Mate problem

stephan_wörz

Translated from German by Google

Hi,

Is there a way to mate individual sub-assemblies in such a way that they are controlled as a function of the overall state of an assembly.

How can I create a symmetrical structure?

The distances between the individual star knobs should always be the same.
...even if the cylinder diameter varies.

https://cad.onshape.com/documents/fdfb1508843e05f3c93df0dc/w/8068883a45d7003adfc69d5e/e/e9cb987ed8ae01cbf450d91c

 

3dcad

It's pretty heavy calculation but you can do it with linear mate to sub-assembly and to main assembly

3dcad

No wait, you need something more.. but I think linear is a step to right direction, don't have enough time at the moment:
https://cad.onshape.com/documents/a97a3fe09b3f243b643e2db7/w/8b371d600f4a7f0def651f5d/e/a13e9e30a13bbe2d230ea747

owen_sparks

How about:-

(a) Reference sketch that is a hexagon with a mate connector on each point,
(b) Knobs fastened to those mates above,
(c) Slotted bars as tangential or pin to the knobs
(d) Extra mates at mid point of sides of reference sketch with revolute to mid point mates on the bare (to keep them centered)

Owen S.

owen_sparks

Here is a very rough go at it, other people will have better methods I'm sure.

https://cad.onshape.com/documents/55993e6511335716b1053a43/w/8029f9638374ddfdc5e9e94c/e/f3490d686401d59adf4a12bc  

It uses the layout sketch as proposed above to mate the 6 knobs.  It also has mid point mates for two bars (one high the other low so they don't pass through each other.)  These are then patterned in the assembly to get the other bars.

The knobs don't sit in the slots but I was concentrating on a method that would rebuild when the cylinder diameter was changed.

I bet @philip_thomas could do something better with a third of the actions

Hope that at least gives a few ideas,

Owen S.

stephan_wörz

Thank you very much!

...I will try to understand and implement the proposals.

Stephan

owen_sparks

No problem, please ask if it doesn't make sense, and be prepared to do it again when somebody proposes a better method!

Cheers, Owen S.