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Wrong Inch sizes for Metric Threads

Phenom
Phenom

When I insert Metric Thread, the Major Diameter is creating a wrong value and wrong pitch,  tothe nearest inch value (rounding up?). For M12 Hole Callout, everybody else at in the company gets correct value 12mm=0.4724….in where I’m getting 0.4375in. My M16’s Major Dia comes as 0.625in where as it should be 0.6299…in. I guess it's rounding up to the nearest 1/8".

 

When I find an click “Choose from Table” then the values change to the correct inch size. (Others don’t have to do this.)

 

Has anybody seen this before and know how to correct it? 

 

 

 

Michael Fernando


Die Designer
NX 11.0.2.7 + PDW

15 REPLIES

Re: Wrong Inch sizes for Metric Threads

Siemens Phenom Siemens Phenom
Siemens Phenom

Hi Mike,

I found out two cases

(1) i created a a part in metric units. Created a hole of 10.2 mm for a M12 X1.75 thread.

Then using ANALYSIS/UNITS i changed the units to inch. When i make a metric thread M12X1.75 (trhe major diameter value i get is 0.4724 inch. (attached is an image (image_metric.jpg))

(2) I created a part using Inch units. Using ANALYSIS/UNITS i again changed the units to mm.

Created a hole of 10.2mm. And now created a metric thread M12X1.75. Now the major diameter is what you are getting (0.4375 inch) (attached image image_inch.jpg)).

Best Regards

Kapil

Re: Wrong Inch sizes for Metric Threads

Phenom
Phenom

Thanks Kapil,

This issue seems to be a much more serious bug than I thought. According to your findings it shows that the culprit is NX’s Analysis/units and I’d been using it to measure Inch models in Metric (As NX offered). So this command seems to be jeopardising NX's "Thread" command.  

 

I contacted GTAC and we'll see what they could find.

Michael Fernando


Die Designer
NX 11.0.2.7 + PDW

Re: Wrong Inch sizes for Metric Threads

Gears Honored Contributor Gears Honored Contributor
Gears Honored Contributor

I agree that GTAC should look at this, but in the meantime why not use the "threaded hole" option of the hole command rather than adding the thread in a separate step? It seems to work correctly when adding a metric hole to an inch part.

Re: Wrong Inch sizes for Metric Threads

Phenom
Phenom

I'm in the process of cleaning up and issuing detailed drawings of an outsourced design. So I'm adding threds to drilled holes.

Michael Fernando


Die Designer
NX 11.0.2.7 + PDW

Re: Wrong Inch sizes for Metric Threads

Phenom
Phenom

Kapilsharma,

 

GTAC indicates that they are still unable to reproduce the issue as we both describe but they appeared to be working on it.

 

After your #2 step did you find a way to change back to get the correct values? My system seems to be permanently corrupted giving wrong Diameter and Pitch.

 

Michael Fernando


Die Designer
NX 11.0.2.7 + PDW

Re: Wrong Inch sizes for Metric Threads

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

Does it happen if you create a new metric part?

- open a new NX session

- create block & hole

- add thread

 

If it still happens, *possibly*...

your dialog memory .dlx or user.mtx file got corrupted.

 

Try this:

- look in the syslog (help -> NX log file) to find out where those files are at

---- By default they are in C:\Users\(your username)\AppData\Local\Siemens\NX100

---- or C:\Users\(your username)\AppData\Local\Unigraphics Solutions\NX85

---- or similar for your version

- close all NX sessions

- MOVE those files somewhere else

- start a new NX session

- go thru steps to re-create the problem

 

If this doesn't fix the problem, exit NX & then move thos files back

If this does fix the problem, it may just be one or the other file, you could try moving them back one at a time.

 

If it turns out to be "part specific", possibly try a File -> Utilities -> Part cleanup?

Ken Akerboom Sr CAx Systems Engr, Moog, Inc.
Production: NX10.0.3.5 MP16/TC11.2
I'd rather be e-steamed than e-diseaseled


Re: Wrong Inch sizes for Metric Threads

Siemens Phenom Siemens Phenom
Siemens Phenom

Hi Mike,

Sorry i cannot get it to work anyhow. I still get the same results as mentioned in my earlier reply and not even able to set off the discrepancy by changing the units again.

To me it looks like that creating a metric thread in an INCH part might be creating an issue (but you  mentioned your peers are already getting the desired result so not sure).

The way unit conversion for deciding a metric thread on an INCH part is decided might be toattly different than if you apply metric threads on a metric part (irrespective of using ANALYZE/UNITS).

But these are my assumptions only.

Do let me know if you get a positive reply from GTAC.

Best Regards

Kapil

Re: Wrong Inch sizes for Metric Threads

Phenom
Phenom

So are you saying that now your system is corrupted too? Did you try what Ken suggested? I will try when I get a chance.

 

Probably my colleagues haven’t used Analysis/Units and therefore their systems are not corrupted.

 

I spent a lot of time contacting GTAC. Sure I will let you all know, If we can resolve the issue.

 

Michael Fernando


Die Designer
NX 11.0.2.7 + PDW

Re: Wrong Inch sizes for Metric Threads

Gears Honored Contributor Gears Honored Contributor
Gears Honored Contributor

@mike_fdo What is the actual diameter of the hole that you are applying the thread to?