A fully assembled and tested Dankdryer suitable for
use with Type B power outlets (as found in the US, Canada, Mexico, and
Japan). Visible components will be printed using black carbon
fiber-infused nylon and green TPU 95A. Internal components will be printed
using polycarbonate. All filaments used will be capable of sustained operation at 150℃.
Exact filament may change from unit to unit.
The electrical components of a Dankdryer. You print
and assemble the rest. Printing will require approximately 600g of
filament using recommended settings. Assembly does not require soldering,
and ought take approximately half an hour.
For the assembled dryer, simply lift the top, and remove the packing
material inside the upper chamber. There is no packing material in the
lower chamber. Once the packing material is removed, put the top back
on the upper chamber. If you're assembling the dryer, see the
instructions below.
Plug the supplied power cord into the side of the dryer, and into a
120V AC outlet. Turn the dryer on using the switch on the side of the lower
chamber. If power is flowing, it will light up. Both fans ought also
start spinning.
Bluetooth Low Energy GATT is used to configure networking. The device
will appear as a BLE peripheral having the name "dankdryer" followed by
some string. Connect, and write to the ESSID and PSK characteristics.
Once they've been populated, the dryer will begin attempting to associate
with the specified WiFi network (note: only 2.4GHz channels are supported).
Once it successfully associates, these parameters are locked in, and
can only be changed following a factory reset.
Reporting
Upon pulling a DHCP lease, the dryer will serve HTTP on port 80, and
will publish to an MQTT broker. The same information is available
via both interfaces:
Uptime in seconds
Temperature of the controller in degrees Celsius
Temperature of the upper chamber in degrees Celsius
Measured weight (tared) in grams
Tare base in grams
Upper (exhaust) fan speed in rotations per minute
Lower (intake) fan speed in rotations per minute
Upper fan duty cycle [0..255]
Lower fan duty cycle [0..255]
(*) Spool speed in rotations per minute
(*) Target temperature in degrees Celsius
(*) Heater status (on/off)
(*) Motor status (on/off)
(*) Time remaining in dry in seconds
Items marked with an asterisk are only expected to be non-zero during
active drying. The heater will not necessarily run constantly during
drying. The spool ought rotate at about 5 RPM when the motor is on.
Taring
Taring calibrates the scale's zero point. Taring ought be performed without
a spool (or anything else) sitting on the platform, but with the motor, the
motor coupling, and the platform all installed. Simply press the Tare Scale
button on the web page, or post to the /tare MQTT topic. Taring
is instantaneous.
Drying
Remove the top and place a spool of filament into the upper chamber,
atop the spool platform. The spool ought sit level. Replace the top.
Without the top in place, drying will be less effective and consume
more power. Note that generic spools will melt under high temperatures;
if drying at 80℃ or more, be sure to use a high-temperature spool.
Drying can be initiated via the HTTP server, or via MQTT. It is necessary
to specify the target temperature (in degrees Celsius) and the length of
the dry (in seconds).
When drying is complete, remove the top and extract the spool. The
spool might be hot.
Updating firmware
Firmware can only be updated through the web page. Firmware updates are
expected to be a very rare event. Press Select Firmware, and choose the
file using the provided dialog. Press Upload Firmware. The update
process ought take less than a minute.
Factory reset
Post to the /factoryreset MQTT topic, or click the Factory Reset
button on the web page. This will reset networking options and tare
settings, and cancel any ongoing drying activity.
Components/assembly
Not necessary if you purchase an assembled Dankdryer!
Seven (or possibly eight) objects are printed using four generated STL
files. They ought be printed in the generated orientations.
Internal components (load cell coupling, motor coupling, spool platform, AC shield)
Optional interlayer (print using suitable TPU 95A!)
The OpenSCAD files can be found on Github.
The zipped STLs can be found here,
and a 3MF is also available.
I print them with the Arachne perimeter generator and infill combination
using cross hatch for the sparse infill. Using Polymaker Fiberon PA6-CF20
(nylon-6 + carbon fiber) with these settings, the chambers and top require
about 600g. I typically use Bambu Clear Black PC (polycarbonate) for the
internal components, and Overture TPU 95A for the interlayer.
The interlayer is only necessary if your hot and cold chambers don't mate
properly, which shouldn't happen so long as you print them with the same
materials, using the same settings.
Warp-free printing is essential. Warping of the internal components or
the lower chamber can result in the spool not sitting level. Warping
of the upper chamber can result in it failing to mate to the lower
chamber.
Push the 175℃ thermostat through the bottom of the upper chamber.
Push the LM35 through-hole thermostat through the three small holes
in the floor of the upper chamber.
Use four M4 screws to mount the ceramic heating element to the floor
of the upper chamber.
Use four M5 screws to mount one of the 80mm fans to the outside of
the upper chamber. The logo ought be facing out; this fan is an exhaust.
Insert the power plug/rocker switch unit into the rectangular
hole on the side of the lower chamber. It ought not move once
inserted. Secure it with hot glue.
Use two M5 screws to mount the AC adapter to the floor of the lower chamber,
on the side opposite the intake fan.
Wire the plug/switch to the AC adapter.
Place the AC shield atop the AC wiring, and push it down. Secure it
with hot glue.
Use four M5 screws to mount the PCB to the floor of the lower chamber,
next to the intake fan.
Insert the antenna into the antenna hole to the left of the lower chamber's
fan. Secure it with hot glue.
Connect the antenna to the U.FL connector on the PCB.
Use four M5 screws to mount the other 80mm fan to the outside of
the lower chamber. The logo ought be facing in; this fan is an intake.
Connect the lower fan to the fan connector marked "lower" on the PCB.
Connect the upper fan to the fan connector marked "upper" on the PCB.
Use two M5 screws to mount the load cell to the central riser in the
lower chamber.
Insert the motor into the motor coupling, ensuring the positive terminal
mates to the hole marked '+'. The terminals ought go through the holes.
Wire the motor to the PCB.
Wire the heating element to the 175℃ thermostat.
Wire the heating element to the PCB.
Wire the 175℃ thermostat to the PCB.
Optional: place the interlayer atop the lower chamber.
Place the upper chamber atop the bottom chamber/interlayer, matching the four holes.
Use four M5x35 bolts to securely mate the two chambers.
Push the spool platform down around the motor coupling.
Push the motor coupling down around the rotor and the top of the motor.
The platform ought provide a level surface.
