When printing with materials such as Nylon, PETG, or Ninjaflex, one can find that some of these filaments can be hygroscopic (absorbs water.. in this case, from the atmosphere). Once water is absorbed into filament, the print quality and ease of printing can plummet and make for some pretty miserable prints.

One way to dry filament is to put it in an oven. This is great if you want to spend the money on a food dehydrator or your spouse doesn't mind you putting plastic into your nice new kitchen oven. However, one other way it to use a chamber and a light bulb. This method works well but different materials can require different temperatures due to glass transition temperature (the point where plastic begins to soften).

By using arduino, we can build a closed loop control drying box that works similar to your oven.

Set your max temperature allowed, your amount of temperature tolerance, the number of hours you'd like to dry and you're good to go. The controller heats the chamber up to your max set temp, turns the light off until the chamber hits the Max temp - tolerance then turns the light back on again to continue cycling.

After the specified number of hours, the controller switches to "Humidity Hold mode". The user inputs a maximum percentage humidity to hold in the chamber and the controller only turns the light on long enough to keep the humidity below that percentage. It's a nice energy saver mode if you're not going to get to your newly-dried filament right away and bag it up.

Through our testing, I've been able to dry nylon that was submerged in water for a few days and get perfect prints again.

You can see the results of the dryer in my 3 part Youtube series here:
https://www.youtube.com/watch?v=nOc5qVhb3rc Part 1
https://www.youtube.com/watch?v=NQ3DC4GpA3w Part 2
https://www.youtube.com/watch?v=ehsgazhJ17U Part 3

The instructions will be put on instructables soon, but for now here is a link to the word document that takes you step by step through the entire assembly process; pictures included.

UPDATED 6/5/18 - Updated code to fix small bug.

https://www.dropbox.com/s/kurxwfxka75e9hu/DIY%20Closed%20Loop%20Controlled%20Filament%20Dryer%20V3.doc?dl=0

If you run into any issues of have any questions, don't hesitate to contact me.

It's a really fun project and I hope a few of you take the time to give it a shot!

LulzBot

Mini

No

Yes

0.25

20%

In the writeup I describe where the support material is needed. I also specifically call out which parts need to be printed in ABS and which can be printed in PLA. rnrnABS is required due to parts that are located in the heated chamber.

The entire assembly instructions document can be found at the following link: https://www.dropbox.com/s/153k5ccl8jt00oq/DIY%20Closed%20Loop%20Controlled%20Filament%20Dryer%20V2.doc?dl=0rnrnThe document includes step by step directions and pictures on how to build your own filament dryer. rnrnIf you find any errors in wording, please let me know so I can update it quickly. I've had one other person successfully build a dryer so things should be pretty clear.