Polymaker - PolyDryer review
Why did we buy the PolyMaker PolyDryer?
We print a lot of hygroscopic filaments such as TPU, glass and carbon filled nylon that absorb moisture from the air and quite quickly when not adequately stored. Hygroscopic materials are notoriously challenging to print and can present difficulties such as poor extrusion and layer adhesion when “wet”, even when out of a brand new sealed box.
A wet filament means the raw material contains too much moisture. A tell-tail sign of your materials being “wet” is present whilst printing, bubbles (steam escaping the filament) with audible hissing and popping at the tip of your nozzle as well as within the print itself. Many manufacturers of such materials even recommend drying out your new material for several hours as soon as you open them for the first time.
For a number of years we have been running modified food dehydrators that was supposedly rated to heat up to 70°C. The modified food dehydrator served us well for some time whilst we mostly printed TPU. We recently acquired a Bambu Lab P1S in house and we wanted to print more carbon filled materials.
Our initial print results using our DIY drying method and using PETgCF showed ribbing and discolouration throughout prints. Even after tuning flow rates, nozzle temperatures and other parameters, we couldn’t get a significant improvement. We then decided to look into buying a new material dryer that reached a higher temperature and more compact than our old DIY setup that reached a maximum of 45 degrees.
At first it was a tough decision to make between the PolyMaker PolyDryer and the SUNLU S4. The S4 is capable of drying 4 rolls of filament at once and has an excellent track record from other users. However, it takes up a lot of desk space and cost roughly £140.00 compared to the £38 cheaper PolyMaker PolyDryer that only dries one roll of filament at a time, is quite new to the market, but is considerably more compact and modular! With very few reviews online at the time of buying, we were sceptical whether the PolyDryer would our requirements but we took the plunge and it was worth it!
PolyDryer features and out of box experience
When unboxing the PolyDryer combo, you receive the following;
PolyDryer dock / heating base
1x PolyDryer box with latching lid
2x airlock feet / seals
Filament spool holder
Hygrometer rectangular display (remove rear tab to power on display) and desiccant holder
Colour changing desiccant/silica gel beads
Filament PTFE feeding / guide tubes
Power cord with universal plug adaptors and user manual
You can dry up to a 1KG spool of filament from PLA, PVA, PETg, TPU and higher grade engineering materials such as PA. The spool holder is removable so you may be able to run slightly larger spools on the included silver rollers. The rods do cause some unwanted friction depending on the material your spool is made from and its dimensions, we tend to use the blue spool holder / rest with all brands so far due to reduced friction and noise. You can purchase additional PolyDryer boxes to store additional materials and dry them individually when required.
We were immediately impressed by the weight of the components which we were hopeful will lead to long lasting build quality and great results. All of the extra parts were stored within the dry box itself keeping the total packaging size to an absolute minimal. When first opening up and closing the lid of the dry box we thought we were going to break the lid or our fingers! The latches on the dryer box are too strong when first used, it has become a little easier to work with over the last 3 weeks of swapping between drying different materials.
The lid itself has a silicone seal that goes around the entire inner edge but only has filament outlets on one side, the same with the clear storage box itself. Before going into more detail, you can check out a feature overview video from PolyMaker below;
Polymaker PolyDryer feature overview video direct from the manufacturer.
With everything unboxed, we did immediately notice a rattle within the dryer dock. We had already anticipated stripping down the PolyDryer so we took it upon ourselves to void any warranty and take a look inside. Before dismantling we checked everything powered on and worked first which it did perfectly. There are only 4 screws that hold the unit together with no “warranty void” stickers or seals that we could see.
The rattle inside was a tiny piece of plastic from potential over moulding around the screw pegs (can be seen in the first two photos below). After giving everything a once over to make sure there were no cracks or damage elsewhere, the unit was re-assembled and functioned as normal.
The internals are quite simple and minimalist, housing an “efficient” 65W PTC heater, 24V fan, thermal breaker and NTC thermistor on the PCB for safety and the electronic controls. The heater system uses the fan to blow air through the heater out through the rear exhaust into the dryer box. The fan then draws circulates air back in through the front port of the dryer box. The feature video from the manufacturer makes it look like the moisture escapes the side holes in the dry dock, there is very minimal pressure from this though in person.
We personally find the fan to be a little under powered, as you will see later in our testing results, the dryer box is significantly warmer on one half compared to the other side. The parts used however do deliver a bearable noise level of only 64DB which you barely notice when your 3D printer is slinging away by its side. We do recommend you manually rotate your filament throughout the drying process every 1 to 2hrs so your filament is dried more equally throughout the entire spool.
Setup and use
The display of the controls is slightly disappointing, if you are standing above or off to one side from the machine the display blurs and is very hard to read however, as soon as you are eye level with the display everything is perfectly clear. You definitely want to read the manual on how to operate it properly before first use, but here is a brief “how to” setup guide of our own:
With everything plugged in and turned on, press the “M” (mode) button to cycle through the three heat levels
The silver sticker on the dryer dock shows you which mode suits each material type
The plus and minus buttons will increase or decrease the drying time in 30 minute increments
If you press and hold the “M” mode button for 4 seconds you will enable or disable continuous drying mode
Pressing the top left play/pause button will start or pause the heat cycle
If you press and hold the play/pause button, the machine will reset to quit the drying mode you are in and then allow you to set how hot you want it to run again
With your drying mode and timings all set, you can then add the included desiccant to the front storage compartment, add your filament and off you go. Just make sure you have removed the two airlock feat for clear box before placing on top of the dryer itself. You will also need to remove the white tag at the rear of the hygrometer to power it up.
We decided to use an alternative desiccant to fill up the container as much as possible. One online reviewer did state the included packet may not be the safest if ingested, with having two cats in the house and also making additional desiccant holders for the Bambu Lab AMS, we used Wisedry silica gel desiccant beads from Amazon. We also find the orange colour changing desiccant easier to spot when it needs drying out too and easier to find in the carpet…
As your filament dries out, bear in mind that the actual spool itself will also need to be dried too, especially if you use cardboard spools. The moisture level will rise rapidly in the first 2 minutes on the included hygrometer. We struggled to get a reading under 10% even after 24hrs of drying, we believe the hygrometer may be the cheapest component of the entire product as the figures bounce between 10 and 20% with no consistency no matter how long we ran the machine.
You can add the dryer box to the dock in either orientation as the inlet / exhaust ports are the same size, but if you decide to do this be careful as the expelled heat will eventually burn out the display of the hygrometer so try to keep that facing the front cooler side.
The lid of the dryer box can also be fitted in either orientation, we personally prefer to leave the hygrometer side on the cold side of the dryer, but have the filament outlets on the rear of the lid so it is a shorter and more direct path to the printer. This will prevent your TPU and other fragile materials from likely snapping in the feed path and less tension on the filament an extruder resulting in a cleaner print. We wish PolyMaker had mirrored the filament outlets on the dryer box and lid.
The included PTFE tubing is also very thick! The internal bore is considerably wider than the tubing you get on most 1.75mm FMD/FFF 3D printers. This used to be seen as a poor choice especially with flexible materials due to the chance of build up in friction and binding with softer materials. Fortunately so far, we have not had any problems with this, we did have to 3D print an adaptor so we can connect the PolyMaker tubing to the standard size that the Bambu Lab P1S uses on the rear of the machine.
testing & results
Considering the price of the PolyDryer, we were surprised to see there is no data output of the actual temperature the machine is producing when drying or recording the moisture levels. For testing purposes we purchased a Dual Channel Digital Thermometer to test exactly how much heat the dryer dock generates and for future testing of other equipment.
We generally found that the heating mode maxed out to it’s inbuilt set figures within 30 to 40 minutes of being turned on. These figures will vary depending on your ambient temperature or your print environment. We set up the PolyDryer in a home office environment with an ambient temperature averaging 24°C throughout the testing period. We placed a K-type thermocouple sensor inside the dry box at the rear and front of the filament roll roughly 2 inches above the heater outlet and cool inlet, we recorded every 10 minutes for upto an hour to gather the average date presented below;
Mode 1 - 40°C hot side, 35°C at cool side of box
Mode 2 - 48.2°C hot side, 41°C at cool side of box
Mode 3 - 56.7°C hot side, 47.7°C at cool side of box
There is on average of 5 to 7°C variance on all power / heating modes between the hot and cold side of the spool. With quite a substantial difference in temperatures and purposefully buying this device to treat sensitive materials, we would advise you rotate the spool every 1 to 2hrs so your filament is dried as evenly as possible. Doing so will improve your print quality consistency, especially on bigger prints.
We decided after collating the data to position the hot side sensor closer within the heat exhaust port itself. Once positioned directly inside the exhaust the maximum temperature recorded was 65.3°C in the hottest drying cycle however after 12+hrs of testing, the box itself has never exceeded 60 during our ownership. The photos below show our testing setup and peak power consumption of 86W. It would very rarely drop and qould quickly rise back to 75W+ when in the hottest heating mode.
As seen with other pre-release video reviews, the silver sticker that shows you the modes and guidance on setting the unit up also bubbled on our unit within 20 minutes of using it for the first time. Others have also expressed how annoyingly loud the beep is on the machine when it first turns on and when setting the machine up. It is bearable, but it is also important to be so loud so you know when the timer has finished so you can fit the airlock feet as quick as possible.
Left part is after drying out the material, right part is dried out using our old DIY method showing inconsistent extrusion and moisture content.
With the dry box used as a storage unit and over a period of roughly 2 weeks the hygrometer goes up by 7 to 10%. Fortunately, you don’t need to go drying your material for 12 to 24hrs before every use if you ensure your seals are properly closed.
Shorter “maintenance” heating cycles are only really required unless it has been a good month or two, then you may want to do a full heat cycle before your next print. If you are printing through material faster than other users, then you will probably benefit from having multiple dryer docs and boxes more than the average home user.
The print quality has far exceeded our expectations now when using PETgCF. For this test we specifically used affordable ERYONE PETgCF to improve the aesthetics of several Airsoft components. Before pursuing an improvement with the drying of our materials, we had optimised the flow rate, nozzle temperatures and speeds with no improvement. Once we had properly dried out the material and re-calibrated the Bambu Lab P1S for our new material of choice, the results speak for themselves.
We have additionally dried out TPU and normal PETg and the visual quality of prints and layer adhesion far exceeds our older DIY setup on any machine we now print with from the PolyMaker PolyDryer. You can see more photos of our prints at the end of this blog post.
Conclusion
The PolyMaker PolyDryer has done exactly what we were looking for! It runs 10 to 15 degrees hotter than our DIY setup and as a result, we’re achieving flawless PETgCF prints. The compactness, ease of use and modularity should you ever run multiple dry boxes as a storage solution is great. People have already produced adaptors to dry two boxes at once and create wall hangers for the boxes plus other modifications as seen below.
3D printable accessories for PolyMaker PolyDryer
The main improvements we would like to see on a future generation of this product is:
Faster heat up times
See a more balanced heat on both sides of the spool
Digital read out of temperature and moisture levels
Reduce the strength of the locking mechanism of the lid levers
Mirror the filament exit options to have on both front and rear of the lid and box itself
Considering the average retail price of this product and compared to it’s rivals on the market, most of the above features should have really been there for day one of release. However, considering the compactness and the fact we now have flawless prints with our range of more hygroscopic materials, we can live without them for now. The modularity of the product probably makes up most of the higher ticket price currently.
Our rating of the PolyMaker PolyDryer solution is:
Price point - 3.5 stars
Usability - 4 stars
Performance - 4 stars
Design / product completion - 3.5 stars
We purchased the PolyMaker PolyDryer from Additive-X which was a very straight forward and fast buying and delivery experience. After a few weeks of testing the product and collating data, there are signs of other UK sellers potentially getting a hold of these units too. We hope you’re enjoyed this blog, to finish off the post here are a few prints we’ve had success with since purchasing the PolyDryer and using PETgCF as the material of choice;
