NX Post processor unit mismatch problem

[AlexCLE]

I'm using the generic 3 axis mill post in NX9 for a part. When I run post and leave the unit setting as "Post Defined", I get metric but I need inch in my program. Though when I open this post in Post Builder it has inch set for "post output unit" in the Machine Tool tab. If, in NX, I change the units from "post defined" to "inch" then it gives me a warning about potential issues and I'm getting an alarm on my machine when cutting arcs; I think it's because of rounding errors when the metric numbers are converted to inch. For example, where the post makes the I value 1.765 it should be 1.7655 and I get an alarm. How can I make the post really use inches for units?

 

[Jaydenn]

Did you make this processor, or are you using a supplied post?

The first thing I would do to troubleshoot this issue is make a fresh post using Postbuilder.
Make sure it's inches, and use the generic control.
Then process your file and see if it behaves the same way.

However, if your post is outputting 3 decimals(as you describe...), it's probably a metric post. I just tested this and if you create an inch post, it defaults to 4 decimals for XYZ. Metric posts default to 3 decimals.
The post isn't going to do any rounding unless it has to.

If you're still having trouble, you can eliminate the rounding errors by changing the word format to support 4 decimal output.

Good luck,
Jay

NX 6.0.5.3

 

[markrief]

In Post Builder, create a new post, and select "Units Only Subpost", and select mill3ax as the main post.
This creates a subpost with only unit-sensitive parameters, like formats, resolution, feeds, ...
Then you can use part units or mm and get correct formating and limits.

Mark Rief
NX CAM Customer Success
Siemens PLM Software