How to change model lengths via familytable with keeping their clearance?

[Yu_707]

Hi there,

I'm now trying to change part model's lengths by using the familytable feature. The part should have a clearance against the other part, however, I cannot set the clearance on the familytable. Could you have any idea to recognize the gap between part models and set it to the familytable?

[tbraxton]

From your description you are attempting to do several things.

1) Measure the gap between part A and Part B  (this implies you are in assembly mode)

2) Use the measure from step 1 to modify the same gap distance

You can create an analysis measure feature in the assembly to determine the initial value of the gap in step 1. If you can calculate the gap without doing it in the assembly then that may simplify things. Is it possible to predict the gap using part dimensions. You could also use an external copy geom to get the gap measure.

This value is then available for use in relations which can be written to modify the dimension(s) of part(s) A &/OR B to modify the gap value

I am not sure that a family table should be your first choice to do this. If can elaborate on the design intent that may get you a better solution to your issue.

[remy]

You try to drive the overall size of a model with a family table and have a Creo compute a resulting gap between parts downstream.

This is a two stage process. 

I guess you figured how to drive the size (the length). 

You need to find a second mechanism that would trigger after the instance is loaded. 
Measure Feature is a possibility another is Pro/Program.