16mm pipe frame for stacking / storage filament carton boxes

I had a lot of carton boxes from my filament supplies and I want to use this as storage vor parts. To create a inexpensive frame I found the 16mm pipes used commonly for electric installations.

A example frame is for my filament boxes with size (W x D x H) (219 x 205 x 77)
3 pcs 16mm pipe length=100 mm
10 pcs 16mm pipe length=195 mm
20 pcs 16mm pipe length 140mm

To have the center of weight better in the center I recommend to use all beams with same length as example 30pcs 16mm pipe wit