Simple and quick printing solution for holding multiple spools in a drybox. 

Hardware required:

• (2) 5/16th all-thread rods
  • 8mm may work if holes in legs are slightly enlarged
• (8) 5/16th nuts
• (16) 608 bearings
  • This is for a 4 spool version, you'll need 4 per spool
  • These don't have to be expensive, but will need to be cleaned & oiled if they have sticky residue on them

Can be expanded or shrunk to utilize the box/space you have. All-thread should be cut to fit then you can print an appropriate number of rollers & spacers to fit the cut all-thread.

All parts should print in the provided orientation without any supports or special care.

Printing:

• You'll need 2 of the legs
  • More can be added in the middle if you're building an extremely long holder and are worried about sag
• You'll need 2 of the rollers for each of the spools you wish to hold
• You'll need 2 fewer spacers than you have rollers

Assembly:

• Press bearings into each end of the rollers, one should be flush with the end, the other will be inset roughly the thickness of a 5/16" nut.
  • These are a fairly tight fit, it may help to press them in when the rollers are still warm. If you still have problems you might try scaling the rollers up very slightly in the x and y dimensions to provide a looser fit
• Thread a nut onto the all-thread about ¾" down
• Insert the rod into the leg
• Thread a second nut onto the all-thread roughly flush with the end
• Slide the leg back towards the 2nd nut
• Tighten the 1st nut back against the leg until secure
• Repeat for the 2nd piece of all-thread
• Slide a roller with the flush bearing side towards the leg on each of the rods
• Slide a spacer on each of the rods
• Repeat the above 2 steps for the number of rollers you'll be using, leaving out the spacers on the final round
• Thread a nut onto each of the rods loosely tightening it down against the final roller bearing
• Slide the 2nd leg onto the rods pressing it against the nuts
• Thread a final nut onto each of the rods and tighten it against the leg

I used this along with https://www.printables.com/model/612717-pc4-bulkheadpassthrough and https://www.printables.com/model/612693-lack-multi-pc4-filament-guide to create a mostly sealed dry box to print enclosure so that I can leave a number of spools on the printer and quickly switch between them without opening the box.