- Stock: 36
- Model: Mk3-220x220-12/24v
Model:
MK2B 12V / 24V
MK3 12V / 24V
MK3 220x220 12V / 24V
MK3 220x220 12V + Wires
ALU 220x280 12V
MK3 235x235 24V
MK3 235x235 24V + Wires
ALU 329x329 24V
MK3 400x400 24V
MK3 500x500 24V
220 × 220mm MK3 ALU heated bed with a 3mm aluminium core and a heater circuit selectable for 12 or 24V DC. The bare metal face provides a rigid surface while the black underside carries the heater circuit, thermal warnings and connection pads.
Four countersunk mounting holes allow screw heads to sit flush. It is supplied without wiring or thermistor, making it suitable for custom installations where the sensor, connectors and wire size can be selected for the machine.
Main specifications
| Dimensions | 220 × 220mm |
|---|---|
| Nominal thickness | 3mm |
| Supply | 12 or 24V DC, according to the pads used |
| Circuit | One 35µm copper layer |
| Mounting | Four countersunk holes |
| Declared maximum temperature | 180°C; not a recommended setpoint |
| Contents | 1 bed; thermistor, wires, connectors and magnetic surface not included |
12 or 24V connection
- 12V: pad 1 to positive, pads 2 and 3 to negative.
- 24V: pad 2 to positive and pad 3 to negative; pad 1 remains unconnected.
Never apply 24V to the 12V connection. Check the table printed on the supplied unit and measure the selected cold circuit before soldering.
Power and sizing
This revision does not have a declared power rating. Measure its cold resistance—subtracting the meter-lead resistance—then calculate current with I = V / R and power with P = V² / R. Use the results to size the supply, fuse, wiring and power stage.
The controller output must support continuous current with margin across its MOSFET, PCB and terminals. If this is not documented, a 12/24V external MOSFET module may be used after checking its actual capacity, cooling and terminals.
Sensor and firmware
Secure the sensor near the thermal centre so it cannot detach during movement. A 100K Beta 3950 NTC thermistor with Dupont connector may be used when the input, connector and firmware configuration match.
- Marlin: type 11 is commonly used for a 100K B3950 NTC with a 4.7kΩ pull-up; verify the board. Bed PID can be tuned with
M303 E-1 C8 S60. - Klipper: use
sensor_type: Generic 3950, thenPID_CALIBRATE HEATER=heater_bed TARGET=60andSAVE_CONFIG. - RepRapFirmware: declare the actual NTC, Beta and pull-up; heater 0 can be tuned with
M303 H0 S60and checked usingM307 H0.
60°C is only an example. Keep failed-heating and thermal-runaway protection enabled, and perform the first low-temperature test under continuous supervision with an independent temperature reference.
Installation and build surface
Install the aluminium face towards the build surface and the black heater side underneath. The countersinks allow screw heads to sit flush, but the plate must not be distorted by overtightening. Add strain relief so Y-axis movement cannot flex the solder joints.
A lower thermal insulator can reduce heat loss, provided no metallised face touches tracks, pads or the sensor. The bed is not magnetic by itself: the 220 × 220mm smooth/textured PEI sheet requires a compatible magnetic base with a suitable temperature rating.
Compatibility
Suitable for RepRap, Prusa i3 derivatives, P3Steel, 3DSteel, Anet A8 and custom projects only when external dimensions, mounting pattern, travel, voltage, calculated power and wire exit all match. An Ender-3 normally uses a 235 × 235mm physical platform, so this bed is not a direct replacement merely because its nominal print area is close to 220 × 220mm.
For the same nominal size with wiring and sensor already installed, see the 12V, pre-wired 220 × 220mm MK3 ALU heated bed.









