Modfying a (sub-)assembly: can I sketch in an assembly tab?

tony_canas

I am a new user, so perhaps my planning is not aligned to the software yet...

I have an assembly of standard, basic parts. I would like to modify that assembly by making an extruded cut or slot at a selected angle that is defined on the whole assembly.  After the cut, the standard parts will be modified and no-longer identical.  This order of action mirrors the way that the parts would be manufactured (make the sub-assembly, modify it at that level).

Is it possible to make a sketch on a face in an assembly, and then to use that sketch to make an extruded cut?  

I suspect that I should have made another parts studio and made up sufficient sketches to make specialised (slotted) parts from my standard parts.  In that case I would need to import sketches and parts from one studio to another...

Can anyone please tell me if my desire to modify a sub-assembly is (a) not possible or (b) not the best way to go about things in OnShape?

Thanks in anticipation...

brucebartlett

You can not sketch or add features in an assembly.

Try deriving the parts into a new part studio and and doing your cut's here, this will also produce new parts while retaining the originals. The great thing is you end up with a very stable solution no moving of parts in an assembly and sketch falling apart.

brucebartlett

You can not sketch or add features in an assembly.

Try deriving the parts into a new part studio and and doing your cut's here, this will also produce new parts while retaining the originals. The great thing is you end up with a very stable solution no moving of parts in an assembly and sketch falling apart.

3dcad

+1 for Bruce suggestion and for positioning derived parts you should look at 'manual' for creating mate connector in part studio and transform by mate connectors. Pretty much same as in assembly but you need to create connectors yourself. This workflow is totally worth learning at current state of Onshape.