Odd behavior with revolute and slider mechanism

[Anonymous]

Hello fellow Fusion 360 users and support staff,

See picture below, I have been trying for two days (countless hours) straight with all kinds of permutation and combinations of aligning components before assembling joints and when do the final assembly of the slider, I get an error.  I am loving Fusion 360 but I am feeling that this last unpredictable behavior is leaving me rather stranded and hopeless when I was soooo close to success.  Somehow I had managed previously to assemble this very same mechanism and had it working, but now I can't figure out (after moving and reassembling components) what is causing Fusion 360 distress in calculating geometries for the proper alignment of coincident lines of intersection.  As this is a rather odd and somewhat unpredictable I would not mind sending an attachment of the "f3d file" to anyone that might be able to assist.

Regards,

Emil Rivas

[schneik-adsk]

try changing the revolute to cylindrical joint type. does that help?

[Anonymous]

Hi,

No, have tried that as well, and gives me the same message. It feels as if
Fusion thinks the joints and/or degrees of freedom are unsolvable almost
like overconstrained or something similar. Even when I align the
components precisely where they are aligned appropriately, it still
responds the same way.

-Emil

[NicolasXu]

Hi Emil,

I would like to look into the problem. Can you attach the model (.f3d file) to the forum? Or you can email me if you prefer (lixiong.xu[AT]autodesk[DOT]com). You can save the file as an f3d file using the Export Archive tool in the application menu.

Best Regards,

[Anonymous]

Was a solution ever found for this?  I'm having a similar issue creating four bar linkage that's also connected with concentric cylinders to simulate a stretching spring.  I can create all the necessary joints, but the assembly won't move when they are all active.

[NicolasXu]

Hi judah,

Can you share me your design so I can take a deeper look? You can either Export the entire file as .F3d format or Share Public Link with me by enabling the download permission. Both commands are available under the File menu.

My email address is lixiong.xu[AT]autodesk.com

[Anonymous]

Unfortunately, I never heard back from Autodesk on this one.  

[NicolasXu]

Hi Emil,

Did you once send the design file to somebody? Sorry but I didn't get your email. It was probably been mis-sorted into the Junk email box.

If you still see problems regarding this topic, would you share the model and post a message here so I can look into it?

Best Regards,

[NicolasXu · Accepted solution]

Hi Emil,

I got your file. It seems Community Mailer cannot handle the reply with attachment somehow.

I looked into the file. The Joint conflict is actually caused by the distances are different for the top gap and the bottom gap. See the picture below. If we add Revolve joint at the bottom gap, and select the side face to align. The difference will cause conflict.

We can either use a Cylindrical joint to allow the difference, or define the Joint origin at the middle plane. Please refer to the screencast below for details.

Hope it helps. Please let us know if there is any questions.

[Anonymous]

Wow; Nicolas, never would have thought of a size deviation being there or it causing the problem.  Thanks!

-Emil