Third Thumb

This is a recreation of Dani Clode's Third Thumb project. I've been working on this for approximately 2 years.

Here's a BOM:

• PLA (or any other rigid filament)
• TPU (or any other flexible filament)
• PTFE tube (ID=1mm, OD=2mm)
• Fishing line
• Arduino Nano
• Nano servo expansion board
• SG90 Servo
• Jumper wires
• Rubber bands
• Pressure film resistor (I used tis one)
• 10 kOm resistor
• Unnecessary: 6x AAA batteries
• Unnecessary: 12x M3x10 screws
• Unnecessary: 12x M3 Nuts

Printable parts:

• TTTP_Finger
• TTTP_Mount
• TTTP_MountSupport1
• TTTP_MountSupport2
• TTTP_BoardBox
• TTTP_BionicMuscle
• Unnecessary: TTTP_BionicMuscle_BeltLoop_1
• Unnecessary: TTTP_BionicMuscle_BeltLoop_2
• Unnecessary: TTTP_BoardBoxLid
• Unnecessary: TTTP_BeltBatteryPack (remixed from this)

Parts marked “Unnecessary” make the project portable.

Being space efficient was never the point, the project is made for one 5 minute presentation, however i am going to be releasing it for download soon. It would be nice to make it actually usable, practical and modular. So if you have any suggestions or pictures of technical details DM me. Thanks in advance!

Here's my reddit post where you can ask any questions about the project.

Sadly, there are no instructions for assembly, because I've been working on this for ~2 years and I'm sick of it :) There is the code:

#include <Servo.h>

Servo myservo; // create a servo object to control the servo motor

int potpin = A0; // analog pin a0 for the resistive sensor

int val; // variable to read the sensor value

void setup() {

myservo.attach(9); // connect the servo motor to pin 9 of the servo object

Serial.begin(115200); // connect to the serial monitor with baud rate of 115200

}

void loop() {

val = analogRead(potpin); // read the sensor value (value between 0 and 1023)

Serial.println(val); // send the sensor data to the monitor (for debugging purposes only)

val = map(val, 500, 20, 0, 180); // convert the amplitude of the value to degrees (value between 0 and 180)

myservo.write(val); // send the command with the variable to the motor

delay(15); // wait for 15 milliseconds

}