Converting the 12VDC M2 bed heater to work with 24VDC

[Tshulthise]

If you buy the 12 to 24V conversion from MakerGear don't throw your old heated bed away. The original 12VDC heated bed can be converted to work with a 24VDC power supply using the following guide.

1. Pull the rubber heater off by pulling on one corner. The adhesive sticks to the heater. Be careful to not get any dirt, lint or dust on the adhesive side of the heater.
Note: It sticks back to the aluminum build plate very well even though neither surface feels very sticky
2. Cut the copper trace as shown in the photo using an exacto knife. Be careful to not cut all the way through the rubber.
3. Cut the connector off about an inch from the connector
4. Check the resistance between wires 3 and 4. It should be between 3 and 4 ohms.
5. Cut wires 1 and 2 short and put some heat shrink over them to keep them from shorting onto metal surfaces.
6. Make sure the aluminum heat spreader is completely clean. I.E. Make sure there is no oil from your fingers. Cleaning it with Acetone is recommended.
7. Carefully align the heater on the aluminum plate and push in the center and work your way out being careful to not trap any air

The heater is now compatible with 24VDC. Since its not the same resistance as the new MG 24VDC heated bed.

I'm pretty sure the MG comes set to control the bed using an "on-off" algorithm. If you have your firmware set to control the heated bed using PID then you will need to run the auto-tuning routine http://reprap.org/wiki/PID_Tuning.

[thecadman99]

Awesome! Thanks

So... will running at a higher ohms rating (say 2) kill the power supply? That should cause the bed to heat faster correct?

[Tshulthise]

I = V/R so higher ohms means lower current means slower heating. You have to make sure that your power supply can handle whatever resistance you connect it to.