topic Re: Drag chain freezes the other parts from moving. in Fusion Design, Validate & Document Forum

Drag chain freezes the other parts from moving.

infoY5TP8 — Thu, 18 Oct 2018 05:41:27 GMT

So I'm designing a dual X 3D printer and I want to add a drag chain to the design.

So I added a Rigid to one side of the chain to the X train and the other side I grounded.

then all the middle pieces have revolute with a min and max degree of 0 and 30 degrees.

if I take the real Drag chain, to test if works but my design will not move the parts anymore.

all is frozen.

Any ideas Why this is not working or am I doing something wrong on impossible?

Re: Drag chain freezes the other parts from moving.

chrisplyler — Thu, 18 Oct 2018 14:17:22 GMT

It doesn't seem impossible. You would have to attach your .f3d file here for use to examine it and figure out the problem.

Re: Drag chain freezes the other parts from moving.

infoY5TP8 — Fri, 19 Oct 2018 07:14:08 GMT

Thanks for the reply,

Will this file work

Re: Drag chain freezes the other parts from moving.

chrisplyler — Mon, 22 Oct 2018 12:26:49 GMT

Well...I can't figure it out. The slider works as expected. Each link in the chain works as expected. The entire chain works as expected, right up until you make the final joint to connect the second end of it. Then it locks up solid.

@jeff_strater any ideas?

Re: Drag chain freezes the other parts from moving.

TrippyLighting — Mon, 22 Oct 2018 20:37:20 GMT

This isn't going to work with the "normal"tools in Fusion 360. I've only seen one user succeed at it and he used one of the Fusion 360 API's to program the functionality. It's just too many joints chained together. A higher performing computer might be able to deal with more joints but ultimately this will not work.

Re: Drag chain freezes the other parts from moving.

jeff_strater — Wed, 24 Oct 2018 00:46:34 GMT

I suspect that @TrippyLighting is correct - that many chained joints will stress Fusion's assembly solver beyond the limit. I looked at the design. The first thing I noticed was that each of the Revolute Joints has a Rest setting. I thought that might be complicating the solve. But, I went through and removed the Rests from each of the joints in the chain. It didn't help - the chain is still locked up with that last Revolute joint to the grounded component at the top (zmount block). I'll look at it a bit more as time allows, just to see if I can free it up a bit, but I'm not too optimistic.

Jeff

Re: Drag chain freezes the other parts from moving.

chrisplyler — Wed, 24 Oct 2018 13:08:40 GMT

After turning off the visibility of all components not critical to this particular issue, and prior to making that last joint, the chain moves/flexes easily as expected, with only a very slight stutter on my screen due, I assume, to the solver doing it's calculations. I find it a bit suspect to think that just "one more joint" puts it over the solver's limit and locks it up completely.

Re: Drag chain freezes the other parts from moving.

davebYYPCU — Wed, 24 Oct 2018 20:39:13 GMT

Prime symptoms for Cylindrical, then?