Z Level Profile

[bcl001]

Hi everybody, since we upgraded [whatever "up" means], to NX7.5.3 [MP01] we are facing problems with the Zlevel profile operation. When machining a part [hole with chamfer 5mm x 2-degrees] the part is scrapped. When creating the chamfer by revolving a sketch there is no issue? GTAC advised to use the area command to select the region to be machined whilest I was using the depth combined with trim boundaries. However also with the GTAC option I still found some errors. Only changing the way the chamfer was created seems to work. Anyone a good idea out there?

GTAC number IR 1848774. I attached the part, for our company it is critical, mainly looking at reliability!

Anyone same experiences or tips out there.
I attached the part.

Bert

 

[berri2]

Hi bcl001,

Try this new strategies.

I have done some, chamfer mill with zlevel profile in NX 7.5

I haven't got any problem with it. I have used helical milling too.

Thanks.

 

[bcl001]

Hi Berri, when I generate your program, I still have the damaged part. I attached a picture to show you where the problem is. It is small but within "world of dies" this is terrible, especially because we start this finish machining after hardening, so already a lot of time spent [and this is a very easy die, for the bigger dies with more complex shapes it will be nearly impossibleto do a visual check, and it shoul not be necessary to do]. But the most critical issue is reliability [that is what i am looking for in the NX software and not some kind of nice TC-app for any I-pad]!!!

Thanks for more tips and also hope Siemens-employees have some a closer look and response.

Thanks, Bert

 

[berri2]

Hi Bert,

You are right, is a toolpath bug...

I attach you another strategies, I hope this ones can work.

Thanks,

 

[bcl001]

Hi Berri, we need to machine the chamfer&hole in one single approach/departure operation, due it is a already hardened die. That is why we choose for Zlevel-profile with ramp-on-part strategy. However I can solve it by creating the chamfer not by chamfer feature but using the revolve-subtract of a sketch. You can see this in the initial part within the modelling-tree [make current part last feature and suppress chamfer]

But it can not be guarenteed that our engineers are not using chamfer feature during the design.
That is why i am looking for Zlevel-profile setting somewhere to avoid this toolpath-bug.
Bert

 

[berri2]

Hi Bert,

I think that you can machine the hole with helical milling and later a finish strategy, like z level corner etc. After this you can use, a planar mill operation for the chamfer mill.

Tell me some good news.

Thanks,

 

[AGAINSTME]

Hi bcl001 and berri,

I downloaded your part and with NX 7.5.3, when I first generated I faced the same error.

Just changing the inside and outside tolerances I worked perfectly, it sounds me weird that within "world of dies" you are using such a big tolerance..

Try and tell me, if you want I'll upload the workpiece

 

[bcl001]

Hi AGAINSTME, if you postproces the operations the output only creates more points during the transition to the next Z-level. The dies are used for aluminium extrusion, where the chamfer acts like a "break/choke". Any small, within 0.02 mm, deviations are acceptable, but the toolpath-bug is totally unacceptable.
Furthermore I will try your change of tolerances to see the result, thanks Bert.

 

[berri2]

Hi AGAINSTME,

NX 7.5.2.5 MP1, I have changed the tool int and tool out tolerances and the toolpath bug still in the same way...

Maybe is the NX update..., I prefer to contact GTAC to see another point of view.

 

[bcl001]

The only solution for this moment that seems to work without "special CAM setting" is not to use chamfer but revolved sketch. Also tried narrow tolerance, then suddenly it bugged the other hole ?!?!
I think I have to wait for GTAC answer.

Bert

 

[capnhook]

Good luck, bcl001.

I would be curious if you got an answer from them, and then what the answer would be.

This type of helical path works great on Brand MC and Brand C. I wonder what the holdup for NX is?

Congratulations on your "up"grade.


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