topic Re: Joint constraint problems in Fusion Design, Validate & Document Forum

Joint constraint problems

DANIEL.HUNTER428 — Thu, 13 Jul 2017 14:30:56 GMT

So i'm having several issues with joint assemblies, esp revolute joints. In the past they have worked OK but it just seems that the behavior is buggy now. More than likely i'm constraining it wrong, as in the past the order that it you apply them could result in the assy locking up.

Firstly i have two gripes with the revolute joint; When you apply them they rotate the part. It was modeled in a specific location, why does it have to set it to 0, 90 etc. Usually the angle is pretty arbitrary most times and the result is undesired movement of the assembly. Second some of them seem to be driven by other joints and there is no reason they should be linked.

My main problem atm is that i'm fully constraining an assy that consists of a hatch, 2 hinges and an actuator. I can get it to work but 2 moves and it will completely lock. No conflicted joints and a method that i have used successfully in the past. I had this assy working but somewhere along the way parts were moved (i didn't move them, Fusion did!) and the final alignment was out. I suspect it was the rev joint activating another one and I didn't notice. So i had to delete most of the joints and start over. Sometimes i'll get conflicts, sometimes it wont but gets locked and sometimes it worked with limited movement. Absolutely no consistency.

Also, the hinge is a proven design and there is no physical reason the actuator wouldn't work in the real world. I just can't get it to work in fusion. Please review the screencast. If I have to upload a model I could part out that assy. Any ideas would be appreciated, people get antsy if I can't get everything to work before sending parts off to be machined!

Thanks, Shaun

706-359-6899

design@adrenalinepowerboats.com

Re: Joint constraint problems

SaeedHamza — Thu, 13 Jul 2017 14:37:18 GMT

Hi,

Could you please attach your file

go to file > export > .f3d and attach it to your next post

Regards

Saeed

Re: Joint constraint problems

kate.raskauskas — Thu, 13 Jul 2017 14:38:58 GMT

Hi @DANIEL.HUNTER428,

Sorry to hear you're having trouble with the joints! Can you please share the assembly so I can take a closer look at the joint settings/constraints?

Thanks!

Re: Joint constraint problems

DANIEL.HUNTER428 — Thu, 13 Jul 2017 17:21:11 GMT

Kate, I sent you a PM, pls review.

An interesting note is that the constrained assembly works almost as it should when it was copied out as it's own file. The joints are hard to move and it doesn't reach the full limits of the ram but other than that its almost there. My model is reaching 400mb, i think that has something to do with it..

Thanks

Shaun

Re: Joint constraint problems

TrippyLighting — Thu, 13 Jul 2017 18:24:59 GMT

@DANIEL.HUNTER428 wrote:

Kate, I sent you a PM, pls review.

An interesting note is that the constrained assembly works almost as it should when it was copied out as it's own file. The joints are hard to move and it doesn't reach the full limits of the ram but other than that its almost there. My model is reaching 400mb, i think that has something to do with it..

Thanks

Shaun

Looks like you guys are just down the street from me as I am located in the Spartanburg area in Upstate S.C.

If you want me to take a look at your model and don't want to share it, feel free to PM me. We can also Skype if that would work better for you.