SketchUp 8 tolerance limitations

bagger05

Hi guys,

I came across this problem when trying to dimension something in LayOut and saw that when drawing in inches you can't dimension in a tighter tolerance than 0.01". I was digging around to find out what was going on with that, and came across this post from Google employee John Bacus:

@unknownuser said:

As you can imagine, we do care quite a lot about precision/accuracy in LayOut's dimensioning system. In fact, we limit the precision for decimal inches to .01" because we can't certify that values in the thousandths of an inch are correct in all cases. For the majority of our users, this isn't an issue– they are doing either architectural or furniture scaled work where thousandth of an inch are just not relevant. But I can easily understand how unsatisfying this is for those working at a machinist's tolerances.

Unfortunately, this isn't just an issue in LayOut. SketchUp can't really work to .001" precision either. As you approach entities of .001" in length or less, you'll find that faces in the model won't close and SketchUp will begin reporting validity problems. The only real solution to this is to scale the entire model up by some multiplier.

nspies: If you haven't already found it, you can limit the precision of your dimensions in LayOut by choosing 1/8" from the "Precision" menu in the Dimension Style panel.

hope this helps-
john

The dimensions in LayOut is not that big of a concern for me, but I am a little worried about his statement that SU won't work to 0.001" precision and once you go that small things don't really work right.

When I go to WINDOW > MODEL INFO > UNITS, I am able to select tolerances MUCH smaller than 0.01", and when I import items as .DXF files everything seems to measure out to the dimensions that they were originally drawn in (originals were drawn in TurboCAD).

So my question is this: Has this issue has been resolved with the update from SU7 to SU8, or is drawing things to 0.001" tolerance still unreliable as John stated in his comment?

I know some people use the workaround where they draw everything in feet and then scale down by a factor of 12, but obviously I'd like to avoid doing that if I can.

Thanks in advance for your help.

Travis

mitcorb

I have seen no evidence that sketchup8 is any different than earlier versions with respect to the .001 precision threshold. Regularly, the reply to most similar inquiries in this forum is the same--and from some of the most experienced members and moderators. Scale up your work x 10, 100, even maybe 1000 times. Then, when you are finished, scale it down.
One technique used and recommended by DaveR is to make a component, copy it and scale it up in the same working file for doing intricate small faces. Scaling a component instance does not affect the original instance, only the mesh editing is affected. When you scale back down, the tiny faces remain intact.

Dave R

I don't scale the copy back down, though. I just close it after editing it and delete it. The original at its original size remains with its faces intact.