Dec 20, 2015

110 / 230 V Mains Powered Heated Bed

12V? Nah ...
Moritz Walter wants to power his print bed from the mains power line with 110 / 230 V!


Project description:
Like many, I'm fed up with the common MK2B heated bed. It has about 1.2 Ω when wired in 12 V configuration and 4.8 when wired in 24 V configuration. Both times it outputs about 120 W of heat when driven by the appropriate voltage, resulting heatup times to print temperature of 10 to 20 minutes.
Heatup time can be reduced to 2 minutes by simply driving it with 24 V while wiring it in 12 V configuration, but well, this almost max out a seperate 500 W 24 V power supply I dedicated to driving the heated bed. Additional requirements for this setup are at least AWG 15 wire and a high current MOSFET or SSR.
The additional cost of a 500W 24 V power supply, high current SSR and heavy wire is not neglectable at all, since the can easily be half of a printers price tag. Also, bulky power supplys and wires do not contribute to the overall design and weight aspects of a 3D printer.
There are many benefits of a mains voltage heated bed: I will be driven directly from mains, skips the need for an expensive power supply and can be driven by a cheap low current SSR without heatsink. It's also cheap and provides a structural support for your printing plate, be it glass, tufnol/garolite or PEI - which silicone heater pads do not do.
Thus, a mains voltage heated bed must exist, and this project is dedicated to make it real. Additionally, this is also an attempt in making this the safest heated bed available. If you have concerns with the design, please share your ideas in the comments.

Here is his project homepage:

https://hackaday.io/project/8671-110-230-v-pcb-heated-bed

Stay safe people!