undercut issues??bad model??

[Jadamson]

We are trying to bring all mold work back in house.We are now using nx5..I have taken a few intro classes and made alot of parts with this program but now im hitting a wall.I have a mold with a undercut but only have a 3 axis machine.So i have a "lolipop" style tool.the program will not follow the path of the modle in the undercut, it just passes it by finding the next vertical surface and connecting the paths together.so after some reading i seen i may needed to turn off the "prevent undercut" in the more menue on the cavitymill cycle.ok so to have the option to toggle it it makes me turn off "tolerant machining" after doing all this and setting my clearance for holders and such up i hit generate....I get error converting solid..hit ok a few times ..then says error converting solid-must use tolerant machining.So i cant gen with tolerant off but i cant toggle off undercut with it on.any ideas guys? the model is coming from solidworks.

 

[markrief]

As you have seen, in cavity milling you have to turn tolerant off to undercut.
You can also undercut with face milling and surface contouring.
You can get more detailed help if you call GTAC or ask in the nx.cam forum, available as part of your support.
Also, you are 3 releases behind - I recommend you move up to 7.5.

Mark Rief
Product Manager
Siemens PLM

 

[Jadamson]

thanks for the suggestion to upgrade but we have to work with what we have.

 

[Jaydenn]

Your best bet will be to avoid cavity mill for the undercuts.
Cavity mill has it's place and it's place is definitely NOT undercutting.

Explore the "fixed contour" toolpath options.

J

 

[wmalan]

Hijack on:

Mark, Upgrading is always suggested to our managers. Problem is many times it falls on deaf ears (for a variety of reasons based on reality or fantasy). Maybe pass along to the powers that be REALLY get the word out to Siemens customers about the benefits. I've been on 6 for a long time but my new employer just upgraded from 3! I"ll keep trying at my end.

--
Bill