cavity question

I need to make a cavity in a component, so within the assembly, I used the
cavity feature on BlockA, referencing a casting that is in the top level
assembly. In another configuration, I need to move BlockA with respect to
the referenced casting, but I want the cavity cut to stay unchanged relative
to the origin of BlockA. Is there an external reference that needs to be
broken?
I looked at the external references in BlockA, and the only option is to
break All external references, which would appear to include sketch entities
on other features, on which I want to keep the external refs.
I am a newbie on the cavity feature, and I have probably missed something
simple.
Thanks, Bill

 

"cavity feature on BlockA, referencing a casting"
"I need to move BlockA with respect to the referenced casting"
"I want the cavity cut to stay unchanged relative to the origin of
BlockA"

Seems to be inconsistent statements, quoted above, so I am not sure of
what is desired.

Bo

 

Try, insert-component pattern-, with block A selected. Then
supress/hide the original block A.

 

Bill
Try creating configurations of Block A, one that has X dimension to the
origin and one that has x-1 dimension to the origin. This in essence moves
the block around relative to the origin. In your "Cavity" assembly create 2
configurations, One using the X dimension Block A configuration and one
using the X-1 block A configuration. You can change the configuration of
Block A by a RMB under component properties.
Hopefully this is what you were looking for.

Mike

 

maybe what I actually need to do is subtract the casting from BlockA, so
that the "cavity" doesn't depend on the relative position of the casting
with respect to BlockA. I found some help file stuff on combine/subtract.
I'll see if I can decipher it.
Bill

 

I figured out how to do it.
Had to make an assembly out of (only) BlockA and the casting, and then save
it as a part file.
Now both solid bodies are in this part file (this is what I wasn't picking
up on before).
The combine/subtract feature now seems pretty simple and does what I need.
I am still wondering if the altered BlockA has a "live" external reference
to the original casting file used
for the subtract. I'll save that for the morning.
This is probably simple stuff for many, but I just never needed it before.

bill

 

Bill,

You might consider doing this in part mode instead of an assembly. In
in-context assemblies, you can't control the point in history where
things are done without some crazy wrangling.

Use Insert Part to put the part you want to use to make the cavity into
the part with block A. After the cavity (called Combine, Subtract in
part mode), use a Move Bodies feature, so the cavity is parametric and
the move is parametric and history based.

If you break or lock references and god forbid something changes,
you'll be going back through and doing a lot of work over again.
Another thing you could do would be to have multiple instances of the
part you want to move in the moved assembly config.

good luck,

matt