Attached is a clip of the actual part with the Labels showing the heights from the bottom plane. I was specifying 6.5MM all around when I built it and couldn't figure out why I was having trouble faking a face.

Then it occurred to me to check the Precision (under Windows>Model Info>Units). When I ran precision out to three decimals places, I could see some of the 6.5's were really 6.547's or 6.549's. Crap!

So now I'm thinking I need to
1) make a big Rectangle,
2) make it a Group so nothing sticks to it,
3) Move it onto the top of the part and lower it to 6.500MM,
4) Intersect Lines (with Model),
5) delete the square (the "cutting plane") and
6) delete the little trimmings it knocks off the tops of edge that stuck up above 6.500MM.

Does that sound right? Hopefully this is clearer than my octagon example.

I also included the part drawing itself (in SU 8 format) if that helps. Thanks for your help.

Kent

Hope this helps,
Matt

PS  The first image should have had the radius measured along an axis.  This was corrected in the second image.  Doubt many would notice ...

Imagine I'm drawing a hexagonal cylinder. I can't get the top to form a face, they all looked fine, no edge gaps.

I increased the precision of the tape measure out to three decimal places and, using the Label tool like a GPS measurement, now see that the wall is actually jagged.

Some of the intersections heights are 6.50MM, some are 6.547MM, some are 6.499MM, etc. Was this variance allowed because the Tape Measure (and I suppose everything elses' precision was set so loose? How to prevent this?

More to the point, is there a global way to reset the wall heights to 6.500MM? Like Select, Set Global Height, or something. A plug in maybe.

You see, the hexagon is actually a complicated part with many walls and would take hours to measure, delete, redraw all the points, then check everything one point at a time to ensure they are the same height.

As always, thank you for your help and advice.