Real-size blocks

I made 2 MDF blocks in scale 1:1 (this time square's dimensions: 6x6 cm). Holes diameter: 2 cm. Rods: 19mm. It's working but 1mm difference between hole and rod actually makes a difference, it's too loose, so not very stable as a result.

To make blocks more stable I drilled smaller holes (4.5mm) in thick rods and stuck thinner ones perpendicularly - like on this draft:

This is how it looks like on real-life model:

It works surprisingly well, everthing is more stable, but now I'm dealing with only 2 block and 2 rods. It would be way more tricky with more elements, because holes have to be drilled realyy accurately and on the same angle (not easy). 

Bad news - assembling and disassembing my thing can take ages with so many elements.