Mounted in 80 quart box 8 rolls fit nice. The Sterilite 80 quart box will require a firm base I used 2by4's. 1st screwing 4 pads to the 2by4's and then screwing the 2by4s to the 80 quart box and using screws from the bottom of box. Or could use ¾ plywood in bottom of box would work nice. What ever works for you but when the rolls are added there is just to much weight and you will need a firm base.

For guides used Drybox filament guide using PTFE tube. Just use a step drill and drill holes in centered locations to each pad. They work nice print a plate of them you will use them.

Spool Pad

Pad is 3.250 by 5.700 by .500 thick

Holes are made for 3mm screws.

Used 25 % infill

Prints needed for each Spool

4 Mini-base-spoolholder.stl

1 Spool Pad

1 Fitting

1 Nut

Metal parts needed

4 Bearings 8mm x 22mm x 7mm Amazon.com: Tonmp 200 PCS 608-ZZ Ball Bearing - Double Metal Sealed Shielded Miniature Deep Groove Bearings for Furniture Wheel,Skateboards, Inline Skates, Scooters, Roller Blade Skates (8mm x 22mm x 7mm) : Sports & Outdoors

8 Screws M3 - 14mm M3-0.5 x 14mm Button Head Socket Cap Screws, Stainless Steel 304, Full Thread, Allen Socket Drive, Heavy Duty Machine Hexagon Screw Drive 100 PCS: Amazon.com: Industrial & Scientific

4 Nuts M3 100Pcs M3 x 0.5mm 304 Stainless Steel Self-Lock Nylon Inserted Hex Lock Nuts, Self Clinching Nuts: Amazon.com: Industrial & Scientific

4 Screws M3 - 50mm M3-0.5 x 50mm Button Head Socket Cap Screws, Stainless Steel 304, Full Thread, Allen Socket Drive, Heavy Duty Machine Hexagon Screw Drive 50 PCS: Amazon.com: Industrial & Scientific

Screws to hold 2by4's or plywood in boxes can use wood screws are what ever ya need to keep it in location. I used 8 Screws M3 -50mm they work fine in wood just drill hole .093 and put like 8 around bottom to hold wood in place. Use picture bottom of box for reference.

Dry Box used

Amazon.com - Sterilite 80 Quart Clear Plastic Stackable Storage Container Box Bin with Air Tight Gasket Seal Latching Lid Long Term Organizing Solution, 12 Pack

Notes

The whole goal of this prject is to use spool boxes and then mount them above the printer with the colors ya want to print all mounted above the printer. Will take some time.

Parts are snug so might require light tapping to fit or good cleaning of support material.

Going to be making Spool Pads for 2kg Prusament spools in future will be the same just wider pad and going to mount them in box with ¾ plywood for base. This project has been Big one and found some help full free cad software Tinkercad | 3D Design is free and simple to use great for projects just like this.

Also this project of 32 Spool pads and rollers would not of been easy without Automation solution for 3D printing | JobOx – jobox shop in my Onion very handy addition to MY Prusa Prusa i3 MK3S+ Made Print file to print 2 spool pads and then repeated 16 times it loads the print plates and takes them off saving TONS of time overnight and during the day. BUT have found you need very flat base for printer and the JOBOX that has been the only thing other wise has worked Super. Just turn on crash detection and if plate fails to load it just stops. Also have raised the bed temps by 10 deg for 1st layer and other layers. Is that why lost a few prints IDK but this printer was on POINT and then made the upgrade so up the bed temps a little and give that a try. Only using 3 plates right now and that's enuff for cause you just clean plate and load it back in rack.