topic join problems in Fusion Support Forum

join problems

Anonymous — Fri, 27 Sep 2019 04:16:20 GMT

I'm trying to create joints so that the pushrod, servo horn and control horn move in unison, moving the elevator up and down. The frustrating thing is that I was able to get it to work before but I cant seem for the life of me to get it to work! I looked at my previous design, followed step by step and when I try to move it, nothing happens. If I remove one of the joints on the pushrod, the servo will move as well as the elevator individually. Please someone help me before I punch a hole though my monitor!

Thanks in advance,

Simon

Re: join problems

TheCADWhisperer — Fri, 27 Sep 2019 05:34:43 GMT

Do you have design history turned on?

File>Export and then Attach your *.f3d file here.

Re: join problems

davebYYPCU — Fri, 27 Sep 2019 11:21:19 GMT

Revolve Joint on elevator hinge, to Stab

Revolve Joint on Control horn, to Pushrod.

Revolve Joint on Pushrod to Servo arm

Revolve Joint servo arm to output shaft. Set Joint limits to 60 degrees each way.

If this system locks up, all the shafts (Joint ) axis are not aligned.

servo parallel to fuse sides, the obvious culprit, and both pushrod ends will need ball joints.

Might help....

Re: join problems

Anonymous — Fri, 27 Sep 2019 12:40:54 GMT

It's my own design of an airplane so that's why it might look a little funny. 😉

Thanks,

Simon

Re: join problems

jeff_strater — Sun, 29 Sep 2019 01:09:21 GMT

@s.brooks2020 - I was able to get the mechanism to work by editing Rev18, and changing it from a Revolute to a Cylindrical joint type. Sometimes that kind of edit can free a stuck mechanism if there is a bit of mis-alignment between components. Screencast coming shortly

Re: join problems

Anonymous — Fri, 27 Sep 2019 19:16:39 GMT

wow thank you so much Jeff for taking the time to look at the model! Now knowing to use a the cylindrical helps a lot, but if you do show me the screencast that would help a lot as well.

Thank you!

Simon

Re: join problems

Anonymous — Fri, 27 Sep 2019 19:21:35 GMT

Hey Dave, thanks for the input! I did try the ball joint and it does seem to work well. For my purposes it's perfect for what I need but I'm also interested to learning more on how the joints work so I'll look at Jeff solution as well.

Thanks!

Simon

Re: join problems

jeff_strater — Fri, 27 Sep 2019 20:59:34 GMT

never sure if a screencast is going to work or not. Trying again. If it fails, here is the link: https://knowledge.autodesk.com/community/screencast/2ee3d311-d8a2-4bc5-954a-e82344e3df66

Re: join problems

subversivespeed — Sun, 29 Sep 2019 01:10:20 GMT

Because often a joint may be offset or become offset somehow, I often use the ball type joint just to ensure it won't jam up.

Re: join problems

Anonymous — Sun, 29 Sep 2019 01:46:43 GMT

Alright, I'll keep that in mind. 🙂

Thanks!

Simon

Re: join problems

Anonymous — Sun, 29 Sep 2019 01:58:27 GMT

Thank you Jeff for taking the time to capture and upload this video! I didn't know exactly where to put the cylindrical joint, but with the video it makes it very clear.

Thanks again!

Simon