What a lovely design and a joy to build, Victorrr161 has done a great job.
I have changed the controls to the Arduino Nano and the stepperboard with the ULN2003A.
The main frame had two mounting studs, these were removed as the Arduino bracket is mounted using the bolts that hold the spring. Print V0038-009A_Arduino.stl for this.
The .ino file is stored in the NuMechRon_Arduino_ino_code.txt and can be copied/pasted.
The Arduino Nano and stepperboard slide into the ArduinoNano_Stepperboard_Bracket.stl and are tacked with a small drop of hot glue.
EmotionTech MicroDelta Rework
Solder the ArduinoNano to the stepperboard according to the comment in the .ino file:
// Connect pin GND of the Arduino to pin GND of the stepper board
// Connect pin 5V of the Arduino to pin VCC of the stepper board
// Connect pin A1 of the Arduino to pin IN4 of the stepper board
// Connect pin A2 of the Arduino to pin IN3 of the stepper board
// Connect pin A3 of the Arduino to pin IN2 of the stepper board
// Connect pin A4 of the Arduino to pin IN1 of the stepper board