Lightweight Drybox

This drybox was inspired by the dessicase by Nyles, but i designed everything from scratch, since i don't like the method to mount the spool he uses - also it was a nice learning experience designing the bottom corners.
This thing is designed for ⌀20cm spools with a width of up to 75mm - ⌀22cm might work too, though the spool might have contact with the bag.

Update: I've added a shorter version of the roller with an axle distance of 10cm instead of 12cm, so it will work with smaller spools as well (tested with ⌀15cm)

BOM:
- 4x 608 ball bearings
- 1x M6 pneumatic connector
- 6x M3x16 screws + wingnuts
- 2m ⌀8mm aluminumtube (or wooden stick, carbontube ...)
X 5x 80mm; Y 2x 200mm; Z 4x 230mm; 2x 100mm
- 8l Ziplock bag https://www.amazon.de/gp/product/B00GHN9AVE/ (33cm x 37+3cm)

Tools: 3mm and 8mm drillbit, M6 tap (i've designed the parts without any tolerances - after carefully drilling out the holes everything has a nice friction fit)

For the seal i've used 3mm t