mate plane to part edge in assembly

dave_banks

I find the mates to be somewhat difficult to use. Not straight forward like Solid Works or Inventor. I cannot figure out how to mate the edge of a tilted part to the face of another part. I have a small base plate, sitting on top of it are 2 pc's of flat bar stock in a "v" 90 degree shape (this will be a weldment) I need the center of the V in the middle of the base plate. I have the v configuration mounted on the base plate but I cannot get the V centered (constrained) on the base plate. How can I do this?
Thanks
Dave

mahir

I agree, it's not always intuitive. Yes, you can offset. The control is in the mate connectors. If you wanted the V to be off-center, you would edit the baseplate's mate connector to move it along it's X/Y axes (Z is always the primary axis for a mate connector). If your V parts have a different shape, then the mate connector would just need to be adjusted accordingly. As mentioned before, mate connectors are just local XYZ coordinate systems that you can place on a part in whatever location/orientation gets you the desired result.

I haven't looked at it myself, but here's a link to an assembly tutorial that touches on mating.
https://learn.onshape.com/courses/fundamentals-onshape-assemblies

emerson_bottero

could you send a picture?

dave_banks

Can you show how to make an angular mate? I think I somehow figured out the previous question. I don't know if I could redo it again though. These constraints aren't very easy to ake.

mahir

OS mates are like a combination of the mates you would find in other CAD. Think of each mate as a way to constrain the degrees of freedom between two local coordinate systems (mate connectors). Offsets can be used to control distance and angle between parts. You can also add limits to these offsets like a limit mate. You get to pick where these mate connectors are located. Case in point, to mate a vertical V to a flat plate in SW, you would need at least 3 mates (line-to-midpoint coincident, plane-to-plane angle, line-to-surface coincident). This is because SW mates only control 1 degree of freedom at a time. With OS, you could just add a single Fastened mate with the proper offsets/angles. The 3 parts below would take at least 6 mates with SW. In OS it's only 2.

dave_banks

Thank you for your response. I am sure Onshape has all the needed mates but they aren't easy to find/use for me.
Is there a tutorial that shows how to use each mate in more detail? If for instance, you wanted to have this V offset from the center, I assume this can be done. If your V parts are square ended (to allow for welding) how would you mate them?

mahir

I agree, it's not always intuitive. Yes, you can offset. The control is in the mate connectors. If you wanted the V to be off-center, you would edit the baseplate's mate connector to move it along it's X/Y axes (Z is always the primary axis for a mate connector). If your V parts have a different shape, then the mate connector would just need to be adjusted accordingly. As mentioned before, mate connectors are just local XYZ coordinate systems that you can place on a part in whatever location/orientation gets you the desired result.

I haven't looked at it myself, but here's a link to an assembly tutorial that touches on mating.
https://learn.onshape.com/courses/fundamentals-onshape-assemblies

máté_rangics

I'm sorry, this is not that it's not intuitive, it's simply horrible. Doesn't matter how many constraints you need to do. This is exactly the problem: it is better to use more constraints, as it is better describing the engineering intent, easier to understand what the designer wanted to do!
OnShape constraining system is horrible, it must be fixed. I'm afraid it will take an eternity due to the shit framework they started years ago.
It is a pain in the ass if you use any other angle than perpendicular, and you'll never find what you really did to somehow miraculously make it work, and it will take all your hair.