Airtight Filament Canister

I had problems with moisture getting into my filament and causing little pops on the side of my prints. I realized when the problem did not occur with a fresh spool of filament that my filament was absorbing moisture. This Airtight Filament Canister solves the moisture problem and provides convenient storage. It includes a cradle design which allows the filament spool to move freely. The filament is fed through an airtight connection using either 1/4" PTFE or 4mm PTFE tubing. You may use either the 1/4" PTFE connection or the 4mm PTFE connection. The canister is completely airtight except for the small hole in the end of the tubing where the filament exits. The hole is plugged by pushing the end of the tubing into the matching cap. If you would like your canister on a shelf above the printer, you may install the filament port on the side of the canister near the bottom.

The adjustable cradle is better than the previous one piece designs. See Update 5 below. This cradle designs require only four 608 bearings and they print quickly.

The Rubbermaid container is a 21 cup size and can be bought at Amazon.com for $14. https://www.amazon.com/Rubbermaid-LEPUSEMTE469-711717429496-Container-Everyday/dp/B00XJRMW5M

PTFE Ports for 4mm and 0.250" tubing https://www.amazon.com/BIQU-Straight-Pneumatic-Connector-Extruder/dp/B01IB81IHG https://www.amazon.com/PneumaticPlus-PC-1-Connect-Fitting-Straight/dp/B00AXAY47W

The bearings can be bought anywhere including a skate shop and should cost around 75 cents each. The 1/4" PTFE is available from Home Depot. There is no other hardware for this design. 4mm PTFE is available on Amazon.com

I've also included designs for 4mm and 0.250" PTFE tubing supports.

Update 2-16-2017: I have added an alternate design for the PTFE port to support 4 mm tubing. The new design uses a cap and a clip rather than an integrate cap port. It uses the same spool cradles. I did this redesign so that I could better support CoreXY and HyperCube printers with a port mounted low on the container. You will need a 10mm PTFE connector and will need to drill a hole to mount the connector. See the photo.

Update1: I have been using my new canister quite a bit this week and noticed that it feeds better if you face the canister and PTFE so it follows the natural curve of the filament coming off of the spool. (Makes sense doesn't it :)

Update2: I printed another one of these setups and I am keeping my favorite filaments in these canisters. It is much easier to hook them to my printer and it is easier to seal them off rather than zip lock bags which is how I store my other spools of filament. This canister has eliminated any problems I was having with moisture getting into my filament.

Update 3: I added a filament guide that mounts on the printer and receives the 0.25" PTFE guiding it to the middle of the top of the printer. This makes it easy to connect and to swap out canisters. You clip the filament, unplug the tubing and plug in another canister.

Update 4: The original clear 21 cup hard plastic Rubbermaid container has gone way up in price ($70!!!!). There is still a soft plastic 21 cup version available for $11 each. I have supplied the link for that container. The new container has a one piece lid and is slightly opaque.

Print Settings

Printer Brand:

RepRap

Printer:

Prusa i3

Rafts:

No

Supports:

No

Resolution:

0.1 or 0.2mm

Infill:

40%

Notes:

PLA

Extruder 200C

Bed 60C on Kapton

Drill a 3/8" hole if you are using the 10mm PTFE connector and use two layers of Teflon tape to seal the connection. The fitting self threads into the soft plastic. You could probably leave off the Teflon tape and it would also seal fine.

Post-Printing

Cleanup and Setup

After printing the spool cradle, you may have to clean the holes with an 8 mm drill or a file.

The pins have a very small expansion on the end to retain them. If they can't be pushed in, you may have to sand them a small amount. My pins click into place firmly.

The 21 cup Rubbermaid Container is part number 1840750. You will need to drill a 1/4" hole to one end of the cap and then use a step drill as shown to open it to 1/2". The step drill gives a clean not ragged hole. Glue both the filament port and the retaining bushing to the canister cap using Super Glue (for PLA). Clamp it in a vise or other method to create an airtight glue joint. Push 14-16" of 1/4" PTFE tubing into the open port. Set the cradle in the bottom of the canister and feed the filament from under the spool up through the port, tubing, and to your printer. When you're not using the filament, remove it from the printer and plug the open end of the feed tube into the sealed secondary port. You can also throw a couple bags of desiccant into the bottom of the canister. Your filament will stay nice and dry. You'll be surprised how many print problems are solved by eliminating moisture in the filament.

Category: 3D Printer Accessories