One of the biggest advancements in FDM 3D Printing has been towards innovative material development. In the early days of desktop 3D Printing we were confined to printing only ABS and PLA but thanks to companies like Polymaker (PolySmooth, PC-Max, PolyMax PLA) we have new innovative materials specifically designed for end use functional parts.
Materials like PVA, Nylon and PolySmooth are all highly hygroscopic; which means they rapidly absorb moisture from the air. This moisture expands as it passes through the hot end causing significant issues from very poor surface quality (inconsistent extrusion, bubbling) to low mechanical performance (poor layer adhesion). Other materials like PLA, ABS, PC and PETG are also hygroscopic but won’t absorb moisture at the same rate as PVA for example.
Moisture damaged filaments 'bubble' as they extrude, causing a variety of printing issues when trying to achieve quality and strong 3D Prints
With these advanced and optimized 3D printing materials, surprisingly there hasn’t been many attempts to create a product that protects these materials. Traditionally if I wanted a dry box I would have to use my 3D Printer and my lacklustre DIY skills to pimp out a cheap storage box. Maybe I'm in the minority but I bought my printer to print projects and enable my creativity not to constantly print new parts like spool holders and adaptors for my printer, plus all the DIY dry boxes are always ugly and bulky, no offense.
When Polymaker advised me that they had developed the PolyBox, a dry storage box / spool holder that protects hygroscopic filaments from moisture, I was excited to test it. I personally don’t like leaving my filament out overnight and I always store my filaments in resealable bags when not in use. The PolyBox should protect my filament during printing and as a bonus its not an ugly bulky box.
With a prototype spool of Polymakers Nylon and the PolyBox dry box, I was ready to dive in to see how Polymakers second hardware product performed.
Unboxing & Set Up
Assembly of the PolyBox was minimal as the Thermo-Hygrometer and rubber plugs are pre-installed. All I had to do was install the steel rods (which involved sliding the bearings on the four rods and snapping them into place), install the battery into the hygrometer and place the set of two desiccant packets in the PolyBox.
The PolyBox came with a long filament guide tube which Polymaker recommend cutting to match the distance between the PolyBox and printer. I just cut mine in half so I can use my PolyBox with two printers at a time.
The manual didn't really describe the best way to load the filament so when I first started using the PolyBox with two printers I was finding it was awkward to load and remove filament. This was because I was actually holding the transparent cover with my right hand during the whole process which as you can imagine involved some co-ordination. This method was completely unnecessary and by using the following method below, loading and unloading filament in the PolyBox is incredibly easy.
- Move the PolyBox to ensure enough room at the back or front of the table (the direction you move the PolyBox will depend on if your rubber plugs on the cover are facing forward or backwards)
- Take off the transparent cover and place it on the table with the rubber plugs facing up.
- Place the spool in the PolyBox and feed the filament through the rubber plug.
- Place the cover on the PolyBox while pulling the filament (to avoid unwinding) and install the filament guide tube.
Protecting filament from moisture and dust
The PolyBox stores two large silica gel packets in the base of the unit which absorb moisture inside the PolyBox, lowering humidity to as low as 10%. A humidity below 15% is the optimal environment for storing hygroscopic materials. Polymaker provide four of these silica gel packets which gave me a spare set to use when I would eventually need to recharge my silica gel.
There is some slight monitoring required when using the PolyBox and this is where the precision-hygrometer is extremely helpful. As the silica gel packets absorb moisture, they will over time begin to reach their drying capacity. In environments above 20% humidity, moisture will start to rapidly absorb into the filament. The manual states that when the hygrometer reads above 20%, I need change my silica gel packets with my spare set and recharge the old ones.
So how long do the silica gel packets last before they need to be recharged? The answer will vary depending on how often you are changing spools in the PolyBox, the external humidity and how long you keep the lid off the PolyBox during spool loading. After using the PolyBox for three months during an Australian winter, the silica gel packets would last an average of three weeks.
To restore the silica gel's drying capacity, Polymaker recommend placing them in a convection oven at 80°C for 8 hours. The PolyBox has no proprietary components so it is possible to use other silica gel packets in the PolyBox such as microwavable silica gel, this would be beneficial for people who don’t have access to an oven capable of low temperatures.
With exciting new Nylon materials on the horizon, filament storage solutions like the PolyBox take away the worry and stress of printing / managing hygroscopic materials!
I often left my spools of PolySmooth and Polymaker Nylon in the PolyBox for extended periods of time and as I expected they have yet to exhibit signs of moisture damage. Like Polymakers first hardware product the Polysher, I appreciate that Polymaker once again followed a design methodology that favoured simplicity and ease of use. Using silica gel packets may be simple but they work effectively. Other methods such as active heating would have required user knowledge of material glass transition temperatures, would have drastically increased the price of the product and electricity would have been an on going operation cost.
On many 3D Printers the spooling system seems like an afterthought. With no standardised spool width or diameter, many manufacturers decide to solely focus on supporting their custom sized spools. You can see this with printers like the UP Mini 2 or the FlashForge Dreamer, which won’t hold 1kg spools, requiring an afterthought 3d printed spool holder.
On other printers the spooling position can be undesirable, printers like the Ultimaker 3 hold their spools on the back of the printer, this can be suitable for some work environments, but in small tight workspaces accessing the back of the printer can be difficult.
Anyone who has dared to search “spool holder” on thingiverse will find hundreds of custom spool holders, this shows how common this problem is.
Was the PolyBox the one spool holder to rule them all?
The PolyBox is capable of holding up to two 1kg spools or one 3kg spools and the PolyBox was compatible with all the spools I tried, including my small 250g spools. Polymakers solution to supporting the vast selection of spool diameters is to have the spool loaded on bearing clad steel rods. With the spool sitting on these rods, I don’t need to worry about the inner diameter of my spools anymore, this solves all of the typical compatibility issues.
More often than not when you start a new spool, the filament will unravel over the spool, 'tangling' around the common spool holder design. I'm not sure if Polymaker had this problem in mind when designing the spooling system but with the PolyBox the filament cannot physically do this as the spool acts as a 'rail' keeping the filament from coming off the spool. I find this is a nice benefit of the PolyBox spooling design.
On traditional spool holders, full spools can unwind and the filament can tangle on the spool holder.
The six filament exit points on the PolyBox along with the reversible cover make it easy for me to use the PolyBox with my different printers as each printer has different feeding points. Each exit point has a rubber plug that works effectively, minimising air from leaking into the Polybox.
With the PolyBox, printing hygroscopic materials like Nylon was incredibly easy and stress free.
The PolyBox is a no-nonsense, compact and effective solution to a problem that has made printing hygroscopic materials like Nylon and PVA notoriously difficult. Perhaps I could save a few dollars by making my own dry storage box however the storage boxes that are commonly modified are always bulky, require designing, 3D printing and depending on the design, struggle with the same issues as typical spool holders. I would rather spend my time on cool 3D Printing projects and use a ready to go solution like the PolyBox. For me a DIY dry box will take up more space, time and won't be as versatile.
The lack of a heater cartridge may disappoint some however the PolyBox worked perfectly without active heating so I think including one would have just unnecessarily increased the price of the product and dramatically increased operating costs.
The ability to print Nylon materials without stress really opened up the possibilities of my printing projects. I definitely plan on setting up a second PolyBox so all my 3D Printers are Nylon-Ready for the release of Polymakers new upcoming Nylon material.
Australians can purchase the PolyBox from their favorite 3D Tech Supplies reseller.