Lucien,
While I agree with Jan completely, you also have two more alternatives:
- you can use the built in transmission blocks.
- you can also make a Modelica block that behaves like the scissors mechanism (since you have the equations for it).
As you state -- you only need one dimension, the scissors block is merely a transmission ratio between the input and the output. You can successfully model it as a lumped transmission using built-in components. For example, look at idealGear and idealGearR2T. You can model the scissors mechanism as a transmission.
Secondly, you can make your own translation block that has the behavior you need. It is a simple model (probably two equations). The advantage of using the 3D mechanics library is you get 3D animations. The disadvantage is you need to traverse the relatively steep learning curve and get your dimensions right in 3D.
Personally I would start by getting something running in 10-20 minutes by using the built in transmission components (especially since you say it is massless so the changing inertias will not need to be modeled). I would show you a simple example you do not indicate the inputs/outputs. For example: Are you using a motor? or. linear actuator? or Are you just specifying a force or torque or a motion profile on the input? What is the geometry? etc.
Regards,
Neil
