The last sample container you'll ever need! Or a design for one at least... This is a fully parametric design I made in Fusion 360 that allows anyone to quickly generate a sample box of whatever size they want with whatever size holes for the sample containers. I'll quickly walk you though how you go about using the parametric features in Fusion: 
 

In Fusion Navigate to Modify → Change Parameters.

Here you'll see this window: 

I've put some handy descriptions after each parameter explaining what they do, but have a play around and see what kinds of shapes you can generate. To change a parameter just click on the value or expression box for the one you want to change and type whatever you want. 

The lid and lower of the box will automatically re-scale to your changes. The lid is held on with two rubber bands and the channels these sit in will also be auto-generated, but you can change this too if you want in the parameters. In my photos about I have some very simple borosilicate glass vials in the container but we've printed versions of this that take centrifuge vials, Teflon capped GC vials, pipette tips of all kinds of shapes and sizes, large lag bolts from a vacuum chamber, and loads of other stuff. 

Please leave a comment if you want a custom size: 

If you don't have access to fusion but have a specific sample size you want, leave me a comment here and I'll happily type your values into the program and provide the 3mf/STL files for you. I've intentionally not included STL files in my upload because the point is you can just generate your own, but I understand some people might not want that so please reach out if you need help.