What steps will reproduce the problem? 1. Add a small, somewhat complex component or group (less than 1 cubic inch). 2. Object space interactions (gears) do not work as expected. 3.

What is the expected output? What do you see instead? Upon RUN: (1) Object should fall and/or be affected by controls. (1) Object does not fall. Object not affected by controls.

(2) Gears rotate within each-others object spaces (meshing gear teeth). (2) Gears separate so that diameters do not intersect.

What version of the product are you using? On what operating system? VistaHP, SU7, SP2/3

Please provide any additional information below. It appears small geometries do not work in SP as they also do not work in SU (known bug).

View attached file in SP2. RUN has no effect. Ctrl-A then scale by 2. RUN has no effect. Ctrl-A then scale by 2 (again). RUN works.

Also note how the gear objects will separate (repel) each-other so that they can rotate autonomously. Objects moving within each-other’s space do not work (this appears to be similar to the concave curve restriction). Extending this idea by creating “bearing” holes for gear shaft tops and bottoms to keep gears from moving causes erratic, unpredictable results.

Is there a way to allow mechanically accurate involute gear teeth to mesh?

Thank you. Mike.

I have discovered a work-around solution to point 2.

The gear shapes were "cylinder"; they are now "convexhull" which provides for clean, accurate meshing of involute spur gears without repulsion. A “powered” hinge or motor control must be joined, in opposite directions, to each gear. The most- accurate representation comes from assigning identical "accel" and "damp" values to each hinge/motor control. Note also that a “driver” gear will not affect a “follower” gear – both gears must be powered.

I vote this up, small geometries do not work.

Create a cube, 1" x 2" x 4". Group, set as box, and run. The cube will fall into the abyss as expected.

Now scale the cube by 0.5 and run. The cube will remain where it is.

Scale the cube back up by 2 and run. The cube will once again fall into the abyss.

Further experiments:

A 1 x 2 x 2 cube falls. (4 cu in) A 1/2 x 2 x 2 cube does not fall. (2 cu in) A 1 x 1 x 2 cube does not fall. (2 cu in) A 1 x 1 x 4 cube falls. (4 cu in) A 1 x 1 x 3 cube does not fall. (3 cu in) A 1 x 1 x 3 3/8 cube does not fall (3 3/8 cu in) A 1 x 1 x 3 3/4 cube falls. (3 3/4 cu in) A 1 x 1 x 3 9/16 cube does not fall (3 9/16 cu in)

The cutoff appears to be somewhere between 3 and 4 cubic inches.

Has there been any updates on this issue? This makes it incredibly difficult to create a design (to scale). If there is an update or workaround would someone post it to this thread?

I used the UI to change the density of the object from 0.2 to 2.0 and it seems to have resolved the issue

I can confirm the small geometry error. I can also confirm that density of the object has something to do with it. Changing it to 2.0 seemed to help but only for certain geometry sizes.

Is this going to be changed in the near future? Or at least addressed?

What seemed to work for me is setting "worldscale" (Top menu: Plugins>SketchyPhysics>Physics Settings) to 0.2.

Maybe someone can elucidate ?