Clamps for DIY Sterilite bin filament dryer

Want to dry a ton of filament on a budget with little to no hands-on time? Follow along to build your own DIY filament dry box. This thing is a clamp that secures the lid of a Sterilite bin (32 quarts) with a gasket to reduce the amount of moisture that can enter the bin. When I add metal canisters containing activated alumina desiccant and a humidity sensor to a bin containing filament and then clamp the lid closed, the humidity decreases until it levels off somewhere ~1-2%.

Print Settings

Printer Brand:

Creality

Printer:

Ender-3 V3 SE

Rafts:

No

Supports:

No

Resolution:

0.4mm nozzle

Infill:

16% (gyroid)

Filament: Overture PETG Starry Blue

Notes:

Model notes:

• Clamp is 0.51mm tall, allowing for exactly 17 0.3mm layers

Additional slicer settings:

• 5 top and 5 bottom layers
• Temperatures: 235C nozzle, 75C build plate (textured PEI)
• Print speed: 60mm/s infill, 50mm/s walls, 30mm/s initial layer
• Retract at layer change (1.5mm at 45 mm/s)
• No print cooling
• Skirt only (no bed adhesion needed)

Materials needed to complete

• Sterilite storage bin with gasket:

  1. I used a 32 quart bin that can be purchased from Walmart, Target, and likely other locations as well. Best price seen: $10 USD
  2. The 54 quart may be able to be used as well since the built-in latches are in the same locations as the 32 quart bin. NOTE: I have not tested these clamps on other bin sizes.

• Desiccant:

  1. 2-pack Silica gel desiccant container (Amazon, best value for money among similar options). Best price seen: $16 USD
     • Pros: self-contained, single purchase, reusable (by heating in oven), color-changing to indicate when reheating is needed.
     • Cons: Lower total of moisture able to be absorbed
  2. 1-pack Activated alumina desiccant container (pre-built, Amazon). Best price seen: $15 USD
  3. Activated alumina desiccant container (DIY, makes 10 canisters)
     • Metal canisters Amazon, pack of 12. Best price seen: $19 USD
       • I drilled extra holes in my canisters to allow better airflow and moisture absorption
     • Activated alumina Amazon, 2 lbs / 1 quart -- this is enough to fill ~10 of the above canisters. Best price seen: $18 USD

• Humidity sensor - Amazon - $7 USD

  • The lowest value I've seen it display is 10% humidity
  • Having two is useful to compare ambient vs in-box humidity

• Clamps

  • Print 4 clamps (this thing) using PETG.

Tips and tricks

1. I drilled extra holes in the sides and bottom of my metal canisters using a ~1/8" / ~3mm drill bit. If you do, be sure to file down any sharp edges that remain.
2. Use a funnel to fill the metal canisters with activated alumina. Don't over-fill them.
3. Once the canisters have been filled and the mesh lids are on, I recommend weighing each canister and writing the initial weight down on a piece of paper. Kitchen food scales are a good option here (use grams).
4. Heat the canisters in the oven at ~425F / ~220 C for 30-60 minutes, and then re-weigh each canister. If your scale doesn't have high resolution, consider weighing all of the canisters at once. You'll notice a decrease in weight due to water evaporating out of the alumina beads.
5. Heat for an additional 30-60 minutes and re-weigh each or all of the canisters. Repeat until the canisters are not losing weight at a meaningful rate. In my experience, 30-60 minutes is sufficient.
6. Allow the canisters to cool in the oven. This will reduce the amount of moisture they absorb from ambient air.
7. One cool, canisters can be placed inside spools of filament. Place the filament + desiccant canisters in the Sterilite box, add one humidity sensor, and then close the built-in latches.
8. Attach the 3D printed clamps to the Sterilite -- two on each side. Place in the handle area of the Sterilite bin, as far apart as possible (~4 inches / 100 mm apart).

Final notes

I haven't compared how my DIY filament dryer box compares with commercially available filament dryers, nor have I experimented with adding fans to the box or heating the filament prior to placing it in the box with the desiccant. It's possible some filament requires gentle heat for all the absorbed water to be released.

However, in my hands, the activated alumina can pull moisture out of the filaments I have (PLA, PETG, and TPU). How do I know?

• Adding 1x desiccant canister and 1x humidity sensor to Ziploc bag --> substantial decrease in humidity within 30 minutes.
• Adding 6x desiccant canister and 1x humidity sensor to clamped Sterilite bin --> substantial decrease in humidity within 30 minutes.
• • Adding 8 rolls of filament + 6x desiccant canisters + 1x humidity sensor to unclamped Sterilite bin --> Humidity stayed at ~30% while ambient humidity was ~50%.
• Adding 8 rolls of filament + 6x desiccant canisters + 1x humidity sensor to clamped Sterilite bin --> Humidity stayed >20% for ~4-5 days before dropping slowly to 10% and settling there (lower limit of sensor).
• Quality of prints using moisture-sensitive filaments (PETG and TPU) has substantially improved following time in a <10% humidity dry box (no heating or fans needed).