1 Nov 2020

DIY 3D printing filament dryer

DIY Filament Dryer

How I built a DIY filament dryer from an inexpensive food dehydrator for my Creality Ender 3 V2 3D printer. This houses a standard 1kg spool of filament, allows printing directly from the dryer, and improves print quality and consistency.

Why dry filament?

I live in a sub-tropical climate which means typically high humidity for much of the year. Many filaments are prone to absorbing moisture from the air which causes issues with print quality and consistency. When printing with PLA, I had issues with stringing where the filament wouldn’t break cleanly but instead string across the print like spider webs.

Comparison showing dried PLA prints with much less stringing
Comparison print using undried PLA filament (left) vs dried (right).
The dried filament shows much less stringing and a cleaner finish.

I also wanted to position the filament spool next to the printer, not on top as is typical. This is more convenient for changing filament but can also help to reduce ghosting artefacts in the prints.

Ghosting is slight ripples in the horizontal surface of a print, caused by vibrations ‘reverberating’ or ‘ringing’ in the printer frame. This is exacerbated by the weight of the filament spool when mounted on top of the frame.

Build instructions

What you’ll need

  • A food dehydrator – I purchased a Devanti 5 try food dehydrator (model: FD-BT5-1142-BK) for $55 on eBay.
  • A PTFE bowden tube and PC4-M10 fitting – I purchased this for $15 on eBay.
  • Tools for cutting the plastic trays – Strong side-cutters, assortment of files, or a Dremel.
  • A 3D printed adaptor to connect the PTFE tube neatly to the side of the deydrator. I have made this part available on Thingiverse.

Step-by-step instructions

PC4-M10 Adaptor

Step 1 – Print the adaptor

Download the adaptor from Thingiverse and start that printing. I used 0.12mm layer height, 50% infill, and no supports or rafts.

Step 2 – Modify the food dehydrator trays

The food dehydrator will come with 5 trays and a lid. We only need 3 trays for a standard 1kg filament spool, so put 2 trays aside.

1 of the 3 trays will be used as the base to hold the spool. This can be place on the dehydrator base, no modification necessary. The trays have a raised circle in the middle that conveniently holds the spool and allows it to turn easily.

Filament Dryer Tray - Unmodified

the 2 remaining trays will need the centre mesh cut out of them. Use some strong side-cutters or a Dremel to cut the mesh out so you are left with just the tray’s outer rings.

Filament Dryer Tray - Centre Cut-Out

Step 3 – Fit the PC4-M10 fitting to the adaptor

The PC4-M10 fitting is obviously M10 (metric 10mm diameter). The 3D printed adaptor has a 9.5mm diameter hole for the fitting to screw in securely. You may need a wrench/spanner. The PTFE tube can then be inserted into the fitting – push it through so that it’s flush with the other side.

Step 4 – Mount the adaptor to the dryer

Take one of the tray rings and file a 25x13mm notch on the side from the top, as shown…

Filament Dryer Tray - Notched For Adaptor

Step 5 – Insert filament and connect to 3D printer

The adaptor can now be slid in to the notch from the top…

The dehydrator trays should be stacked as follows (top to bottom):

  • Lid
  • Tray ring – mesh cut-out
  • Tray ring – notched with this 3D printed adaptor installed
  • Tray ring – unmodified (filament spool will sit on this)
  • Food dehydrator base

Connect the PTFE bowden tube to your printer’s extruder. Here’s a view from the top (lid removed from dryer for this photo).

Filament Dryer - Top View

Ready to print!

Ensure that the filament spool can turn freely and isn’t hitting anything.

Set the dehydrator to it’s lowest temperature setting, and turn it on. After a few minutes, turn it to the middle setting. I measured this at 45~50°C which has given me good results with PLA – you may wish to check this with a thermometer on your setup or research other temperatures if you’re using different types of filament.

With that all put together, it’s ready to go! 🙂

About the Author:

Hardware and software engineer with experience in product development and building automation. Director at Cabot Technologies and Product Manager at NEX Data Management Systems.

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