Todd Pearsall

Now that we have a great solution for keeping our filament organized and dry what do we do for filament that has absorbed some moisture somehow? 

It has possibly been sitting around for a while and even a dry box that hasn’t had its desiccant drop down or maybe even a roll that came from the manufacturer damp.  You may find the role you’ve had for a while just isn’t printing as well as it used to. Might be time to dry it.  Each manufacturer has different recommended temperatures for drying their filament types. Be sure to check for your filament to avoid possibly ruining it.

I have tried a variety of methods to dry filament as I came to my current solution that seems to be working well.

1. Buy a cheap filament dryer.
2. Put it on your printer heat bed covered to trap the heat.
3. Put it in the oven.
4. Modify a food dehydrator.

Let’s walk through the options and I will share my experience:

Cheap Filament Dryer

Most of the low-end dry boxes are rated for up to 50°C and mine struggles to get within 8° of that. This is fine for PLA based on most guides but too low for almost any other material.  I still use it for printing materials like TPU Which can absorb moisture in the time it takes to complete a large print.

Conventional Oven

This is popular option. It works well as long as your oven has a low enough temperature setting to not damage low temp filaments.  Ovens also tend to heat above their target temperature and then cool to just below the target temperature. This is fine as long as it doesn’t go high enough to damage the filament.  My hesitations with this approach are 1) I haven’t measured it but worry about power draw leaving the oven on even a low temperature for 8-12 hours and 2) the side eye my significant other gives me when I’m cooking plastic in the place we prepare our food

Heated Print Bed

I’ve only tried this couple of times. Let’s start by heating the print bed up to the desired temperature for drying the filament, placing the filament on the bed and then covering it with the filament box with a few vent holes poked in it.  This works best in an enclosed printer to help keep the heat in.

At the time I initially tried this I didn’t have a good way to measure the temperature inside the box drying the filament. I also didn’t like tying up the printer for 8-12 hours for the drying.

Food Dehydrator

This is my current preferred approach. I purchased a popular inexpensive food hydrator that is rated for 70° C. From there I printed 2 risers to create the clearance for the filament spool. Similar to the cheap filament dryer it falls several degrees short of it’s rated temperature, but it appears if I leave it in an hour or 2 longer it will reach the same level of dryness. 

In several tests before drying the filament my dry box (link) reported 30 to 35% humidity. After drying the filament and returning it to the dry box it was reporting 10-12% humidity after the hygrometer had time to settle.

Components:

• Amazon: Commercial Chef Food Dehydrator
• 3D Model: Filament Dryer Risers

Warning on Reused Spools

If you reuse spools and buy refills like I do be sure the spool can handle the drying heat required for the filament.  For example, the standard spool from Bambu Labs is rated for less than 70°C, they have high temperatures spools for materials like ABS/PA/PC rated to 90°.  If you are using the spool that came with the filament you should be fine.

Some filaments are more hygroscopic than others meaning they more readily absorb moisture from the air. TPU and PVA are some of the worst, but PLA and ABS can also become moist especially if they have been sitting out for months or possibly even just weeks during humid times of the year. When printed moist filament can be stringy and have bubbles were bumps in the print layers. Sometimes you can even hear a popping as the moisture evaporates going coming out of the hot end.

I initially tried using vacuum storage bags with desiccant pouches in them. The storage bags kept the filament dry but were inconvenient to reseal when I was done printing. For filament I don’t use often this is an easy and cost-effective method of storage.

I couldn’t be happier with the solution I’m using for my everyday filaments; it keeps them dry and organized.

Components needed:

• Amazon: Air tight cereal boxes (others may work, but this one definitely does)
• Amazon: Mini Hygrometer (others may work they seem pretty standard)
• Amazon: Desiccant Beads (any desiccant beads will work)
• Amazon: CA Glue (any CA will work)
• 3D Model: Spool and Desiccant Holder
• 3D Model: Backing for Drybox Quick Swap Filament Labels
• 3D Model: Quick Swap Filament Label for Drybox

Steps:

1. Order the Amazon stuff you need. Most of items can be interchanged, the cereal boxes need to fit to the shape of the holders which I had a tough time finding.
2. Print spool and desiccant holder. PLA, PETG or ABS all should work just print both pieces with the same material, so they shrink the same amount.
   
3. Print the backing for the labels that will be glued to the containers. You will want 2 for each container, 1 for the filament brand and one for the type. For extra organization you could include a 3rd for the color. I used PETG but PLA and ABS should work but use the same material for the backing and label. I’d recommend printing 1 backing and 1 label and test the fit with your material of choice before a mass printing. You want the pieces to have some friction to keep the label from sliding off on its own but not so much that you risk pulling the backing off the cereal box.
   
4. Print the labels. You do not need to the print the base plates, only the labels you want. I found it easiest to use the blank label and add the text in the slicer since every filament brand and type isn’t covered.
5. Attach the label backings. Apply a big drop of CA glue on the center base plate and then attach to the dry box with tape to keep it in place while it dries. You’ll wanted the arrow to point to the left for the labels to slide on correctly.
   
6. When the CA glue is completely dried test fit the labels.
7. Fill the spool holder with the desiccant beads and slide the cover on.
8. Crack open a beer or beverage of your choice and admire your work.

I’ve been playing with 3D printer for a about a year now and it’s been great! I’ve printed lots of cute trinkets, articulated dragons, Pokemon and all the other neat stuff you can download and just press PRINT. I think it’s a law for all new 3D printer owners to go through that phase. My real interest, however, is using CAD to design and functional things. These are designs that solve problems, fix broken things or improve stuff I have.

I created a 12″ piece of baseboard molding that matched a corner section that was damaged during a bathroom remodel.

There is a failure point on the Lotus Elise marker light where it clips into the body. Rather than replace the whole housing which are getting harder to find I created a clip that wrapped around the broken stub and used epoxy to attach it. 10 track days later and it is holding strong!

My Roomba couldn’t clear the threshold between the living room and the kitchen so I designed and printed a ramp to smooth the transition.

The latch on the passthrough from the cab to the back of my ambulance converted to an RV broke and the replacement was $150, so I created a new design that work great.

Too many others to list, but just examples of things that were fun to design and solved a problem. None of these items were of any use to anyone but me with a few exceptions. These exceptions are what drove me to open an Etsy shop. It is very low cost to do and I was curious if anyone would actual buy some of the items that I found useful.

I am somewhat obsessed with storage and everything having a proper place. Let’s not even start the trauma I go through when it’s time to replace a laptop bag. This need for organization is what lead to the shop name of A Spot for Everything. We’ll see if that name continues to fit as more items are added.

Items for far:

Trac-Com Intercom Hard Case
Viture One and Pro XR Glass’s Cable Organizer
Fuel Filler Bib

(Also adding external links to your store and items helps with Google SEO)

Oven: .5-2 hours at 250 degrees
Microwave: 10min on defrost

This is the item I use: https://amzn.to/3xgGh8H

Noting this for when I lose the empty container.

Weight of the spools I’m using so I can calculate remaining filament and hopefully not run out in the last 5% of a print.

Component	Description	Weight
	Bambu Lab White Empty Spool	~210g
	Bambu Lab Transparent Empty Spool	~219g
	Cardboard Spool Core or Spool Adapter	~37g
	Filament Clips	~1g each

For the white spool with clips subtract 251g from the weight to get the remaining filament.

For the transparent spool with clips subtract 264g from the weight to get the remaining filament.