This build uses cheap standard components; design was done from scratch with two main targets:
- robust operation => 3mm wall thickness
- easy, fast printing => small overall size, minimum support requirements
- Arduino nano 168, 5V
- 9g standard tower servo
- 10k resistor
- on / off switch, 3A 125V, 5x8 housing
- USB cable
- some super glue to mount printed arm to servo arm
- 4 nuts M3
- 2x M3x12 used as a hinge for the lid
- 2x M3x16 to close the box
- optional: 1000yF electrolytic capacitor (when servo moves fast, Arduino might crash without it due to high peak current requirements; in case needed, just add it in parallel to Servo power cables)
- about 50g of filament at 25% infill
Before you ask:
Schematic and Arduino code were taken from here; no need to reinvent the wheel;-)
The box will take everything inside; takes some patience, but it works!
Power is brought to the circuit by a USB cable. I cut it off an old mouse and soldered it directly to Vin of the Arduino.
Print time in total is a little less than 4 hours on my Anet A8; only the cover will need a little support when printing for the recess of the lid.
Tolerances are easily meet; I assembled mine right off the printer - no grinding or drilling.
Supports only needed for cover; touching build plate is sufficient