Auto adjust the side of a device shape

[logicr]

Hello All,

I am new to Visio, and iam creating visio file for our network devices and servers.
First i was having issue to Connect the device to the rack (Connecting ) i resolved it by using the below link.

Now i can take jpg image of a device(because no stencils available) and succeed to insert them to the Rack.
Buy now the problem is... If i select all, i mean rack and all devices and increase the size,, then the original stencils got from the manufacture are getting their height increased but not the one which i created.

Example. If i increase the size of the rack, the device i created (2 U) is fixed to rack which is good (fit to the width) but  the height which was 2U has become less then 1 U.  i have to go to each and every device and increase the height each time i modify the rack.

So my question : how can i make the devices which i created to auto adjust their height. Like the original shape provided by the manufacture.

Please help me friend. as i am dying with this problem.

Thanks for your help in advance.