How to go from Assembly to sketch?

[SherpaDoug]

I have an assembly consisting of a bearing downloaded from a vendor website, and
a shaft I have built up from basic geometry. It all looks nice in 3D.

Next I have to design a bushing to fill the annular gap between these parts. I would
like to view the assembly, select a plane that bisects the assembly, the XY
plane will do fine, and project that geometry as reference figures to a sketch
where I can design the bushing. But I don't see any way to get a sketch from an
assembly.

I can get a sketch from the shaft part file, and another sketch from the bearing
part file. But how do I merge the two sketches to work with some features of each?

 

[wathavy4]

If you uploaded your assembly (as Alibre step) it could have been more elaborated than this..

Is this what you wanted to do?
Or is this similar to what you are facing now?
Actually, with the picture here, there are no bushing needed since pipes are machined to accommodate the bearings.

 

[DavidJ]

Have you tried inserting the bearing into an assembly, then Insert New Part ? - you can now design your new part and can project to sketch form edges/faces of the bearing.

 

[SherpaDoug]

Ah Ha! From the assembly tools "Insert new Part" is the key command I was missing. This is not in any of the tutorials I have gone through. They all show building an assembly from completed parts, not going backwards. I then went down the wrong path, looking to merge sketches from two parts to create a third...
As always, it is obvious in retrospect.

Thanks Guys

 

[HaroldL]

Ah Ha! From the assembly tools "Insert new Part" is the key command I was missing. This is not in any of the tutorials I have gone through. They all show building an assembly from completed parts, not going backwards. I then went down the wrong path, looking to merge sketches from two parts to create a third...
As always, it is obvious in retrospect.

Thanks Guys

Have a look at this post on another thread about Top Down Assemblies. viewtopic.php?f=10&t=10454#p61855

h.