Revolute Mate

brian_pinder662

Could anyone give a little advice please, I am designing a spiral staircase round a centre post. I have positioned my first tread which I have fixed and
the next tread is attached using a revolute mate in order to position it in the correct position above. I would now like to remove all degrees of freedom. At the the moment I have used fixed for this purpose. Can anyone say if there is a different way to do this as somehow this doesn't seem correct although it works. Regards Brian.

bradley_sauln

You will want to use the fasten mate to remove all degrees of freedom. After you complete the fasten mate go in and edit one of the mate connectors, select the 'Move' box and put in a value for 'Rotate about Z'. As you add each step of the staircase (depending on how you do the fasten mates) you can get that spiral effect for each step.

mahir

That's a lot of manual mate adjustment. Hopefully, one of these days, OS will have advanced assembly pattern options like curve pattern, fill pattern, table pattern, derived pattern, etc.

lemon1324

This seems like a case where you'd want to define a rotated mate connector in the part studio, so that each fasten mate can just pick a top and bottom mate connector which are already rotated with respect to one another. Less manual mate adjustment (and if you want the parts to be fixed to each other, a revolute mate isn't needed and will probably just clutter the view).

john_mcclary

I think I can help you here

and @lemon1324 got it 100% right. 

Define 2 mate connectors for each step. One is at the origin, the other will be projected straight up and rotated appropriately.
now it's just a quick fastened mate for each step.

I usually do a few steps (about 90 degrees worth), then copy and paste that group, then mate that larger group.. etc.. should only take a few seconds to mate up a large spiral with this method.

You really want to stay away from hand editing every mate in an assembly. Take advantage of part studio mate connector for these repetitive tasks.

And hope and pray they release more pattern options in assemblies

MBartlett21

bradley_sauln said:

You will want to use the fasten mate to remove all degrees of freedom. After you complete the fasten mate go in and edit one of the mate connectors, select the 'Move' box and put in a value for 'Rotate about Z'. As you add each step of the staircase (depending on how you do the fasten mates) you can get that spiral effect for each step.

@bradley_sauln
This would be very useful.
I did not know about this before.

brian_pinder662

Many thanks for your  all your help, had a feeling I was not doing this the correct way.  About to start again loaded with your advice.
Best wishes & have a good day to all. Brian.

owen_sparks

@john_mcclary, so you've done this once or twice before then?

john_mcclary

owen_sparks said:

@john_mcclary, so you've done this once or twice before then?

Perhaps...

owen_sparks

@john_mcclary

Sounds like it's time for a featurescript. 

Inputs of number of steps, degrees of rotation per step, and height of step.

Not to make the steps (duplicate part instances) but at least to make the mate connectors?

john_mcclary

I find just a list of global variables works just fine.

but too bad we cant just FS in assemblies, so that is still manual

owen_sparks

Sweet, you're way ahead of me, nice job sir 
Owen S.

konstantin_shiriazdanov

owen_sparks said:

Sounds like it's time for a featurescript.

if you are talking about MC placement Parameter Pattern would do it

john_mcclary

konstantin_shiriazdanov said:

owen_sparks said:

Sounds like it's time for a featurescript.

if you are talking about MC placement Parameter Pattern would do it

is that an existing FS someone made?

konstantin_shiriazdanov

john_mcclary said:

is that an existing FS someone made?

russian hackers made it)
https://cad.onshape.com/documents/d66ea5fec7a939e866ecbd6f/w/25d8c7ecb4fba2c4e6eb34a4/e/da105d925bece61b58a66bef