I recently received a support call where a customer wanted to make a change to a part in his assembly. The part he wanted to change was built in-context. This means that the part was attached to the geometry of another part in the assembly with external references. What the customer wanted is when he changed the size or shape of one part in the assembly, the part that was attached to it would change automatically to match the new size or shape.
When the Gold Base is changed the jaw plate should also update to match the Gold Base. Notice how we change the dimension of the Gold Base from 90 to 70, the Jaw Plate also updates.
This happens automatically because of the external references. These are created with In-Place mates which are created automatically for in-context parts to prevent movement of the parts.
This is how this is supposed to work. However, the customer was making a change and his part was not updating and he could not figure out why. Take a look at the screen shot below to see an example of what was happening.
Notice how the Gold Base is now smaller than the Jaw Plate. They both should update together. There are a couple of explanations of why this is happening if you have in-context parts. The external references of the part are either broken or locked. Let's take a look to see if we can fix it. By right mouse clicking on the Jaw in the Feature Tree, we can look at the List of External References of that part.
Here we can see that the external references of this part have been locked. Luckily, the references have been locked and not broken. If they are locked, you can unlock them. If they are broken, they can NOT be unbroken. Just select unlock and now the part can be updated as expected.
Now the part can update the references.
A couple of key things to remember when working with external references. If you want to stop the updates from happening, lock the references. If you break the references from the List External References command, they cannot be unbroken.