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My-Cloner Rev A — Heaters & Temperature Sensors

See Owner-Reported Hardware and Test Status for the confirmed V3.0 hardware, connections and remaining checks.

This page documents the heating and temperature-sensing architecture used by the My-Cloner Rev A.

The printer uses:

  • 1 × 24 V hotend heater
  • 1 × 24 V heated bed
  • 1 × hotend thermistor
  • 1 × heated-bed thermistor

The MKS Robin Nano V3 controls both heaters and reads both temperature sensors.

Temperature Validation Pending

The electrical input pins are known.

The hotend sensor is owner-identified as ATC Semitec 104GT-2. The original Ender 3 bed sensor is NTC 100 kΩ; its exact curve remains TBD.

The Klipper sensor_type must match the actual installed sensor.

Official References

The board-level pin mappings on this page are based on the official Makerbase schematic and the official Klipper configuration for the MKS Robin Nano V3.

The official Makerbase schematic provides separate heater outputs and thermistor inputs for the controller.

Hotend

The My-Cloner Rev A uses two heating systems:

Function Voltage Board Output MCU Pin
Hotend Heater 24 V DC HE0 PE5
Heated Bed 24 V DC H-BED PA0

The generic Klipper configuration for the MKS Robin Nano V3 uses the same MCU pins for the primary hotend heater and heated bed.

Hotend Heater

The My-Cloner Rev A uses a V6-style hotend with a 24 V heater cartridge.

Item Specification
Heater type V6-style heater cartridge
Voltage 24 V DC
Board output HE0
MCU pin PE5
Heater power 40 W — owner-reported specification
Intended hotend temperature target 300 °C — Pending validation; operating limit TBD

The heater output is controlled by the MKS Robin Nano V3 MOSFET stage.

Example Klipper structure:

[extruder]
heater_pin: PE5

Heater Power

The owner reports a 24 V, 40 W cartridge, Ø6 × 21 mm, and resistance checked against the expected 12–15 Ω range. Thermal limits and heater operation under the new configuration remain pending validation.

Hotend Thermistor

The primary hotend thermistor input on the MKS Robin Nano V3 is:

Function Board Input MCU Pin
Hotend Thermistor TH1 PC1

The generic Klipper configuration uses:

sensor_pin: PC1

The generic example configuration uses:

sensor_type: ATC Semitec 104GT-2

The owner also identifies the installed sensor as ATC Semitec 104GT-2, NTC 100 kΩ, with a reported Ø3 × 15 mm cartridge. The owner checked resistance against approximately 100 kΩ at 25 °C; exact readings were not recorded here.

Sensor Type Must Match Hardware

ATC Semitec 104GT-2 is the owner-reported hotend model. Temperature readings still require validation with the new configuration.

The final Klipper sensor_type must match the actual thermistor installed in the V6-style hotend.

Heated Bed

The My-Cloner Rev A uses a:

Ender 3 type, 235 × 235 mm, 24 V DC, 220 W heated bed

Item Specification
Bed size 235 × 235 mm
Voltage 24 V DC
Board output H-BED
MCU pin PA0
Heater power 220 W — owner-reported specification

The generic Klipper configuration uses:

[heater_bed]
heater_pin: PA0

High-Current Load

The heated bed is one of the highest-current devices in the printer.

Wiring, connectors and terminal preparation must be suitable for the final measured or specified current.

Heated Bed Thermistor

The heated bed thermistor uses the MKS Robin Nano V3 bed-temperature input:

Function Board Input MCU Pin
Heated Bed Thermistor TB PC0

The generic Klipper configuration uses:

sensor_pin: PC0

and provides the example:

sensor_type: EPCOS 100K B57560G104F

The owner confirms the original Ender 3 bed thermistor, NTC 100 kΩ. This does not identify its exact curve. The example EPCOS sensor_type must not be treated as the installed model without confirmation.

Additional Thermistor Input

The MKS Robin Nano V3 also provides an additional thermistor input:

Input MCU Pin My-Cloner Rev A
TH2 PA2 Available / currently unused

This input may remain available for future expansion.

Temperature Control

Klipper controls the hotend and bed temperatures using feedback from their respective thermistors.

The general control loop is:

graph LR
    TARGET[Target Temperature] --> CONTROL[Klipper Temperature Control]
    CONTROL -->|Power Output| HEATER[Heater]
    HEATER --> SYSTEM[Hotend / Heated Bed]
    SYSTEM -->|Temperature| SENSOR[Thermistor]
    SENSOR -->|Feedback| CONTROL

The heater is switched as required to maintain the requested temperature.

PID Control

The official generic Klipper configuration contains example PID values for the hotend and bed.

These values are not final My-Cloner values.

The final Rev A configuration should use PID values obtained from the actual machine.

Typical calibration commands include:

PID_CALIBRATE HEATER=extruder TARGET=<temperature>

and:

PID_CALIBRATE HEATER=heater_bed TARGET=<temperature>

The resulting values should only be saved after successful testing.

Do Not Copy Generic PID Values

PID values depend on the actual heater, sensor, mechanical assembly, airflow and thermal environment.

Always calibrate the physical My-Cloner Rev A.

Thermal Protection

Klipper provides thermal monitoring and heater-safety mechanisms.

The final My-Cloner Rev A firmware configuration must define appropriate limits for:

  • Minimum valid temperature
  • Maximum allowed temperature
  • Heating behaviour
  • Sensor faults
  • Heater verification

These values must match the actual hardware.

Never Disable Thermal Protection

Thermal protection is a critical safety feature.

Do not disable temperature monitoring or heater-safety mechanisms to bypass configuration or hardware faults.

Hotend Temperature Limits

The intended maximum hotend temperature for the My-Cloner Rev A is:

300 °C

The final firmware limit must only be set after confirming that all hotend components are suitable for that temperature, including:

  • Thermistor
  • Heater cartridge
  • Heater block
  • Heatbreak
  • Wiring
  • PTFE components, if present

The configured maximum temperature must not exceed the rating of the lowest-rated component.

Bed Temperature Limits

The final maximum heated-bed temperature is not yet defined in the Rev A documentation.

It must be selected according to:

  • Heated-bed specification
  • Thermistor
  • Adhesive or insulation materials
  • Magnetic sheet system
  • PEI surface
  • Wiring
  • Mechanical construction

This value will be validated during the physical Rev A bring-up process.

Wiring Considerations

Heater and thermistor wiring should be kept clearly separated where practical.

Recommended considerations include:

  • Use suitable wire gauge for heater loads
  • Use secure high-current terminations
  • Avoid mechanical strain on heater wires
  • Route thermistor wiring away from high-current cables where practical
  • Provide strain relief near moving assemblies
  • Inspect connectors for signs of overheating
  • Verify polarity where required by connected electronics

Thermistors themselves are resistive devices and generally do not require polarity, but their connection must match the intended board input.

Pre-Power Checks

Before enabling either heater:

  1. Confirm heater voltage rating.
  2. Confirm board-output assignment.
  3. Confirm thermistor connection.
  4. Verify that Klipper reports a realistic ambient temperature.
  5. Confirm that temperature readings are stable.
  6. Check that the selected sensor_type matches the installed thermistor.
  7. Verify heater wiring and connector integrity.
  8. Ensure the correct heater is associated with the correct sensor.

Never Power an Unmonitored Heater

Do not enable a heater unless its associated temperature sensor is connected, configured and reporting correctly.

First Heater Test

The first heater test should be performed conservatively.

Recommended procedure:

  1. Start with the printer at room temperature.
  2. Confirm that both sensors report approximately ambient temperature.
  3. Apply a low temperature target.
  4. Observe the correct temperature channel.
  5. Confirm that the intended heater is warming.
  6. Stop immediately if the wrong component heats.
  7. Monitor the temperature response.
  8. Confirm that heating stops when commanded.
  9. Allow the component to cool.
  10. Proceed to PID calibration only after basic operation is confirmed.

Validation Status

See Status Definitions. Design assignments and source mappings do not establish physical validation.

Item Status
Hotend heater MCU pin Source confirmed
Heated-bed MCU pin Source confirmed
Hotend thermistor MCU pin Source confirmed
Bed thermistor MCU pin Source confirmed
Hotend voltage Rev A assignment — 24 V
Heated-bed voltage Rev A assignment — 24 V
Hotend thermistor — ATC Semitec 104GT-2 Rev A assignment
Bed thermistor model Pending validation
Hotend heater power — 40 W Rev A assignment
Heated-bed power — 220 W Rev A assignment
Hotend PID Pending validation
Heated-bed PID Pending validation
Hotend thermal limits Pending validation
Heated-bed thermal limits Pending validation
Physical heater tests Pending validation