Filament Dry Box Port, 3mm

thingiverse

I needed a dry box for my active filament reel because long prints with PLA can absorb moisture from the air, causing print problems. Most designs I found were for 1.75mm printers, but I have a 3mm printer. It needs to stay relatively dry, so I chose a container with a good airtight seal. Then, I designed a port that allows the PTFE tube from my printer to pass through while maintaining a tight seal. Parts: The following measurements are from the packaging. I wish Americans would switch to the metric system; so sorry about the mixed measurement systems. Parts: (1) Snapware 40 cup (9.5L) container (https://www.amazon.com/Snapware-Airtight-Rectangular-Storage-Container/dp/B007V4IWIU/) (3) O-rings, 11/32" O.D. x 7/32" I.D. x 1/16" (2) Neoprene washers 5/32" for the mounting screws (1) Neoprene washer 7/16" for the main PTFE tube hole (2) Two screws and nuts that fit (2) Two of the printed parts (they are symmetrical) Useful Tools: Hole Reamer Tool (https://www.amazon.com/Hobbypark-0-14mm-Puncher-Reamer-Drills/dp/B01EIH573K) Instructions: Print two of the parts using a fine setting; one for the outside and one for the inside of the container. This provides good surfaces for the inside-mounted O-rings. Insert two O-rings into one printed port, which will be the inner port. There are two races for O-rings in the design on the inside; I used a dull dental pick to guide the innermost one first and then worked on the outermost one. Insert one O-ring into the other port, which will be the outer port. This is meant to provide stability rather than a seal. Cut three holes aligned with the holes on the printed port in the side of your box. While I placed this near the center height-wise, it would have been better at about 1/3 from the bottom. I used a hole reamer tool that can be pressed and rotated to create a hole of any size up to its maximum taper. Use the inner hole size of the neoprene washers as a guide for the size of the holes to cut. First, loosely assemble all the parts with the neoprene washers on the inside of the box and the port with two O-rings also on the inside. I used the PTFE tube already inserted to make sure everything lined up. Align the ports so one points upward and the other downward according to your use. Then, slowly tighten the screws while making sure the neoprene washers are aligned well to provide a seal. Once snug, tighten a little more to slightly compress the washers without causing any stress on other parts. Hint: Rotating the PTFE tube while inserting it into the port will allow it to go in more easily.