Thread and revolute joint

[Anonymous]

Hi community!

I am trying to build and simulate a lead screw using Fusion 360. Having studied AutoDesk manuals and a bunch of youtube videos I seem to understand the way it should be done, however doing this in practice turns out to be not so straight forward. 

I have built a rod and applied M5x0.8 thread to it. Then I have build a moving platform with a hole in it with the same M5x0.8 thread. Then, in order to prevent this platform from rotating with the rod I have made a cut in it's bottom and another component. And finally, to fix a rod to something I have created a box and attached one end of the rod using revolute joint. I have few contact sets: between rod and moving platform, between rod and a box. I am able to rotate the rod itself, it rotates inside a hole of the platform, however the platform doesn't move. 

First thing I though when I've done this is the threads or hole diameters are different. However, having tried different options it appears they are correct. I have also made sure both threads are built with "modelled" option on.

Before I bang my head against this, could you please advise if what I'm trying to do is possible in Fusion 360. And if someone have done something similar, I would appreciate advises. 

[TrippyLighting]

Please share your design. Either by exporting it as a .f3d file or using the share function in the data panel.

[xander.luciano · Accepted solution]

Hello! Welcome to the forums! 🙂

From just quickly reading over and looking at your setup - it looks like you are almost there! Just make sure the slider joint isn't attached to the rotating lead screw or else it won't work. This is because a slider joint locks the rotation together.

Did you already add a motion link to the slider joint and the revolution joint? If not, add one, choose the slider and the revolute joint, and set the settings to .8mm per 360 degrees of rotation (to match the thread pitch):

After that it should work! See the attached file for how I set it up.

Hopefully that gets you started down the right path and not banging your head on your desk!

Let me know if I can help with anything else!

Best,

[Anonymous]

Thanks for the suggestion. I had two problems: missing motion link and enabled contact sets (which seem to be redundant in this case as joints already block moves in not wanted directions). Once I have established the link and disabled contact sets, everything started to work like a charm. 

[xander.luciano]

Awesome! Glad you got it all figured out man.

Once you get further along on this, I'd be interested in see how the end result turns out!

[TrippyLighting]

At the moment I'd stay away from contact sets. They are incredibly power hungry and as assemblies get more complex seem to create more problems than they solve.

Just my experience with a number of assemblies that I helped other users with her on the Forum and offline.

[Anonymous]

New to Fusion 360.  I've studied the example and don't see what prevents the slider from revolving.  Is there some sort of constraint or setting that I'm missing?

I am working on a leg vise model for a workbench with grounded leg a screw "slides" in.  Revolving the screw in the chop opens and closes the vise based on motion link.  Unfortunately, the chop spins wildly as well when animating the motion link.

[Anonymous]

Current file.

[phoshovsky]

The solution made by Xander Luciano is correct. I have attached my (finally!) working model. My mistake was making a slide joint between the shaft and the collar that slides on the shaft.  The only joint on the shaft is the revolute at EndBlock. Note that right click on the Slider 24 and choosing animate joint relationships shows the correct travel of the collar and the slide block. When you right click on Revolute27, the motion is still possible but much more limited. 

Many thanks to Xander Luciano.