I needed to attach 2 Ikea VESKEN Shelf units together to use as spool storage, this allowed me to do so

The VESKEN will hold both boxes and/or spools and two unites will hold 42 spools or boxes

Please Note: going up to the 7 levels was too heavy for the wheels when fully loaded, if you need to move them around freely use this suggestions:

• up to 5 levels fully loaded in every level
• up to 6-7 levels partially loaded for at least 3 levels

Printing:

• Support is required
• I was able to fit 2 count in K1 Max
• I was able to fit 1 in Bambu X1
• I didn't try to print the 2 sides (I've cut it with PrusaSlicer)

Also, you might be interested in a related design. The IKEA VESKEN Wall Rail,Guide & Support