When left out in the open, 3D printer filament can absorb moisture from the air. “Wet” filament can ruin our prints, and thus this is something that we want to avoid.

In order to prevent filament from absorbing moisture, we need to properly store it. This means we have to keep it in a humidity-controlled environment, such as a filament storage box.

Recently I bought some extra colors of PLA filament for the IKEA ALEX label & handle system and for several other upcoming projects. In order to keep the filament dry I decided to build filament dry boxes out of IKEA SAMLA storage boxes.

Front view of an IKEA SAMLA box containing yellow, orange and red 3D printing filament spools.
One of the filament storage boxes.

The shaft in the storage boxes is mounted on bearings. That way I can use the boxes not only to store the filament, but also to directly print from them. The rotating shaft allows for less friction when feeding the filament into the extruder.

Close-up of 3D printed components inside of an IKEA SAMLA box, with two attached 608-RS2 bearings supporting a PVC pipe.
The roller bearing system. It uses 608 skate bearings to support the shaft that holds the spools

In this article I will show you how to build your own filament dry boxes, so that you can keep your filament dry.

Before explaining how to build the filament dry boxes, I would like to give some more information on the relationship between filament and moisture:

How and why does 3D printer filament absorb moisture?

3D printing filaments such PLA, ABS, Nylon and Polycarbonate consist out of polymers. These polymers are hygroscopic, meaning they have a strong tendency to attract moisture. This moisture is typically absorbed from the air.

Why do you need to keep filament dry?

Wet filament can cause a variety of problems. For example, PLA becomes very brittle and can snap when it only gets bent a little. Wet nylon filament can turn opaque instead of transparent.

Some other problems that can occur with wet filament are:

  • 3D prints have a rough finish texture.
  • Reduced part strength.
  • Extruder jams.
  • Reduced print bed adhesion.
  • A lot of stringing.

How can you prevent filament from absorbing moisture?

The best way to keep filament dry is to limit the exposure of the filament to air. This is done by storing the filament in a sealed environment.

For hobbyists, the most affordable solution is to keep the spools in an air-tight container. Adding desiccant to the container will help keep the air and filament dry.

What to do when filament is already moist?

Your filament can still be saved if it has absorbed a lot of moisture. You can do this by exposing the spool of filament to dry, hot air for a prolonged period of time.

There are several ways to do this:

  • Drying the filament in an electric oven.
  • Using a dedicated filament dryer to dry the filament.
  • Drying the filament in a modified food dehydrator. Food dehydrators often contain plastic racks that can be removed to create enough space for a spool of filament.

The filament drying temperature varies, depending on the type of filament. You want the temperature of the air to be lower than the glass transition temperature of your filament. That way, you don’t overheat the filament and cause the filament on the spool to melt together.

It is recommended to dry the filament for three hours or longer. Both the filament on the outside and on the inside of the spool need to have enough time to get rid of their moisture.

Read on to learn how to build the IKEA SAMLA dry boxes to keep your filament dry.

Materials (per box)

Tools

3D Printed Parts

  • 2 x Base
  • 2 x Back Plate
  • 4 x Bearing Retainer
  • 1 x Drill Jig
  • 4 x Lid Clip

The .STL files for 3D printing are available for download on Thingiverse.

The included drill jig is for 22L / 6 Gallon SAMLA boxes. With some accurate manual alignment it should be possible to mount the parts on larger SAMLA boxes.

I printed the parts with 2 shells, 25% infill. The printed parts support a lot of weight from the filament spools so I do not recommend printing them with a lower infill percentage.

The bearing retainers need to be printed with support material.

How to build the filament dry boxes

A 22L IKEA SAMLA box with red 3D printed parts for a spool holder assembly placed next to it.
Prepare all parts. Make sure to remove any support material from the 3D printed parts.

Drilling the holes in the SAMLA box

An upside down 22L IKEA SAMLA box with a red drill jig placed on top, with red 3D printed components next to it.
Place the drilling template on the SAMLA box. Flip the box upside down and center the template on one of the short sides of the box.
A power drill drilling a hole in a 22L IKEA SAMLA box using a 3D printed red drill jig as a guide.
Drill the first hole. Hold the drill jig securely in place while drilling.
A power drill drilling a hole in a 22L IKEA SAMLA box using a 3D printed red drill jig as a guide.
Drill the second hole. To make sure the drill jig does not shift, you can secure it in place with one of the M4 bolts and a M4 nut.
Four evenly spaced drilled holes in an IKEA SAMLA box.
Drill the remaining holes. The result should be four evenly spaced holes.

Assembling the 3D printed components

A hand holding a M4 bolt with a red 3D printed bearing retainer slid over it.
Slide one of the bearing retainers over a M4x30 bolt.
An M4 bolt with a red 3D printed bearing retainer and a 608 roller bearing slid over it.
Slide a 608 bearing over the bearing retainer.
Two M4 bolts with a 608-RS2 bearing and a red 3D printed bearing retainer slid over each bolt.
Repeat the previous steps for the second M4x30mm bolt.
A hand holding a 3D printed base plate for a filament storage system, with two 608-RS2 bearings attached using M4 bolts.
Insert the bolt/bearing assemblies through the bottom holes in the base plate.
A hand inserting red 3D printed components for a filament storage system into an IKEA SAMLA box.
Place the base plate on the inside of the box and insert the bolts through the drilled holes.
A hand tightening a nut over a bolt that holds together 3D printed parts of a filament storage system assembly.
Add the back plate on the outside of the SAMLA box and secure the two M4x30mm bolts with the washers and nuts. Do not over-tighten the nuts.
A red plastic assembly that is attached to an IKEA SAMLA box with M4 bolts and nuts.
Insert the M4x16mm bolts through the top holes and secure these with two M4 nuts.
An open 22L IKEA SAMLA box containing two red 3D printed assemblies with bearings.
Repeat the above steps to mount the second base plate on the other side of the SAMLA box.
An exploded view of a low friction filament storage assembly that consists out of 3D printed parts, bolts, washers, nuts and roller bearings.
The exploded view of the entire assembly.

Cutting the shaft

A hand using a hacksaw to cut a grey PVC pipe that is clamped in a vise.
Cut the pipe, rod or shaft that holds the spools to the proper length. For the 22L SAMLA box it needs to be approximately 296 mm long.

Inserting the filament spools

An open IKEA SAMLA box with in it yellow, orange and red 3D printing filament spools on a PVC pipe.
Insert the pipe through the spools and place it on top of the bearings.
A closed IKEA SAMLA box with in it yellow, orange and red 3D printing filament spools on a PVC pipe.
Place the clips on the lid to make sure the box stays as airtight as possible.
Three IKEA SAMLA storage boxes containing colorful 3D printer filament spools.
The three boxes I built.
A corexy 3D printer made out of Makerbeams with integrated in it an IKEA SAMLA box containing filament spools.
One of the SAMLA filament dry boxes mounted in the old 3D printer.

The final step is to drill some small holes in the SAMLA box that allow the filament through.

Depending on how you plan to use the box, you can drill the holes either in the lid of the box, or in the side.

Alternatively, you can take the lid off when printing with the filament, as pictured in the image above. This does expose the filament to more moisture however, so this is not ideal.

Adding silica gel desiccant to keep the filament dry

Update 28/06/2019

I have added reusable silica gel beads to the filament storage boxes to help keep the filament dry. While the SAMLA boxes reduce the amount of air the filament is exposed to, they are not 100% airtight. As a result, there is still some moist air entering the boxes.

The silica gel beads adsorb the moisture from the storage boxes, so that only a minimal amount ends up in the filament.

A transparent container with 1 kg of reusable orange silica gel beads that can be used to keep 3D printer filament dry.
A 1 kg container of reusable silica gel beads.

What does the silica gel do exactly?

The silica gel beads adsorb moisture from the air inside the filament box. In turn, the filament has less moisture available to absorb and stays dry for a longer period of time.

How can the silica gel beads be reused?

As the silica gel beads adsorb moisture, they change color to indicate their level of moisture saturation. The orange silica gel beads turn green over time, and the blue variant turns pink.

When you notice the beads have changed color and are saturated with moisture, you can reactivate them by placing them in an oven or microwave for a while. This removes the moisture from the beads.

After this, you can put the beads back with the filament. This cycle can be repeated many times with a single batch of silica gel.

Is it expensive?

Not at all. Reusable silica gel is very affordable. Especially when comparing it to the cost of moist filament that might has to be thrown out, the time spent on solving print issues due to moist filament, etc.

How much silica gel should you use?

I use about 250 grams (~ 1/2 lb) per filament box. This covers the floor of the 22L IKEA SAMLA boxes with a generous layer. So far this has been working well.

An IKEA SAMLA filament storage box with a layer of reusable silica gel beads to keep the filament dry.
250 grams of silica gel beads on the floor of one of the dry boxes.

Does it actually work?

I was curious about this as well, so I decided to log the relative humidity (RH%) in the filament boxes in order to get some actual data.

A plot showing the humidity in a filament box after adding silica gel.

It took about 10 minutes after inserting the silica gel for the humidity to drop to a minimum level of 10%. Even now, after a couple months, the humidity sensor still indicates 10%.

I should note that the humidity sensor I use only goes down to 10%, so it is likely that the RH% in the boxes is even lower than that.

Either way, the humidity in the boxes has significantly dropped since adding the silica gel beads.

From a more subjective standpoint, I don’t seem to have any printing issues due to moist PLA anymore, so it is safe to say that this works.

How often does the silica gel need to be dried?

That depends on the circumstances. The main factors that influence it are:

  • The humidity of the environment.
  • How well the dry box is sealed.
  • How often the dry box is opened.

That said, I added silica gel balls in the boxes two months ago and they have only discolored a bit so far.

The environment the boxes are in has about 50% humidity, and I do not open the boxes that often.

Conclusion

The filament dry boxes in combination with the silica gel beads work very well. With this setup I haven’t had any printing issues with PLA anymore. So far the PLA remains flexible, prints without bubbles, with little stringing and with a smooth finish.

I must say that the SAMLA boxes are not a 100% ideal for this purpose, as they are not perfectly sealed and still let in some air. But for the budget I spent on it, I am quite happy.

If you find this article useful, please share it or leave a comment. I love to hear your feedback and questions!

6 thoughts on “DIY Filament Dry Boxes”

  1. Looks as a good cheap system.
    The humidity dropped very, very quick. Not strange because you use a lot silica in a small place.
    Do you have the idea or experience that it wil dry PLA that was stored looong time at the wrong place ( just on a shelf in the living)?

    1. Hi Tor! I think that if you want to dry moist PLA filament you will have better results with a filament dryer.

      These storage boxes work best for keeping dry filament dry.

  2. Built this up yesterday – works really well! First proper “project” with my printer with a real use. Cheers for the great instructions. 🙂

    1. Hi Niall,

      I am glad it works well for you. Good luck on your 3D printing journey and thanks for the comment!

      Tim

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top