Parallel mate with angular limit

les_green

Hi all, I am trying to replicate a rod end bearing assembly, and want to limit the side face of the ball to 5 degrees of movement with reference to the rod end housing side face. I am using a parallel mate, and in the limits part am putting -5 and 5 in the angular limit fields. However it seems to lock the ball in place with the faces parallel, so I am clearly not understanding the way this works.

I assumed that the parallel mate angular limit would constrain the maximum difference in angles between the two faces, is that the right interpretation, or should I be using a different mate type? 

Cheers

glen_dewsbury

Try the ball mate with limits. Sample model available from McMaster-Carr.
https://cad.onshape.com/documents/175a06e981c4096daeb1b02f/w/df3db5253b1fb2bae6bc09cb/e/b52e28a69f869ed68f2c9a98

jelte_steur814

check the axis for the angle limit. it only allows freedom of movemnt around the Z-axis, that is perpendicular to your parralel mated planes/faces/connectors. so they indeed do stay parralel by definition of choosing this mate type

a picture or link to public cad doc would help to understand what you're really looking to achieve. 

Jake_Delano

I think what you're looking for is Onshape's ball mate. This will allow you to have angular degrees of freedom for your assembly relative to the ball. For a full understanding of how Onshape's mates work, which combine location and degrees of freedom into them, check out our Assemblies learning course.

les_green

What I need is for there to be a max 10 degrees (5 degrees either direction) difference between Face 1 and Face 2

eric_pesty

les_green said:

What I need is for there to be a max 10 degrees (5 degrees either direction) difference between Face 1 and Face 2

Ball mate is what you want for this

les_green

Hi all, I tried the ball mate limit but once I click on limit, the ball moves to the position below, and if I use the reorient secondary axis, it simply moves to the other 'wrong' position with the hole aligned with the threads. Is there a way to fix this?

glen_dewsbury

Looks like you're the wrong implicit mate connectors.

eric_pesty

Expand the ball mate (in the mate feature) and edit the (one off) mate connector there to change it's orientation.

les_green

Thanks guys, that got it, much appreciated. Also helps me understand the Ball mate concept better

eric_pesty

If you want to dig deeper into some of the finer points of mates and mate connectors, here's a video series talking about stuff I don't believe is explained well in the Onshape training:

https://www.youtube.com/watch?v=HUVFq7tixKM

les_green

Thanks

I have a knock on question, having successfully made the assembly with the limiting mate. When I import that assembly into another higher level assembly, which in itself is then incorporated into an assembly. The mate limit no longer seems to be working, although the ball mate is effective. Is it necessary to repeat the mate in the higher level assembly?

Cheers

glen_dewsbury

Have you switched the menu to assemblies from parts while inserting into the higher levels? If left on part studios you will have more loose parts in all levels.

les_green

It was my error - I didn't realise that there were two instances of the assembly. I had created one when starting out to practice with, and not deleted it; that one just had a ball mate without limits. I have updated the assembly and it's all good now, sorry to bother you

Les