Original Issue: http://forums.autodesk.com/t5/AutoCAD-Mechanical/Dim-Scale-error/td-p/3438607
Now, since Autodesk says it can't reproduce the bug: here's the how to do it yourself.
This applies to AutoCAD Mechanical 2012 (with SP1) and Win7. It does not apply to AutoCAD vanilla 2012.
Start: Draw a rectangle (eg. about 100x50) and fillet the corners (eg. r=10). (Because we do extrusion profiles I offset it as well - this is not relevant to the bug in particular.)
Step 1: powerdim with snap to endpoint, moving over the lines on both sides of the rectangle.
Step 2: powerdim with snap to endpoint, moving over the arcs on both sides of the rectangle.
Step 3: we now have 2 dimension with the same value
Step 4: click move and select the contour (not the dims)
Step 5: the dimension that snapped to the endpoints of the arcs will randomly decide to snap to the other end of the same arc. We did this by moving the contour, setting a new powerdim or regen etc will have the same effect.
Now, Autodesk told us to just use snap to endpoint (which, technically is nonsense) - so now then can tell us to not snap to arcs, and not do that and that... and at a certain point this ACAD Mechanical will just become useless. We are into extrusion and ALL our contour angles are filletted (minimally 0.2 mm). And sometimes there are no lines inbetween either.
Please check if 2013 has the same issue, or give me other solutions (or refunds to get our systems back to regular ACAD ). This post has no example files - to replicate the bug you just need AutoCAD Mechanical.
Additional:
- Bug is also reproducable on Win XP.
- The Win7 is 32 bit and 64 bit. Win XP is 32 bit (haven't got ACM 2012 available on a 64 bit XP machine).
- Can also do it on ACM 2012 without SP1
- I have ACM 2013 available, but can only try it in 2 days.
Additional data:
- Bug randomly appears, which makes it harder to reproduce then I posted earlier.
- But research on drawings in which it randomly appeared (from different PCs) pointed out that:
- Apparently it could have to do with "reversed" polylines.
- This adds an additional step to the reproduction of the bug: mirror.
- This makes it suddenly very easy to reproduce (tried 6 different machines, XP and Win7)
- AutoCAD Vanilla is still not affected
- Why it appears randomly in other cases is because mirror is regular workflow for symmetric objects, because we get objects from 3rd parties, because unknown (the added .dwg has had no mirror or reverse actions)
I just reproduced this error in AutoCAD Mechanical 2013 on a computer not tried earlier. (using the mirror method)
Let me repeat that jumping dimensions seriously undermine the reliability of the entire software.
The lack of reply/support from Autodesk in this matter (I have also reported this though other channels) also does not comply with the high level of service I have previously become used to.
Well, Autodesk says it has been moved to development and will be handled in a hotfix or SP.
Additionally: ACM 2012 SP2 does not help. (so that's acm 2012, sp1, sp2 and 2013 affected)
Work around so far: do not dimension to arcs and/or use mirror.
Updates:
ACM 2013 has the same bug (XP, win 7)
ACM 2013 SP1 has the same bug (XP, Win 7)
ACM 2014 has the same bug (Win 7, 😎
ACM 2014 SP1 still can't dimension in such a way that we can trust the results.
As a result I've just suggested to our reseller that we want our money back for the upgrade from vanilla to mechanical and they scrambled to find the autodesk support call they (said they) made before. More news on that later.
Again: if you cannot trust the dimensions, we may as well sketch on a napkin... and be off a lot cheaper then we are now.
Again: How can a bug like this persist since this thing was still called "genius"?
This bug has been solved in version 2015! (hurray! (and thanks))
So: solution... Use AutoCAD Mechanical 2015.
So I download 2016 (late, I know...) and try this thing again...
Simple polyline example.
The rounded rectangle on the right was dimensioned on the (endpoints) arc segments, moved, and the dimensions moved allong fine.
The one in the middle was dimensioned on the (endpoints) of the line segments, moved, no problem.
The one on the left is a mirrored version of the one on the right, dimensioned on the (endpoints) arc segments, moved... and the dimension flipped to the other end of the arc segments again.
Tried the same in 2015... and there it happens as well.
So now this bug has been kept in AutoCAD Mechanical since 2009... while vanilla has no problems.