KOZOcut ESP32 Cable Cutter

KOZOcut — ESP32-C3 Cable Cutting Machine

KOZOcut is a compact cable cutting machine based on:

• ESP32-C3 Super Mini
• two NEMA17 stepper motors
• two TMC2209 stepper drivers

The device creates its own Wi-Fi access point called:

KOZOcut

Control panel address:

http://192.168.4.1

Resources

• Firmware repository:
  https://github.com/kozomeuszz/KOZOCUT
• Control panel:
  http://192.168.4.1

• Wi-Fi SSID:
  KOZOcut

   

Firmware Features

Main Functions

• automatic cable feeding to a target length (mm)
• production of a selected number of pieces
• single test cut
• manual jog feed
• steps/mm calibration
• adjustable feed and cutting speed
• configurable guillotine movement steps
• configuration stored in ESP32 memory

Required Parts

Example Parts Sources

• DRV8825/A4988 expansion board:
  https://a.aliexpress.com/_EJtjCLG
• Extruder springs 1.2 x 7.5 x 20 mm:
  https://a.aliexpress.com/_EzRrIdo
• Usongshine NEMA17 17HS4401:
  https://a.aliexpress.com/_EuOhsWE
• ESP32-C3 Super Mini:
  https://a.aliexpress.com/_EHPe6JM
• 12V / 24V power supply:
  https://a.aliexpress.com/_EuOHUfk
• MP1584EN buck converter:
  https://a.aliexpress.com/_Ez9iknU
• TMC2209 V2.0:
  https://a.aliexpress.com/_EGThV0w
• LM3UU linear bearings:
  https://pl.aliexpress.com/item/1005012350964176.html
• M3/M4 countersunk screws:
  https://a.aliexpress.com/_Ez9eS9Y
• M3/M4 rivet nuts:
  https://a.aliexpress.com/_EJ4cOce
• Adjustable UTP/STP stripping tool:
  https://a.aliexpress.com/_EG4WMGQ
• Threaded inserts for plastic:
  https://pl.aliexpress.com/item/1005007653131713.html
• M3 nuts:
  https://pl.aliexpress.com/item/1005009867140248.html

Recommended Power Setup

Recommended Configuration

• 24V DC powers the stepper drivers
• MP1584EN converts 24V → 5V
• 5V powers the ESP32
• ESP32 3.3V powers driver logic (VIO/VDD)

IMPORTANT

⚠️ Never connect 24V directly to the ESP32.

Before connecting the controller:

1. set the buck converter to exactly 5.0V
2. verify voltage using a multimeter

Driver Enable Logic

Typical TMC2209 enable pin is:

ACTIVE LOW

Meaning:

GPIO4 = LOW   -> drivers ENABLED GPIO4 = HIGH  -> drivers DISABLED

Wiring Diagram

Power Supply

The system is powered from a 12V or 24V DC power supply.

Recommended configuration:

• 24V powers both TMC2209 stepper drivers
• MP1584EN buck converter reduces voltage from 24V → 5V
• 5V powers the ESP32-C3
• ESP32 3.3V output powers the logic side (VIO/VDD) of both drivers

ESP32-C3 Connections

Feeder Driver Wiring (TMC2209)

Guillotine Driver Wiring (TMC2209)

Common Ground Requirement

All grounds MUST be connected together:

• power supply GND
• buck converter GND
• ESP32 GND
• both driver GND pins

Without common ground the system may behave unpredictably or drivers may not respond correctly.

Driver Enable Logic

EN on typical TMC2209 drivers is:

ACTIVE LOW

Meaning:

GPIO4 = LOW   → drivers ENABLED GPIO4 = HIGH  → drivers DISABLED

Common Ground Requirement

All grounds MUST be connected together:

• PSU ground
• buck converter ground
• ESP32 ground
• both driver grounds

3D Printed Parts

Recommended mechanical split:

• main frame
• feeder motor mount
• guillotine motor mount
• cable guide
• pressure mechanism
• electronics holder
• blade cover

Mechanical Notes

Before connecting motors:

✅ check smooth movement manually
✅ verify blade alignment
✅ verify bearing pressure

If mechanics bind or jam:

• motors may skip steps
• drivers may overheat
• cuts may become inaccurate

Calibration

Default firmware value:

44.0 steps/mm

Calibration Procedure

1. Feed known length

Example:

100 mm

2. Measure actual length

Example:

96.5 mm

3. Calculate new value

new_steps_per_mm = old_steps_per_mm × (target_length / measured_length)

Example:

44.0 × (100 / 96.5) = 45.60

Build & Upload

Project uses PlatformIO.

Build

pio run

Upload

pio run -t upload

Serial Monitor

pio device monitor

Default PlatformIO Port

monitor_port = /dev/cu.usbmodem1101 upload_port  = /dev/cu.usbmodem1101

If your board appears on another port:

• change the values manually
• or remove them entirely for auto-detection

First Startup Procedure

Initial Setup

1. verify wiring with motors disconnected
2. set buck converter to 5V
3. upload firmware
4. connect motors and drivers
5. enable motor power
6. connect to Wi-Fi network:

KOZOcut

1. open:

http://192.168.4.1

1. perform:
   • jog test
   • single cut test
   • steps/mm calibration

Safety Notes

⚠️ 230V AC is dangerous.

Always:

• disconnect power before wiring
• insulate terminals
• use blade covers
• never run the cutter exposed

Additional Notes

The firmware assumes every cut uses a fixed number of guillotine steps:

guillotineStepsPerCut = 1600

If blade position drifts over time:

• add a limit switch
• or implement mechanical homing

Firmware Repository

GitHub:

https://github.com/kozomeuszz/KOZOCUT

Repository contains:

• complete PlatformIO project
• ESP32-C3 firmware source
• web control panel
• motor control logic
• calibration system
• configuration storage