I am relatively new to Solidworks but want to animate the movement of a mechanical latch as pictured. I have applied tortional springs on the two pivots and added solid body contact between the red latch and the angled section, and this seems to work fine (bottom left).

The problem is when I apply a motor to the moving part. As the picture shows the corner piece penetrates through the angle section above it even though I have applied solid body contact and a distance mate in the range of 0 – 1000 mm. (Note it stops correctly in the model space with the distance mate but not when a motor is added). Also it seems to slow down as it passes through as if passing through a viscous material rather than steel.

Can anybody help me fix this problem? Thanks.