Adding a heated build plate?

I’d like to add a heated build plate to the Mbot Grid II. I see on the circuit board there’s output for the heating element what I’d like to know is what voltage output is. There is a thermistor plug on the circuit board but it uses a 4 pin mini plug instead of terminal screws like the extruder uses. Which two of the four pins would be used for the thermistor connection ?


here is some information about the heat bed

the out put on the motherboard is 24V

Thanks for info for the output voltage. The diagram of the thermistor plug makes no sense at all. I’m guessing you have a thermistor with a 4 pin plug available and if so what would the cost be. If that’s not the case what pins on that 4 pin plug would I use for a 2 wire thermistor.

The Heat output on the board is 24 volt but the power supply in not enough to power a 200 watt heater
You will need an external power supply with 250 watt at 24 volt and use a relay to power up the heated bed

This is the schematic you will follow
I did the same thing and works perfect with ¼” thick glass
You also have to enable the HBP from printer’s settings and change the START and END GCODE for your printer to include the HBP and set temperature
To enable the HBP go to the printer menu under utilities under general settings scroll down until you see the option HBP installed is set to NO turn it to YES exit the menu and reset printer from the reset button
If you do that before install the thermistor you will have the following error on the printer
Platform failure! Temperature reads are failing! Check wiring!

MakerBot MightyBoard rev.E HBP thermistor connection schematic:

If you use an external resistor 4k7 it is necessary to unsolder the resistor R65. Or it is better to replace the resistor R65 100k -> 4k7. Otherwise there will be an error of temperature measurement.
Simply (instead of two power supply units) replace the power supply with new more powerful (I bought 24V 400W) and the relay is not needed. But I have an old board rev.A, so the situation is more complicated. So I need to get 5V from 24V using an external DC/DC converter. I’m doing it, but still did not finish.

I came across this external HBP for 3D printer and it seems to be the easiest route to add HBP to Mbot for non-technician user. But it is not a cheap method though.

This is good news , I’ll start arranging to add a HB to my grid2
What are the changes needed for START and END GCODE , and if I install a flat bed with out the calibration grooves , how to I avoid the initial alignment routine?


hi mkcreta,

can you share a pic of the final heatbead, and the heat element you used .

how did you manage the calibration cutouts ? did you cut a costume glass top ?


this is my bed i will post picture when i will return to new York

Hi friends
I have added mk2b heated bed and i have two problem.
1)I connect the heated bed to the front of normal bed and i have change the z endstop height, after finished the printer, it try to move down too much…
2) how i enable heated bed when printing?
Thank you