Dehydrator to Filament Dryer DIY, Don’t Toss Wet Filament!

Do What Now?

This tale is about turning your average food dehydrator into a 3D filament dryer.  Storing hygroscopic filament correctly is very important.  Hygroscopic means that the filament can absorb moisture from the air. 

I store all of my filament, even my PLA, in lockable totes with foam seals and desiccant packs.  If you’ve ever had a water logged roll of filament ruin your day, read on and prepare to be amazed!

Sadness Strikes!

Regardless of how I have been storing my materials… something terrible happened.  My Ninjaflex TPU filament absorbed water.  As I was heating up my hot end on my ever so reliable and slightly modified Tevo Black Widow, I heard the tell tale signs that something was amiss.

 There was some slight sizzling and a couple of weird popping noises.  Instead of a solid stream of filament slowly streaming out of my nozzle, I was greeted with a sputtering bubble of liquid goo.

Whelp, that’s depressing!  I needed to finish the printable joints on this new 3D printed hand that I was printing.  After lowering the temperature of the filament 10c from what I normally print at, the filament started to look a little better when extruding. 

I decided to push the print job through regardless of the printing temperature and hope for the best.  The job managed to finish and the part seemed strong.  The surface quality was rough and textured.  Not the smooth finish with almost invisible layers that I am used to seeing in my prints.

I decided at this time to check the other hygroscopic filaments in my possession.  Both rolls of Ninjaflex TPU, two rolls of PETG and my roll of Nylon were both water logged messes.  So now, I had three options.

Count Your Losses?

Option 1: Toss the materials and next time try harder at not being terrible at storing my filaments.  The problem with that, is these materials aren’t really cheap.  If I were to just toss these in the bin and count my losses, I would be out over $100 in filament.  UNACCEPTABLE!

Bite The Bullet?

Option 2: Buy a filament dryer.  Well, there’s a perfectly good solution to every problem… buy the thing that solves it.  In this case it’s a device that costs over $100.  Well, spending $100 to save $100 isn’t the best math for bargaining a purchase.  Yes, it does have the benefit of stopping this problem if it every rears it’s ugly head again.  The problem is, sometimes $100 just isn’t in the budget.

Do It Yourself!

Option 3: DIY.  Yes, this is more up my alley.  I decided to simply listen… ‘Run What Ya Brung’.  Essentially, this means to find something around the house that suits my purpose.  Sadly, the minimum temp on our oven is 180F/82C.  In an effort to stay far below the glassification and melting temperatures of my filament, this is too high.  We also have a small toaster oven, and the temperature range is good for drying.

The problem is the size of the toaster oven. The complete filament spools will not fit in there.  I didn’t want to have to try and measure what would be needed, cut it off and just dry that.  I wanted my filament dryer to be able to dry the whole spool at once, and that’s when it came to me..

A food dehydrator!  It’s circular, can be modified to fit entire rolls of filament, steady stable temperatures and most importantly… it’s cheap!  It’s temperature range also match up nicely with all of my materials.  My amazing wife forbid me form mutilating ours… so I went on Amazon and got the highest rated unit in my price range.  I’m not a ‘Prime’ member, so it took four days to get to me.  Now comes the part you all have been waiting for…

The Build Materials

What you will need to make your DIY Filament Dryer:

• A food dehydrator big enough to fit your filament spools
• A set of side cutters
• A file
• Safety googles and gloves

Safety!

I am sure that you noticed the last couple of things on that list… safety apparel.  It’s a requirement.  You don’t want a razor sharp piece of acrylic flying into your retina and permanently blinding you… all in the name of 3D printing.

After making sure you have everything you need, make sure your dehydrator will fit the filament in it.  We want the total height of the racked area to fit your spool.  After all of this is checked, let’s start cutting!

Let’s Destroy a Dehydrator!

1. First, set aside one rack from the dehydrator.  This will be our base rack where the filament sets.  The rest will be chopped up and used as risers for the lid to clear the spool.
2. Start clipping and work your way around the rack.  Mine went really easily and each rack took under 2 minutes.
3. After you have the rack bottoms snapped out, use the file to clean up and sharp edges remaining on the inside of the rings.  You don’t want to accidentally lose a digit.
4.  Stack the cleaned up rings on top of the the untouched rack and place the whole thing on top of the dehydrator base.
5. Lay the water logged spool inside of the modified dehydrator.
6. Set the temperature and let it sit for the appropriate amount of time. Remember, the listed values are MINIMUM times.   (Check the table at the bottom of the article)

Conclusion

So, the moral of this story… proper storage of your filament is key.  Make sure you are storing your filaments in the proper containers with fresh desiccant packs.  When using nylon, water absorption is almost unavoidable.  It literally wicks water out of the air as you are printing!  Some filaments are less susceptible to water absorption, such as PLA.  Using this dehydrator or any kind of filament dryer will improve your print quality and your printing experience. 

Satisfied?

If you feel like you learned something or you like what I have done… let me know!  Any donations made to my PayPal go towards the printing and shipping of assistive devices that I am donating to people all over the world.

Drying Chart

Here’s the temperatures and drying times taken DIRECTLY from PrintDry.com: