123D link : http://www.123dapp.com/AssetManager/Publisher?stgAction=getProduct&intProductId=597956
“Submitted by DIN 2012, Université de Montréal, industrial design program, for the Instructables Sponsorship Program”
Step 1: 3D print
The STL Files are below.
Dumbbell moyen (part 1 and 2) is for 83.75 mm diameter cans.
Dumbbell small is for 73.25 mm diameter cans
*Note that not all printers print equally and that different materials wont shrink the same way. If you use a different printer or a different type of plastic, you might have to adjust some settings to get a perfect fit.
If you are having difficulty getting a good resolution with your UP!, I suggest you also build this box as showen in this instructables :