Thread size changes when thread type is selected

[Anonymous]

There appears to be a bug in the threading routine.  When 0.19(#10) inch is selected in the "size box" and 10-32 UNF is then selected in the "designation box", the size box changes to a #8.  I tried other sizes and designations but the only one that misbehaved is size box when 10-32 UNF is selected.  Re-selecting size makes the designation revert to 10-24 UNC.  Playing around with the selections can get the boxes to read correctly but they are unstable and unpredictable.  It is unclear if the model is changing or just the numbers displayed in the size box are incorrect.

[Phil.E]

Hi,

I can't reproduce this. Can you please make a video using Autodesk Screencast so I can see if I'm missing a key step?

" Playing around with the selections can get the boxes to read correctly but they are unstable and unpredictable.  It is unclear if the model is changing or just the numbers displayed in the size box are incorrect."

In response:

• When you say unstable and unpredictable, are the boxes changing in other ways than what you describe?
• To tell if the actual size is changing, just watch the model, you should be able to see the difference between #8 and #10 threads with your eyes as the model changes size to make the different threads. If it's still not clear, try using "measure" from the Inspect menu. Please let me know what you find.

Thanks,

[Anonymous]

Phil,

[Phil.E]

Yes?

[Anonymous]

Sorry Phil,

I selected reply on your email but all that got posted was my salutation.  Let's try again.  I attached the file that demonstrates the behavior mentioned in my original post.  If you right click the thread feature in the progress bar and select "edit feature", the edit window will appear.  The size box will read #8 or #10.  Keep in mind that the size box changed from #10 to #8 the first time I selected 10-32 UNF when originally creating the feature.  Now, anytime "edit feature" is selected and the edit window appears, it is a toss up whether the #8 or #10 appears in the size box.  I'm not sure but I don't think the model is changing just the size box.  If the size box reads "#8" and I reselect "#10" the designation changes to 10-24 UNC.  Re-selecting 10-32 UNF will make the size box change to #8.  Clicking OK and re-selecting "edit feature" may show #10 in the size box.  This behavior is confusing and erratic.

[Phil.E]

Got it, thanks.

For now, can you try using the Hole command to make threaded holes? I'm finding that the problem does not exist if you make the threads at the same time you make the hole.

[Anonymous]

Thanks Phil,

I tried your suggestion.  It does work but I found that there was no control of chamfer angle.  82 degrees is the only choice.  Another limitation is the pilot hole diameter.  The hole defaults to .151 in. and there is no ability to change it.  When designing for manufacture, it is useful to be able to specify a pilot hole size that matches the percent thread when cutting or, if rolling the thread, matches the size needed for different materials and depths of thread.  Any chance of getting an enhancement/ bug fix in the near future.

[Phil.E]

OK.

FYI: Fusion defaults all threaded holes to the thread minor diameter. When you "drill" your own hole, and then add a thread, the "drill" size is discarded.

To illustrate: "Drill" a hole Ø.25 , apply a #4 thread to it. Fusion will resize the hole.

If you intend to use other means to make machined threads, you have to adjust for that on the actual machine by picking your favorite drills for your favorite threads. CAM will not read your "pilot hole" size from the hole in the model.

Thanks for the response, I've forwarded your comments and experience to the team working on threaded holes.

[Anonymous]

I'll settle for a bug fix on my original observation.

[Phil.E · Accepted solution]

Sure, that you are entitled to settle for. I just didn't want you to have the wrong idea about drill sizes as related to threads in Fusion.