How to add constrains to the chain to ensure the robot arm is always above the workbench?

[FredTrumpSenior]

How can I add constrains to ensure that the arm is always above the workbench without colliding with it.

[Phylliade]

Hello @FredTrumpSenior,

For the moment, there is no direct way to add constraints on links positions.

However you can add a constraint in joint angles by defining joint bounds: For example you can try to add a bound for the 3rd joint (the joint before the link that goes into the workbench) to be only positive, this way the link will never be in the negative Zs:

[FredTrumpSenior]

Thanks for your kind reply