Screw motion simulation

[joergen_nilsson]

I got the screw motion correct using motion link, but why does the screw only rotate one lap when simulating the motion?

[jhackney1972 · Accepted solution]

The Revolve motion limits cannot be set to more than 360 degrees.  Normally this is not a problem until you have a screw application then it gets to be a big problem as you have seen.  The answer is to add another joint, I use a Slider joint, and using a motion link between it and the Revolve, in your case a Cylindrical joint, to drive the screw the number of revolutions you desire.  The problem with this method is the default Joint animation speed is too high so you have to change it also.  You do this using a Text Command.  I show you how to enter this command into Fusion but I failed to mention that you must select for TXT entry.  The below graphic will show you the switch which is located at the far right hand side of the Text Command dialog box.  The text command is Fusion.JointAnimationTime and then a space followed by the number of seconds.  In my video you will see I used 20, Fusion default is 3 which is entirely too fast.  This variable will automatically reset to default the next time you restart Fusion.  I broke all links in your model so I could return it as a F3D file so you will not have to upload it, just hope it.  As you can see in the video you drive the model by right clicking on the Slider joint in my hidden added assembly and choosing Animate Joint Relationships.

By the way, I think you have the pitch calculation a bit wrong in your screw motion link.

[joergen_nilsson]

Many thanks, that was a great workaround.