Food Dehydrator as Chamber Heater mod

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I wanted a chamber heater but I didn't want to spend the cost of a chamber heater. I have a food dehydrator that used to serve as my filament dryer but has long since been replaced with a SpacePi X4, so it was just sitting unused. And then, I realised, I can solve both these problems at once.

The food dehydrator I have used for this mod is an Anko brand from New Zealand KMart stores. From what I can gather, it is identical to models sold elsewhere under the "Silvercrest" and "Quigg" brands. If you're unsure, print the main piece in a cheap fast-printing material (like PLA) first to see if it fits.

The pieces that attach to the dehydrator itself, ie: "BasePlate" and "Chimney", are universal. All other pieces are specifically designed for a Flashforge AD5X with a Torreva enclosure. With a bit of creativity (or a bit of tweaking the provided FreeCAD file), you should be able to make something that suits your printer too. The FreeCAD file also includes some UNTESTED pipe pieces that may be of use for custom setups - use them at your own risk (I suspect at the very least, the tolerance on the joining part will need to be slightly reduced).

WARNING - The printed parts of this mod will be exposed to high heat. Select your materials accordingly. In particular:

• "BasePlate" and "Chimney" should be printed in at least ABS / ASA. If you are unable to print even ABS / ASA without a heater; print them initially in PETG or PCTG, then reprint in ABS or ASA while using the heater on a low setting (55 should be enough to print these materials, and safe for a PETG part for the length of time you'll need to do an ABS/ASA reprint).

• On the other hand, the mounting parts and the EVA shield / plug don't need any higher standard than the enclosure itself, so PETG / PCTG are perfectly fine for those.

• I personally used PA6-CF for BasePlate and PipeSegmentStart, and ABS for all other parts.

• Keep in mind that the dehydrator alternates between full heat and no heat, rather than keeping a constant temperature. This is why long-term use of PETG is not advised for the BasePlate and Chimney parts, even if you are using the heater at temperatures that are generally PETG-safe.

There are two variants of the "EVAGuard" piece. One has a spreader, one does not. It's up to you which you want to use - I personally use the spreader one. Installation and usage is the same regardless of which one you use.

0.6mm nozzle recommended but not required. Smooth build plate highly recommended (Glacier is close enough). The only special setting that is needed is on BasePlate; set the "Bridge Counterbore Holes" option (Quality tab) to "Sacrifical layer". The only piece that requires supports is the EVA Guard With Spreader, which requires them on the internal flat areas (at the tip) only.

Print:

• 1x BasePlate

• 1x Chimney

• 1x EVAGuard or 1x EVAGuardWithSpreader (AD5X+Torreva only)

• 1x EVAGuardPlug (AD5X+Torreva only)

• 3x UnitSupport (AD5X+Torreva only)

Before Assembly

Ensure that Chimney and EVAGuardPlug can both slide fairly easily in and out of EVAGuard (if applicable).

Assembly - Dehydrator

Remove the circular PA-GF plate in the center of the dehydrator. Break away the sacrificial bridge layer in the screw holes of BasePlate. Stick the stem of the Chimney piece through the hole in BasePlate (so that the thinner end of Chimney is protruding from the flat side of BasePlate). Use the screws from the original PA-GF plate to secure this assembly in place, taking care not to overtighten. (It may be helpful to partially tighten the screws in BasePlate before attempting to position it on the dehydrator.)

Assembly - Enclosure

Place the three UnitSupport pieces on the left, rear and right sides of your Torreva enclosure, near the middle of the span, as in the sample photos. Note the thin piece that fits into the gap between the enclosure frame and the lid.

Slide the EVAGuard piece over the Chimney piece on the dehydrator, so that the thin wide base of EVAGuard is on the side closest to the flat face of BasePlate.

Taking care to continue supporting the dehydrator's weight rather than letting Chimney push down on the EVA panel, work out where the dehydrator will sit when in use, and mark the corners of where EVAGuard will be. (As you cannot fully let the dehydrator rest unsupported at this stage, you will need to visually judge the alignment with the UnitSupport pieces. The good news is this does NOT need to be perfect, as you can just tweak the position of the UnitSupport pieces as needed later.)

Cut a square hole in the top EVA panel of your enclosure, very slightly smaller than the shaft of EVAGuard (as measured in the previous step) - you want it to be a very tight fit when EVAGuard is inserted. Once the hole is cut, insert EVAGuard into it, with the wider base on the outside of the printer.

Assembly - Putting it all together

Take the dehydrator, carefully line Chimney up with the hole in EVAGuard, and insert it. It will come to rest on the UnitSupport pieces at the sides / rear of the printer; while the front will rest on the lid's handle.

The UnitSupport pieces are not intended to be permanently attached to the enclosure or the dehydrator. They can be placed and removed as desired.

When you are not using the dehydrator-heater, I recommend taking it off the top of your printer and removing the UnitSupport pieces. This is where EVAGuardPlug comes in - to fill the hole that Chimney fits into.

How does it perform?

I have been using this for my ABS, HIPS and PA6-CF prints for some time now, and I am very happy with the results. My only criticisms relate to convenience; but I never expected it to be as convenient as a purpose-made heater.

I occasionally set it to 55° while heat soaking in order to heat up quicker, but otherwise only run it at 50° during prints. This, together with the bed at 100°, generally reaches a chamber temperature of 40° in under 10 minutes, and 50° in around 25 minutes. During printing, it seems to max out at around 58°.