@unknownuser said:

Can you show an example, I can't reproduce this.

I'm sorry about that, it seems I didn't try enough. There is no difference between the axes. It irritated me that the moving direction of a piston or slider is opposite to the direction I choose with the mouse when positioning. For example, if I put a slider joint on the corner of a box and drag the mouse to the positive green direction it will move only to the negative direction.

@unknownuser said:

I can't change it because it could break compatibility with prior models, but I can make it to evaluate everything in the control box. For example, if you write 100mm it will turn it to 3.93.

Maybe this would help a little bit. To put the units besides the input boxes would be great and help people also. Maybe you know that a Mars orbiter crashed in 1999 due to falsely used units. I assume no one uses SP to constructed actually flying space ships, still it feels good to know what units one uses.

I found this thread which gives some information about units in SP:
http://sketchucation.com/forums/viewtopic.php?f=61%26amp;t=53209

A world scale factor of 1.0 and gravity of 9.81 (m/s²) seems to be suitable if using metric units.

Maybe this thread is of interest for you also. Looks like SP's author asked this question:
http://newtondynamics.com/forum/viewtopic.php?f=9%26amp;t=4684

First of all I want to thank you, Anton, for this great update! Finally someone who takes care of this awesome plugin.

I don't remember if previous versions of SP also showed this behaviour: Positive values for the blue axis (e.g. a piston slider) move things down, in negative direction, whereas positiv values for the green or red axis move things in positiv direction. This irritates me. A bug?

The other issue I want to address are units. I always use metric units but SP converts them in imperial. For instance, when I position a piston and give it a length of 100 mm (by typing 100 a hitting enter while drawing) the UI max box shows a value of 3.93... which are inches. When I type 100 into the max field, the piston moves 100 inches, not millimeter. I would appreciate it a lot if SP used the units as set in the model settings window. Actually all boxes in the UI should be labeled with the unit expected (the unit set in the model settings). For example, what's the unit of density? What's the angle unit? Radian or degree? And Strength? This would make things a lot easier.