TODO / KOGAN / DEVANTI 250W dehydrator conversion to Filament Dryer Box system

This riser helps convert the TODO / KOGAN / DEVANTI 250w food dehydrator into a filament dryer (They're all clones - you may find more brands that use identical casing and trays):

https://www.amazon.com.au/TODO-Stainless-Dehydrator-Preserve-Yogurt/dp/B09Z68WGJ4

This can be easily achieved by snipping the bottom of the grates out of all but one basket in order to create a pseudo-wall around the outside of the unit, and then using these 4 printed risers to create enough height required to fit 4 spools inside - as well as add some needed features like Bowden adaptors and hygrometer.

This unit is designed to work in combination with my Ultra Low Profile 4-spool roller system here:

https://www.printables.com/model/1252898-ultra-low-profile-4-spool-roller

as the unit measures approximately 325mm across it requires a spool holder tighter than anything else available in order to fit 4 spool rollers inside. You are also welcome to use this system without any spool rollers and just use it to dehydrate filament only.

***EDIT***

Added Heat Spreader module to encourage heat to spread below the 4 spool areas, as the element heats directly upwards from the middle without it.

If you plan on drying PETG regularly at high temp, you may need to print the heat spreader in ABS as it will be taking continuous heat blasts and eventually soften.

Airflow is one of the most important factors in effective drying. You can do without it, but the centre of your dryer box will be very hot compared to the edges. The spreader does it's job effectively but please remember to rotate your filament every now and then to prevent the bottom from fusing.

PREPARATION

Remove 4 of the 5 baskets and clip out the mesh floor using cutters. Leave one basket as your base, and place desiccant packs in the tray underneath it.

On the basket being used for the base, remove the obstructive ring in the centre by clipping out just enough plastic around it, and remove it.

Print the 4 risers you desire, I have attached 3 versions for those with and without holes for bowdens / hygrometer.

Hardware required for the normal Bowden + sensor version:

• 1x standard embedded hygrometer / temperature sensor ( example: https://www.aliexpress.com/item/1005007097164320.html )

• ***EDIT*** 4x PC4-M6 pneumatic intakes (instead of the previously listed PC4-M10 connector without intakes)
  https://www.aliexpress.com/item/1005009606086798.html

• Bowden tubing

• Clear silicone (to glue the clear walls together)

• 4x PC4-M10 connectors (no longer needed)

• 4x M6 nuts (no longer needed)

***EDIT*** - the box Hygrometers will show an ambient temperature of approximately -10 to -15C of your set temperature, but the heated convection out of the element does sit at the set temperature - so be careful not to overheat your filament by raising temps too high. Convections are very effective at ripping the moisture out of the surface of your filament but it may take longer for the internal filament to dry.

***EDIT 2*** 28/06/26 -

It has been over a year since creating and using this system, and everything works well including the rollers. It is very effective at drying and I usually find that 55C for 1 hour is more than enough for immediate drying of PETG, and brings the box humidity down to about 15%. I am usually able to print PETG while it is drying without stringing. The TODO unit is showing signs of wear (the fan is slow to spin up from pressing ON) but for a $20 repurposed e-waste dehydrator, this thing has more than done its job for the money.

PRINT SETTINGS

PETG required as the box can reach a maximum of 70C (allegedly).

There are some critical settings in order to get this print working well, please read carefully the following.

Firstly, turn auto supports off. You do NOT need supports under the channel at the base, they will potentially ruin your smooth connection to the base. The only area that needs support is the humidity sensor hole, please paint it on manually for NORMAL SNUG support. 

Secondly, please check layer 26 (0.2mm Layer height) for the first bridge across the bottom channel. You may need to rotate the bridge to prevent long, unsupported bridging. try 90 or 180 degrees or so until you see short perpendicular bridges like this:

Thirdly, if you have bed adhesion issues, full brim on. 

If you have no bed adhesion issues, mouse ears. 

If you really, REALLY have no bed adhesion issues, mouse ears. Just do it, they're very tall and thin pieces that can not afford warping.

For the heat spreader, print upside-down and paint supports on manually, underneath only. DO NOT place supports inside the model, it doesn't need it and it will be impossible to remove.

Highly recommended to print this in ABS.

Please also double check your top surface bridges at layer 119 (0.2mm layer height) to make sure the bridges are short and perpendicular.

ASSEMBLY

The 4 pieces slot together very tightly. There is no clearance between connectors of each piece as the PETG needs to grip tightly to form a solid box, which it does this way. Early tests showed that clearance only made the box flimsy and require glue, so force those pieces in please.

Place the heat spreader directly on top of the element, no hardware needed.

Assemble and place the 4 risers on the first basket attached to the base. The channel will slide snugly into place, but not tight. Attach your PC4-M6 connectors by pushing the round end through the teardrop hole until the thread is completely through the other side (you may need to round out this hole using a drill or deburring tool if it's too tight). Connect the M6 nuts and tighten.

Attach the 4 hollowed-out walls on top for height, and add the lid. The unit is now assembled. (NOTE: I used clear silicone to glue the clear walls together as one cohesive unit)

The Bowden version will require my ultra low-profile filament rollers as I believe there is no other appropriate roller system available as of yet:

https://www.printables.com/model/1252898-ultra-low-profile-4-spool-roller

The unit claims to heat up to 70C, but I believe only the area near the element will ever reach this temp. The hygrometer only seems to go up to approximately 55C at the 70C setting, but in my testing the PETG sitting near the element was starting to melt and fuse, so it definitely is heating just not thoroughly. This is most likely due to it being a cheaper unit only designed to heat a smaller volume. It may be possible to insulate your unit for more thorough heating but for now I would suggest not going above 65C for PETG until I find a decent solution.

I may continue to update this project in the future with upgrades. The next thing to look at is combining the basket walls together to form a cohesive lid rather than loose pieces.