Long stacks of High-level mates...

caradon

I like the concept of high-level mates in Onshape. They are fast to set up, robust and intuitive.
However, they are not ideal in all situations.
One such situation is long stacks of mated parts.

In attached example, I want to rotate the selected tube, with the holes face up.
The logical procedure is to 'Reorient secondary axis' for the Fastened mate that connects this tube to the first connector part.
However, if I then Solve/Apply the new orientation, all components that are mated to this tube downstream are rotated as well. So, I would need to go to the mate that fastens the tube to the second connector and do another 'Reorient...' to get the original orientation back.
This seems cumbersome to me. And in these situations, classic low-level mates (IF properly applied!) would not cause these components to rotate.

How are you Onshape guys thinking of handling part reorientations without affecting assembly structure?




Dries

billy2

Dries, is the main structure fixed in any way?

Sounds like both parts are free to move.

caradon

@bill‌
The assembly (I should say: all parts) has 0 DOFs.
Btw, is there a way to check DOF in assemblies? I usually end up dragging/pulling stuff to check if everything is fixed...

The problem is that any part (or collection of parts) that is fastened to the part I want to reorient, gets rotated along. This behavior fits perfectly in the logic of the high-level mates, but in this situation it's not what I want.
In this situation, ease of use (of high-level mates) is getting in the way of design intent. I don't want and never intended those parts to rotate.

Dries

billy2

I haven't built up a large assembly yet, so I'm interested in your findings.

I'm trying to look at your "quadro construction kit" but it's not part of the big tubes collaboration. Is there a reason why it's not part of the collaboration effort?

I'm really interested in how you built this assembly. Is it easy for an outsider to understand? Could I add to your assembly structure without destroying it?

Sounds like they need to accelerate the assembly, this would show the DOF. With all the online games out there you'd think hooking up a physics engine would be simple. Accelerations in the x, y, z would show most DOF and then angular accelerations for rotating member who's geometric centers match the center of gravity. I suppose you would want to render cylinders and cones with checker board patterns so you can see them spinning. I'm going to hit "ctrl-u" and submit this as an enhancement because I think you are onto something.

To solve your problem, is there a way to sub group your assembly so you are not trying assemble a million components?
Could you construct sub-assemblies and then assemble these into a higher tier?

My little assembly with 3 mates:
   

billy2

Dries-

I submitted this using usersnap and received a ticket #1112. 

caradon

@bill‌

"I'm trying to look at your "quadro construction kit" but it's not part of the big tubes collaboration. Is there a reason why it's not part of the collaboration effort?"
It IS part of the collaboration effort! Anyone can view it, make a personal copy, copy parts from that document into the ‘big tubes’ document.

"I'm really interested in how you built this assembly. Is it easy for an outsider to understand? Could I add to your assembly structure without destroying it?"
I still think the structure is fairly robust and easy to expand on. Why don’t you save a copy for yourself from the public doc? You can have a swing at building your own huge toy.  

"Sounds like they need to accelerate the assembly, this would show the DOF."
I would actually prefer just a simple “Fully defined” message if there is 0 DOF.

"To solve your problem, is there a way to sub group your assembly so you are not trying assemble a million components? Could you construct sub-assemblies and then assemble these into a higher tier?"
I’ll experiment!

Dries

billy2

Dries-

"quadro construction kit" 
Am I missing something?:


Can you please help me find your assembly?


Why don’t you save a copy for yourself from the public doc?
Oh I'm planning on it, I'm really interested in how convoluted these assemblies can get. Thanks for doing this Dries, I've been wanting to dissect someones assembly and see how much better mate connector are vs. constraints.  I'll share with you my thoughts and findings when I tear your assembly apart. Maybe we'll both learn something new.

I would actually prefer just a simple “Fully defined” message if there is 0 DOF.
That should be easy, D-cube solver should be reporting this. I would like more because assemblies can be so difficult to understand especially if you didn't create it. 

Also, that's no fun, OS please add a physics engine to assemblies.

I’ll experiment!
Please branch these, I'd like study your versions and thought processes on how to put assemblies together. I'll do the same on my end and share with you.

caradon

@bill‌
No, no, sorry about the confusion. It's just the public document. You can actually make a copy of any public document to your own personal space. Then you can freely do edits. That's what I was referring to.
I think you can also copy 'n paste Part Studios from one doc to another?

Dries

lougallo

@DriesV yes copy/paste is an option.  We are working on organization and being able to work with large models and trees of data.  More refinement to come as we iterate.   Have you tried the play button in various mates?  Are you wanting to see if there are any DOF in a specified assembly?  I will add you to this as well.

andy_morris

I'd like you feedback about mating, in particular about the "solve" button in the mate dialog.

At the moment we don't solve the assembly mates fully when you position two mate connectors together. When you OK the dialog or hit "solve" we fully solve the assembly mates. What are your opinions on this behavior?

Are there times when you want to defer a solve of multiple mates until later?