Radial attachment of part on cylinder

felix_meyer213

I have this rocket and a fin. How do I attach the fin radially in the assembly? And how can I space 4 of them evenly around the rocket? I've tried using the fixed mate tool but it does not work.
 

steve_shubin

@felix_meyer213

Cylindrical Mate with Limits, provided the outside face of the rocket, and the part of the fin that touches the rocket, both have the same radius

https://cad.onshape.com/documents/890aeb7dcf81d91801cc91c5/w/889552ad99e850010f17c77a/e/46b878188c8cb3e790fbffd9

eric_pesty

@steve_shubin
That's just a fasten mate with a Z offset (rather than cylindrical with limits...)

@felix_meyer213
There is no "fix" mate. Fix just makes a part immovable but not relative to any other part, best practice is to "fix" one part in you assembly and then mate the other ones from there.
I would suggest doing the training on assemblies, it goes over the different types of mate: https://learn.onshape.com/learn/course/fundamentals-onshape-assemblies/creating-an-assembly/starting-an-assembly

steve_shubin

@eric_pesty

They are similar. But not quite the same

During your design stage, the cylindrical mate is easier for you to move around and look at, and then move it a little bit more, and look at it. So if you’re the sort that likes to design that way — as might be the case if you were designing a toy rocket, then cylindrical is what you might want to use

You could also be designing some type of a consumer product that has a cylindrical aspect to it and you were going to be attaching something to the cylinders surface in a similar manner, and this item was something that you were going to be moving a lot until you dialed in the exact location. Cylindrical could come in handy in this case also

But it was great that you showed how there are a few ways to go about this particular situation