Food Dehydrator on Steroids

Update: As a preparation to be able to print directly out of the filament dryer, I designed a new roll adapter, which features a push-to-fit pneumatic adapter. Though this one, a PTFE tube (ID2 OD4) goes through the wall of the dryer, allowing the filament to exit it. Next, I will design a lazy susan to allow for the filament roll to spin freely inside the dryer.

Fot this you need a M6 pneumatic adapter (make sure to use a passthrough version!) as this one: https://www.aliexpress.com/item/1005004320606025.html

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My food dehydrator (which I actually bought to dry filament for my 3d printer) was not able to reach its advertised top temperature. Instead of 80°C, it maxed out around 60°C, reached after around 1h (starting at room temperature). So I decided to open it up and fix it. 

I removed the original lame bimetallic thermostat with the following:

• a PID controller (40x40mm PT100 SSR): https://de.aliexpress.com/item/4000048614441.html
• a SSR (40A and a matching cool-block): https://de.aliexpress.com/item/1005003639593518.html
• a PT100 temperature sensor (1m): https://de.aliexpress.com/item/4000216281626.html

Of course, you need a food dehydrator. I used Sencor SFD 970WH because it was cheap enough, while still having enough power to reach 80°C (used for some technical filaments), but in principle you can use any other dehydrator - but my printed parts will have to be adapted ;)

I re-used one of the trays that come with the dehydrator and the top lid and designed some printed parts to fully repurpose the food dehydrator into a filament dehumidifer:

• A frame adapter for the flat PID controller to fit the curved wall of the dehydrator. This can be used as a cutting template (you need to cut a 45x45mm window into the dehydrator wall)
• An open cylinder that fits between the regular tray and the top lid. It is 60mm tall and you can print several. Each one can have as bottom a tray and here you are, you can dry as much as 5 spools at a time ;)

Print it in a material that can withstand the temperatures you will dry filaments! I printed mine in PETG but it deformed while drying PETG @60°C ;) It still works fine, but still…

Notes: 

1. I will not give any indication on the wiring. DO THIS ONLY IF YOU KNOW WHAT YOU ARE DOING! Double (and triple) check that you are not working inside when the device is powered! If in doubt, ask an electrician but do not risk your life!
2. the modded dehydrator now stabilizes at 50°C in less than 7 minutes, starting at 20°C. It can go past 80°C, but not wanted to push it further, because I used PETG;) As a reference, before the mod, the dehydrator maxed at around 60°C, after heating for about 1 hour.