Design features

• Affordable (~$25 for 4 units + printing time)
• Fully sealed
• Adjustable width to accommodate different containers and spools
• Steal Pins instead of more expensive and narrower Ball Bearings
• Option to not modify the original food container in any way (no drilling etc.)

Additional Materials

• Pneumatic connector, PC4-M6 or PC4-M10 (for 1.75mm filament)
• Bowden tube, 4mmOD for 1.75mm filament
• For food containers, the keyword is “4L sealed container*”
• Steel pins, D6*20mm (optional, but recommended)

* I molded this part based on the most common & cheapest 4L container on amazon, but any container with a circular opening will likely fit as they all use the same ODM mould. I'm not affiliated with this particular product or brand in any way.

Compatible Spool Dimensions (mostly 1kg or fewer spools)

• Width: 48~78mm, depending on your choice of the spacer.
• Diameter: 185mm-205mm, depending on your food container size.

Model Variants Explained

Two Cap versions:

• “ConnectorCap - Replacing" will replace the container's original cap and goes into the spout. Choose this if you don't want to irreversibly modify the container.
• “ConnectorCap - Integrated” goes to the inside of the container's original cap, and you will need to drill a hole for the pneumatic connector to go through the original cap lid. Choose this for better convenience opening and closing the cap.

Two Cap Screw Sizes:

• M10 threaded pneumatic connector allows the PTFE tube to fully go through, therefore reducing the drag of filament catching the connector, thus preferred. If you only have M6 connector in hands then use the M6 variant.
• If you are having trouble printing the threads (this may occur on larger nozzles or calibration issues), please print the no-thread version and directly screw in, or drill the hole bigger and use glue.

Width Spacers:

• Depending on your container and the spool width, choose a properly sized spacer. Notice that the number on the spacers indicates the total width of the rack, not the spacer itself, so you should match this value with the internal width of your food container. Either measure or print several variants and test-fit them.
• Typically, as long as the box can fit the rack, there is no issue of putting a narrower spool onto a wider rack.

Instructions

1. Screw the pneumatic connector into the part SealedConnectorCap
2. Press SealedConnectorCap into the opening of your food container
3. Clip the WidthSpacer of your choice into the RollerBase. If your printer is calibrated well they should be a snug fit with no glue needed.
4. Glue the steel pins onto the RollerBase.
5. Put the base into the container, and put the spool on it.
6. Plug the Bowden tube into the pneumatic connector (the other side should be your printer).
7. Route the filament through the pneumatic connector through the Bowden tube.
8. When not used, you can clip the filament to the cap's clip, and plug the connector to seal it.

Others

Please let me know if there is an issue, or if there is a common container/spool you would like me to accommodate by modifying the model.