A very simple, expandable, filament spool rack. Just keep adding more bases. Comprises 2 parts: a base and a joiner. Note - not designed to allow spools to dispense filament. It's just for convenient storage. To get started, print 2 bases and two joiners then clip them together. I found using some adjustable pliers worked really well. Just make sure you clean up any brim material around dovetails. For each additional spool, print one base and two joiners - easy If the spacing doesn't suit your spools just remix the joiner to suit.