Problem with Ordinate dimensions

[GLJCAD]

Using SolidWorks 2014
Ive got a problem using ordinate dimensions & dimensioning to the edge of round tubes.
The base line zero is off a flat edge part & I try dimensioning to the left edge of the infill tubes as shown.
(we do it this way as its quicker for the fabricators to measure to the edge rather than guessing where the centre of the tube is)
All appears ok but if I do a rebuild the dimensions flip to the incorrect side as shown
Even if I do a convert entities to the left hand side of the tube & ordinate dimension to that, after a rebuild it also flips to the wrong side

In the end I added a sketch point coincident to the left edge of the tube & took my ordinates to that.
Yesterday that worked fine even after rebuilding, but today that too is flipping to the wrong side!
Im getting frustrated & cant see where Im going wrong or what else I could try

[GLJCAD]

Any advice please? Its happening with other drawings I have so its not just the one document

Its so frustrating, & we have lots of similar documents as we manufacture lots of railings & gates etc

[mike miller]

These kinds of problems are common with SWX, unfortunately. I believe it's the same reason that tangent mates are so "flipping" useless.

If you're using weldments, you could try putting points in the library profile at each quadrant and showing the sketch in the drawing. This would allow you to pick up a fairly stable point....

Another thing to try: create a sketch in the part file (normal to the drawing view) and place lines dimensioned from the tube centerline, which would in reality be on the silhouette edge. The reason I say this is because dimensions are actually quite stable in SWX, at least compared to silhouetted edges and tangency controls. Obviously you can now place your ordinate dimensions on the lines.

[SPerman]

You could draw a line coincident with the flat edge and see if it still behaves the same way.

[GLJCAD]

Thanks for the tips
Its frustrating sometimes using solidworks & Im glad Im not the only one with issues like this

I did try doing a convert entities to the vertical edges of the tube but again that flipped over to the incorrect side

Ill try adding the sketch points to my section profiles

[jcapriotti]

Can you upload your model files?