Motion Study to Roll Up Stairs

Hello,

I have a Y shaped gear configuration with wheels at the end of each Y segment, and I am trying to animate this assembly rolling up steps. The tricky part is that in order for the Y to rotate as it needs to, I have to fix the central gear so that the others will rotate about it. I used a Solidworks motion study to apply gravity, established contact between the three wheels and the stairs, and applied a motor, but the gear configuration just rotates about itself and doesn't interact with the steps at all, let alone climb them. How can I simulate this rolling, ascending motion?

Thank you in advance for your time.

Lauren

SolidworksMotion Studies