Creality Space Pi Automated Lid Mechanism Using NodeMCU and SG95

Creality Space Pi is a good filament dryer. However, there is one major flaw similar to some other dryers, it does not vent out the humid air, once the moisture has been extracted from the filament into the enclosed air. This traps humid air inside the dryer, making it hard if not impossible to actually dry a wet filament.

Here is a potentially over engineered solution to lift the lid of the dryer for 10 seconds every 30 mins (adjustable in the included arduino code) in order to vent out any humid air.

Parts

• NodeMCU v0.9
• SG90 servo motor
• Mounting tape
• Micro USB cable + charger block
• LED (optional)
• 220 ohm resistor (optional)

Total cost (aprox $3)

https://www.youtube.com/watch?v=OTm-7Ax17Ls

Wiring:

• Red servo wire to 5v
• Black/Brown servo wire to ground
• Yellow servo wire to D1

Optional:

• LED long leg to 220ohm resistor then to D0
• LED short leg to ground
• LED goes through hole in case and apply a hot glue from behind to hold in place

(LED will blink every 10 seconds to let you know the unit is on)

Tips:

• Solder the wires to the nodeMCU pins with the wires running up the inside of the pin so the wires run underneath the board up to the servo. There are pockets on the main body STL to allow for the added thickness of a pin with wire soldered to it.

• I have included the fusion 360 model of all the pieces assembled to give you an idea of how it should go.

Calibrate to make sure the rack and pinion are well positioned:

• Turn on the unit with no case, pinion or pusher "rack" installed.
• This will ensure the servo is at its minimum position.
• Unplug whilst in this position
• Assemble the rack and pinion so the bottom of the pusher is just shy of the end of the body.
• Slowly and carefully pull the pusher right out, being careful it only just clears the tooth of the last cog of the pinion gear.
• Assemble the case
• Slowly push the rack back in through the hole in the case, being careful you catch the same tooth of the gear you pulled it from.
• Push about half way down, plug the unit back in, and the rack and pinion should be in the correct place to not collide with the bottom of the case, or eject the pusher too far.
• Attach the unit using double sided mounting tape to the indentation on the right hand side of the space pi.
• Attach the "pusher cap" to the lid so it just clears the pusher rod when at minimum stroke.

Creality Print slicer profiles are included

• Print rack with teeth facing upwards.
• Print pinion gear flat, with raised hub upwards
• Print body flat on its back
• Case printed face down, with a small amount of support to the highest flat spot.