Seed Dryer 50x50mm with 5 trays for 40x20mm fans

Small seed dryer I made for a friend who grows a lot of chilis with super tiny seeds with about 1mm in diameter.

Features: 

• It contains 5 trays with the size of 45x45x10mm. 
• The trays fit tight with a 0.3mm gap into the tray holder.
• The fan is located in the bottom and presses the air through the trays to the top.
• The size of the holes can easily be adjusted by changing the infill value of the trays and the holder.

Parts used:

• Fan: I used a 40x20mm 12V Noctua fan to keep it really quiet (max. 14,9 dBA). 
• Power supply: A power supply with 12V/1.25A was used for this project which is way to strong for the small amount of power used by the fan. A smaller power supply with 12V/1A with a 5.5mm x 2.5mm barrel jack plug will be good enough too.
• Power jack: The shown power jack is screwed into the 12mm hole in the base to power the fan.

Wiring: 

The +12V needs to be connected to the yellow wire of the fan and the GND connection goes to the black wire of the fan. That should be an easy soldering job for these 2 connections. I screwed it first in place and then soldered the 2 wires in the fan base.

Printing instructions:

If you don’t want to use my GCode files for the Pruss MK3S+ then you need to adjust the print settings for the tray holder (part “Holder”) and the 5 trays (part ”Tray”) to the following settings:

• Profile and resolution = 0.2 speed profile with these additional settings:
• Contour lines = 7
• Top layers = 0
• Bottom layer = 0
• Infill = 60% (can be adjusted for the diameter value of the holes)
• Brim = on with 5mm
• The part "Holder“ need supports set to „overall“ turned on. 

The lower part (name “Fan”) that contains the fan and power jack can be printed with normal settings in 0.2 speed profile resulution. I just set the brim to on and to 5mm to avoid warping here too.

Final step:

The tray tower is pressed into the base when the fan and the power jack was inserted and tested before. It press fits well to avoid the usage of glue which you don’t want to use in a project like this I think.

Notes: 

• The trays should not be opened when the fan is turned on. ;)
• There is also a bigger version for 80mm fans available: Seed Dryer 85x85mm with 3 trays for 80x25mm fans

Happy printing :)