about mating objects in assembly

darrin_jones

I've got two parallel arms that are approximately 130mm apart. I have used rotate mate to attach them to their pivot points at one end so that they sweep up and down. my problem is that when I try to rotate mate the cross bar at the arms other ends so that when arms are lifted the cross bar stays level to the base it doesn't seem to work. I get several "red" mate messages in the left window. any insights?
thanks

were is the link to the drawing if it helphttps://cad.onshape.com/documents/377974c0e0c46ddb9a7a8cab/w/853bfda50672e022d2c6453f/e/55987157fa53f0410e904cf5

viru

@darrin_jones, You are getting failed constrain because you are not defined all constrain correctly due to that intersection between part take place. You can solve your assembly by two method.
1st method:-  In place of revolute give cylindrical mate then your assembly would not show in red color but part intersection will be there.
2nd method:- Define other constrain correctly then revolute mate work for you and your assembly part is without intersection of part.
Please refer below video for more detail,

also refer below document link for your reference.
https://cad.onshape.com/documents/5880458e8e02391088bf34b8/w/347aac8e4398c8fc9665e749/e/38249d44ef45c222f9d18a24

viru

@darrin_jones,Yes you are correct you are given mates in the wrong location. You are not given as per your part dimension. Currently your assembly have  0.4 mm each side (Total=8 mm) for  "Part 1<6>",  "Part 1<4>" and "Part 1<7>". Please refer below image for more detail.

also refer below document link for your reference.
https://cad.onshape.com/documents/5880458e8e02391088bf34b8/w/347aac8e4398c8fc9665e749/e/38249d44ef45c222f9d18a24

viru

@darrin_jones, You are getting failed constrain because you are not defined all constrain correctly due to that intersection between part take place. You can solve your assembly by two method.
1st method:-  In place of revolute give cylindrical mate then your assembly would not show in red color but part intersection will be there.
2nd method:- Define other constrain correctly then revolute mate work for you and your assembly part is without intersection of part.
Please refer below video for more detail,

also refer below document link for your reference.
https://cad.onshape.com/documents/5880458e8e02391088bf34b8/w/347aac8e4398c8fc9665e749/e/38249d44ef45c222f9d18a24

owen_sparks

Hi @viru I'm amazed at the consistent excellent help you give to the community, a very sincere thanks for that. 

One small suggestion if I may?  Your videos are great, but they start playing as soon as the page opens and then run in a loop.  As such I tend to miss the start, as I'm reading the original post, and then it's not always immediately obvious where the beginning is.  A long pause at the end or a splash screen at the beginning would help here.

Cheers,

Owen S.

viru

@owen_sparks, Thank you for your suggestion in future I will definitely do that.

darrin_jones

Thanks for the answer Viru. I'm not sure I explained myself though. I looked at your copy to see what was different and discovered that even though you changed a few things I'm still seeing the red constraints. also the crossbar turns the two arms don't move. any thoughts?
thanks

darrin_jones

I ended up making a long 'axle' revolute mating it in the middle of the 'axle tube' fasten mate to one end and grouping the other end to get the movement I wanted. thanks for the help folks

darrin_jones

ah ha, on second look at your video Viru, it looks like you are showing me that there is interference or overlap where I want the parts to move when you did the section view and it also looks like you are showing me that I have the mates in the wrong locations, is that correct? as I mentioned above I got it to work but I'll have to look and see if I can use your methods to do it too.
thank you

viru

@darrin_jones,Yes you are correct you are given mates in the wrong location. You are not given as per your part dimension. Currently your assembly have  0.4 mm each side (Total=8 mm) for  "Part 1<6>",  "Part 1<4>" and "Part 1<7>". Please refer below image for more detail.

also refer below document link for your reference.
https://cad.onshape.com/documents/5880458e8e02391088bf34b8/w/347aac8e4398c8fc9665e749/e/38249d44ef45c222f9d18a24