CAM in NX - how to slot and what is "steep"

[Iguana999]

I have two novice questions about CAM in UGS NX. The first is that when I attempt to generate a tool path, I often get the error message "the part cannot be cut at any levels" when the mill tool isn't significantly smaller than what it is trying to remove. For example, I might be attempting to cut a 3/16" slot with a 3/16" mill tool, or engraving lettering that are a minimum of 0.005" wide with a 0.002" diameter tool and get that message instead of a tool path. This is common when cavity milling, but the equivalent in contour milling is that it will ignore the area (so only part of my letters are machined). Does anyone know how much smaller the tool needs to be than what it's trying to machine, or better yet, how to prevent getting this error other than using a tiny mill tool?

My second question is: what is meant by "steep", "non-steep", and I think I saw "direct-steep"?

Thanks,
John

 

[markrief]

Check your clearance values and minimums in Non Cutting Moves. For example - the tool may fit, but if the minimum helical engage is set to 200 %Tool, there is not enough room to engage. Also if if the holder is too close (less than the holder clearance value), it won't go there either.

Steep and Non-steep are used to separate regions that you want to apply different techniques to. For example, you may want to use area milling with a follow pattern in non-steep areas (nearer to flat), and zlevel cutting on steep areas (nearer to vertical). The steep angle controls where these are divided.

Mark Rief
Product Manager
Siemens PLM

 

[Iguana999]

Thanks Mr. Rief for the explanation of what steep is used for! Unfortunately, I'm still having trouble with the tool not engaging. I made a simple block to test it on that had 0.01" deep slots in it. The first slot was 0.0625" wide and each slot thereafter was widened by an additional 0.0005" until the last slot, which was 0.067" wide. Even with setting the starting/retracting moves to plunge and checking that there were no clearance issues and that the side/floor stock was set to zero, I found that NX would cut some of the slots with a 1/16 mill tool but not others. Interestingly, it wasn’t generating tool paths for the widest slots while ignoring narrower ones, but would skip a few and then go again randomly. Reducing my intol and outtol increased the number of slots that would be attempted such that at 0.00001” all but the 0.0625” slot was cut. Also, I found that selecting the walls for cutting in addition to the floor allowed more slots to be cut. The drawback of widening the slot is that multiple passes are then required, with the first one doing almost all the work and then the second just creating wear on the tool and wasting time. I could edit the tape file to remove the second pass, but I think that I am missing something obvious. Any more ideas what could cause it? Thanks for your help!
John

 

[markrief]

There are many ways and operation types that can be used to cut the slots. I would contact GTAC or your reseller with a test part, and let them take a look at it.

Mark Rief
Product Manager
Siemens PLM