Folding Panel and Joints help!

[Anonymous]

Hello, many thanks in advance for your help. I'm trying to build an equilateral triangle panel that fold in towards the centre; as you can see I have three spokes that will fold in towards the centre, and then each third of the triangle is separated into two panels which are hinged on each side. I've started with just one third, and everything appears to work, but as soon as I connect the two panels together at their centre point the whole assembly stops being able to move. Does anyone have any idea why this is? I'm quite new to fusion 360 and can't seem to figure this out.

Here's the project file (i think) http://a360.co/2jbe8qs

Many thanks for any help!

Best wishes,
Eden

[SaeedHamza]

To be honest, I don't think that Fusion has the abilities to accept such movements

@jeff_strater

@TrippyLighting

What do you guys think? is it possible?

Regards

[Anonymous]

Hi Saeed, thanks for your reply, although there is nothing particularly special about this movement- it is not so different from a four bar linkage? Moving the two outer bars affects the movement of the two inner bars (or in this case panels)..

But then again I am having no luck trying to get it to work so perhaps it is not possible. Can you recommend a CAD program where such motion might be possible?

Again, thank you for your help!

Cheers,

Eden

[TrippyLighting]

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@SaeedHamza wrote:

To be honest, I don't think that Fusion has the abilities to accept such movements

@jeff_strater

@TrippyLighting

What do you guys think? is it possible?

Regards

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Yes, I do think that theoretically this should be possible and I've experimented some without getting it to work. I believe Fusion 360 joint solver is having a hard time figuring this out.

1. I deleted the contact sets. These would most certainly lock this design up and prevent the joints from doing their jobs

2. I deleted the motion links. At the time these are created in the timeline they seem to make sense, but in a fully fleshed out design with all joints in place I believe the would get in the way.

3. Also the hinges only need one revolute joint. The other revolute joints can be converted into a rigid joint. That was the hinge is still functional but it will reduce the load on Fusion 360's joint solver.

Having done all that I can see the geometry "shivering" when dragging around on it attempting to see if the joints behave as expected. But it never really moves.

[TrippyLighting · Accepted solution]

@Anonymous After having had a slight success in getting it to move slightly I designed my own quick mockup. This works fine in Fusion 360. My guess is that your design lacks precision somewhere but I don't have the time to look at it in more detail at the moment.

[jasonhomrighaus]

The difference here is the pivot point of the leading edge, in your model they are centered at the pivot point, but in the original there is a joint outward slightly that causes the whole thing to bind up.

[jasonhomrighaus · Accepted solution]

Ok,  The issue is in your pivots.  the distance at the center due to the location of your forward pivot points, causes the distance between the inner edges to change.  I added a pair of rotation points and a slider where your old center pivot was and now you can see how it is behaving.  i will tinker with it some more to set the pivots in the right spot

[jasonhomrighaus]

There are a lot of geometry issues in there as well. that is def not helping

[Anonymous]

Hi Peter,

Thank you so much for your help and taking the time to try and suss this out - the file and video you attached are super useful in letting me see how this would work, and learning more about how to use fusion 360. 

Cheers!

Eden

[Anonymous]

Ah yeah, thank you as well for your file, i can start to understand where i've gone wrong, and how to improve for next time. 

Thank you!