Sturdy Filament Spool Rack - Combined Riser

This is a remix of the combined riser for the popular Sturdy Modular Filament Spool Rack. Instead of putting risers directly beside each other for adjacent racks, we can use a double clip top and bottom with a single riser. This saves on printing time and material. @EllisMakes original double riser was too wide for my rack because I have the interlocking dove-tailed feet on the bottom row of racks and I found the riser was too short. I made the riser taller to match the rest of the rack system and tightened up the clip spacing. I also recommend printing the double clips at a 45° with supports to add strength. I find the tabs on the clips break off if you print them vertically. I've printed some in PLA or PETG and they both work fine. PETG should be stronger. ASSEMBLY NOTE: When assembling them put the rounded nub with the square cut clips towards the inside of the rack. The corner-cut clips go towards the outside. If you reverse this the tabs will break off when you seat them, thou