I had to waste hundreds of hours adjusting all the time until I found out what the problem was: the metric system is not correct.
The points do not connect! I suspect that instead of connecting the center of the points it connects to the RIM of the points.
Millimeters are important in the metric system but SketchUp does not seem to understand that system. I would not be able to design a delicate piece of mechanics! I can’t even design a house without running into problems.
It looks to me as if your setup is what’s flawed. There’s nothing wrong with the metric system used by SketchUp. It appears your model, whatever it is, should have been modeled at higher precision than you have selected. You could increase the precision to be higher than you can measure in a practical way in real life. You might also consider turning off Length Snapping. These options are yours to set.
