AnsweredAssumed Answered

How to make two rotating assemblies in series?

Question asked by Adrian Ghansah on Jan 17, 2021
Latest reply on Jan 18, 2021 by Adrian Ghansah

Hello, I have a simple assembly consisting of two parts, where each part is a simple box. The two parts are stacked on top of one another and the top part can rotate relative to the bottom part which is fixed.


Two box assemblies:

First assembly

My problem occurs when I try to import two of these box stack assemblies into a new assembly and try to place them on top of one another.

I use the ProfileCenter command (between blue and green) to connect the two assemblies so that I get four boxes stacked on top of each other.


What I want is that if I rotate the lower assembly (the blue), that both of the boxes belonging to the top assembly (green and red) rotates together and if I rotate the top box (red), only that one will rotate while the base (everything under) is standing still. The yellow box is rigidly fixed to the ground.


What happens is that if I rotate the second box (blue), then only the blue and green box will rotate, while the yellow stands still (as it should), but the red box also stands still, even though its base (green) rotates. 


If I rotate the red box it rotates alone as I wish.


I am therefore wondering how I can make the red box rotate together with its base (green), whenever the green base is turning.


I understand that I am going about this the wrong way, however I have not been able to figure out how to solve the problem. I have tried a lot of different things and tried looking it up, but I had problems finding any relevant answers.


Thank you for all your help.



The actual reason as to why I want to do this is because I am modelling a robot arm where two motors are connected in series, that is one motor is connected to the shaft of the other. I therefore want the outermost motor to rotate together with the innermost, but not vise versa. 


I added the CAD files for the box example.