topic Component wont move. HELP! in Fusion Design, Validate & Document Forum

Component wont move. HELP!

jamesf2SRYX — Sun, 07 Aug 2022 13:15:02 GMT

Hi All

Could someone have a look at this model and see if you can see why i cant move the component called "Main bar". Its supposed to rotate around the arm attached to the motor but it moves with the motor. Just occasionally it seems to move correctly. I think its something to do with the linked motor? Driving me up the wall.

thanks. https://a360.co/3Q8i2Oy

Re: Component wont move. HELP!

jeff_strater — Sun, 07 Aug 2022 15:49:30 GMT

I assume that you are trying to do this by dragging the Main Bar component interactively. The problem is you have two revolute joints (Rev4, and Rev8) acting on related components. There is no priority on joints in Fusion, they are all equal. So, when you drag Main Bar, either motion is equally valid - either Rev4 moves or Rev8 moves. You can see, if you use Drive Joint on Rev8, it does function correctly, so there is nothing wrong with your joint system. There are just too many degrees of freedom in the system. FWIW, the same thing would happen in real life - if you built this system, and if you dragged Main Bar, you could get either motion. In the real world, imagine if you had tightened the fastener just a bit too much between Main Bar and Shaft, you would get the same motion.

Just curious: What problem is this behavior causing for you?

Re: Component wont move. HELP!

jamesf2SRYX — Sun, 07 Aug 2022 16:18:03 GMT

Many thanks for the advice. I scrapped the model, did it again and it did work this time. The problem was that it wouldnt revolve on the shaft. It does now. Here is the model currently if you want to have a look. Many thanks.

https://a360.co/3oYem67