I've been trying to come up with a heavy duty rack to store my filament rolls that is built well and doesn't break the bank. Today I found a solution that I love and I wanted to share it here on Thingiverse.
My solution was assembling a rack made of steel electrical handy boxes and 1/2in EMT conduit. It is extremely rugged, works perfect, and is extremely inexpensive to make. You can make a rack in about 10 minutes that holds up to 20 spools with $6.15 in parts. Once made, you can set it on a table, on a shelf, mount it to a wall, the possibilities are endless.
Basic Rack - Total Cost $6.15 - Holds up to 20 Spools
2x #5836134 Handy Boxes $.89ea // Link: https://www.homedepot.com/p/Single-Gang-Drawn-Handy-Box-1-7-8-in-Deep-with-1-2-in-KO-s-8660/100560024
4x #97271 1/2in EMT Connectors $.44ea // Link: https://www.homedepot.com/p/Halex-1-2-in-Electrical-Metallic-Tube-EMT-Set-Screw-Connector-96271/100204006
1x #101543 10' section 1/2in EMT $2.61ea // Link: https://www.homedepot.com/p/1-2-in-EMT-Conduit-101543/100400405
2x2 Rack - Total Cost $29.76 - Holds up to 80 Spools
8x #5836134 Handy Boxes $.89ea // Link: https://www.homedepot.com/p/Single-Gang-Drawn-Handy-Box-1-7-8-in-Deep-with-1-2-in-KO-s-8660/100560024
1x #2122 50pc 1/2in EMT Connectors $9.47ea // Link: https://www.homedepot.com/p/RACO-EMT-1-2-in-Insulated-Set-Screw-Connector-50-Pack-2122/203637583
5x #101543 10' section 1/2in EMT $2.61ea // Link: https://www.homedepot.com/p/1-2-in-EMT-Conduit-101543/100400405
Tools to Assemble:
For anyone not familiar with using conduit with electrical boxes, have a look at this video, it will show you how to put the connectors in the box. https://www.youtube.com/watch?v=i4pH4hUCT7g
Once all the connectors are installed in the boxes, simply cut the 1/2 EMT to length, install it in the connectors, and tighten the screws. For my 2x2 rack pictured above, I assembled 8 of the boxes with connectors. 4 similar to the one shown in the video, and 4 with the 2 inside connectors on the opposite side. I then cut 8 sections at 28in, 4 sections at 9in, and 4 sections at 6in. Then just put it all together. The nice thing with this design is you can use any length you want for the conduit. This makes it easy to make it fit the rack anywhere.
If anyone wants to keep going and make 3+ Tiers, you can use a Handy Box plate with a 1/2 Knockout: https://www.homedepot.com/p/RACO-Single-Gang-Handy-Box-Cover-with-1-2-in-Knockouts-25-Pack-861/202058330 and just keep going up!
The 2 STL files are for anyone that wants to put a blank plate on the handy box. One is a basic plate and the second has a spot where you can store your filament clips so you don't lose them. Each plate will need two #6 screws to attach it to the box.
IMPORTANT! Please keep in mind the box edges are sharp and can cut you. Also, I recommend wiping everything down with alcohol when done to get all the oil off. Definitely don't want oil getting on your filament. Happy Building!