Master modelling is the technique employed by many designers that work with external customer data. It allows the user to import a part into another part document. With an inserted part, new geometry can then be referenced to the inserted part ensuring adequate fit and clearances are maintained. Take for example a simple consumer electrical product like an electric shaver- the main body may be used as the inserted master part to allow other items to be designed- such as button details, or the razor mount. Using the main body as a reference will ensure the shape and fit is correct.
To insert a part, simply use the Insert > Part menu string:
When inserting, you will be asked what data you want to bring along- choose these from the check boxes and determine whether you want a link established back to the master.
If you have received a model with an inserted part and are worried that you don't see the latest information, investigate the symbol attached to the part in the Feature Manager Tree- it will show one of four symbols:
-> External reference intact and up to date- the master model is open in the background.
->? The reference is out of context and this may be because the master model is not open or cannot be found.
->* The reference has been locked to prevent changes from propagating- locked references can be unlocked.
->x The reference has been broken preventing changes- and this is irreversible.
If you wish to interrogate further you can right click the inserted part and choose "List External Refs.." this reveals a dialogue showing you the expected location and name of the inserted part, and details about any links.
Master modelling is an example of multi-body modelling, as it is employed through the part mode rather than assemblies. The new part file has a reference back to the inserted master model, so in the event of any changes, these will propagate through. The question we sometimes get asked though is- what if we want to completely substitute the master part for a brand new one?
The answer isn't obvious, and the way to actually do this is to change the reference prior to opening the file. When you use the File > Open dialogue, select the file and click the References button. This shows you the master model's expected location, and in here you can double click the file to substitute. This is actually the same way that you can replace part references in the assembly and drawing views.
This will then replace the part, but you may now find that any downstream features develop warnings that need to be aligned to the newly replaced inserted part.
By Adam Hartles