MU2

In programming ramp tabs, I've had an issue with a tool movement causing an extra deep cut (-.5) inches. This has happened only on occasion and only on one or two parts out of a sheet of parts. The parts were not nested (placed manually) into a sheet. All the tabs were created from the same contour toolpath with the same tab parameters..?

 

Happens only on a few tabs. In checking the verify and backplot, it doesn't show up. It doesn't show up in the Techno control software preview used. Doesn't show in the nc file (at least I cant find it). When we run the program above the stock it creates an odd arc move in the -Z direction, comes up and continues the program. It takes place just as it is ramping down at the back side of the tab.

-Anyone had this issue or have a guess? Straight plunge tabs are fine.

[timhochs]

I do a fair amount of tabbing and have never had that happen. It sounds like a serious problem. If I had to guess though, I would look for the following.

 

Is the problem occuring in an arc move (G2 G3) or linear (G1 G0)? If arc, the plane (G17, G18, G19) might be wrong. Or the direction of the arc. You can force Mastercam to output linear moves instead of arcs.

 

Otherwise if the top of your spoilboard is at Z0 be sure to scan you code for Z-. This can be accomplished with a text editor such as notepad

using menu: edit: find.

 

Just guesses though. Hope you find the culprit.

[MotorCityMachine]

X4 MU2

In programming ramp tabs, I've had an issue with a tool movement causing an extra deep cut (-.5) inches. This has happened only on occasion and only on one or two parts out of a sheet of parts. The parts were not nested (placed manually) into a sheet. All the tabs were created from the same contour toolpath with the same tab parameters..?

 

Happens only on a few tabs. In checking the verify and backplot, it doesn't show up. It doesn't show up in the Techno control software preview used. Doesn't show in the nc file (at least I cant find it). When we run the program above the stock it creates an odd arc move in the -Z direction, comes up and continues the program. It takes place just as it is ramping down at the back side of the tab.

-Anyone had this issue or have a guess? Straight plunge tabs are fine.

 

dont quote me on this, but you might want to check in under settings, control definition manager,linear settngs, and make sure they are all set to "DO NOT BREAK LINEAR MOTION". Ive had this issue before and its always when im tabbing and running a new version of MasterCam that I have forgotten to change in the preferences right away. just my 2 cents, hope it helps.

[Patriot]

Are you using cutter comp?

[Patriot]

We have one machine that just does not like cutter comp. We haven't figured out why but when it is on a program going to that machine, the program may be correct, as well as the code, but the machine seems to have a mind of it's own and make random movements it is not supposed to.

[MBuck]

^ Our old Thermwood C53 Router really does not like ramped tabs, or tabs that are on arcs.

It usually stuffs the cutter deep into the table and dwells, or it goes about .250" into the table and then rapids to X0Y0.

The Software and control on those are ancient though.

 

That sounds exactly like what ours do MotorCity, it  occurs on the ramp down.