Mirrored threaded circular pattern holes

[RC-CnC]

When I mirror a threaded circular pattern holes the mirror is missing all but 1 threaded hole. The holes mirror just fine.

[HughesTooling]

I've tried several different ways of mirroring threaded holes and they all seem to work. Even mirroring bodies that have mirrored patterns. Can you share a design that shows the problem? One thig to be aware of is if you mirror threaded holes the thread is also mirrored so the copies will have a left hand thread. Depending on the hole pattern you might be better of using a circular pattern if you can rather than a mirror.

[HughesTooling]

OK, I see the problem with mirrored modeled threads. I found it will work but you need to pattern and mirror as features rather than faces. I also found I need to use identical or I couldn't select all the features. Note, this only seems to be a problem if you add a thread to a hole rather than using the hole tool to create the hole and thread as one feature. Also found even if you use the hole tool then add the thread it will mirror OK if you window select the holes.

[RC-CnC]

 Interesting this is what I end up with

[HughesTooling]

If I change the compute type to optimise it seems to work. 

Another odd thing is if I change it to identical, mirror fails completely. I wonder if some of the problem is because the mirrored holes end up concentric in your example. @Phil.E Can you take a look?

[Phil.E]

When the holes are mirrored, the drawing shows some interesting results.

• On the mirror-result side, 10 holes are created
• The drawing shows the threads on all of them

Question: is it intended to have left-handed threads as a result of this operation?

Personally, I would never mirror anything unless I need a mirror. Mostly because the part would then be modeled wrong, assuming I don't really want left handed threads (w/hundreds of designs in production, not one with LH threads, so I'm a bit biased). This would show up in a drawing, and if not detected/corrected would result in something like the purchasing manager referencing that drawing and buying a bunch of custom LH screws, and some confused assembly staff. 

Looking for a workaround that doesn't result in  LH threads, I projected the first hole-point onto the opposite face, created the same hole twice. The hole command was kind enough to remember the settings of the first hole, so I didn't have to do much to get a second hole exactly like the first.

Then do the circular pattern, include each of the holes from either side of the part.

Ended up with all RH holes, only 6 show up in the drawing, and the same number of timeline items created. IMO, projecting the holes to the opposite face is easier than adding a plane/mirror combo. Mainly because it creates no additional geometry, eg. the construction plane.

(FUS-152599)