Heated bed died, what changes do I need to make?

So, my 11A rail connection was knocked loose and arced enough that it ejected the coupling and would've started a fire if it wasn't a self extinguishing material. (Yes, I was there when it happened, no I didn't catch it in time to prevent damage)

So, repairs are off the table for several months. Printer otherwise works fine (never perfectly dialed in, but that's mostly a ~14-17C room and no enclosure) but it's been a while since I last ran without a heated bed. Running ABS on a glass bed.

I tried looking around online, but most places just talk about how the heated bed is the way to go, not how to survive when yours suddenly dies.

Also, if anyone has any thoughts on improving the safety and positive hookup of the two piece RAMPS 1.4 power connectors, I'd appreciate that as well.

Final note, system still works, even the connectors (once I cut off the bulged and blackened plastic) but the smell was awful and it was obviously beyond being put back into service. At least I can be pretty sure that's the extent of the damage.

While looking around for a solution, did you stumble across the term " external MOSFet"?
Because that's the way I would solve the problem. The onboard connector is still working and should be able to control the external MOSFet.

Another, almost no-cost-solution is to unsolder the terminal and solder wires directly to the PCB.

I was actually looking for stopgap solutions until I get it repaired, but it's far better to run it off a MOSFET than through the board. Thanks, I'll be making this modification when I repair it.

I have had mixed results using external mosfets. In particular, two failed MOSFET modules from China. I recently switched to a solid state relay module and so far that has worked well for me. I converted an old ATX power supply as the external power to my heated bed.

That's not good. Do you have any suggestions on sources or brands to use or avoid? I could always build my own, but I've never done high power PCB design, so I might end up back in the smoke-making business.

Fortunately, I have a dedicated 12v 25A commercially built supply. By the time I needed one, I was two years and two disappearing companies into building the printer, and I just wanted it done. Ironically, the last part a company took my money and ran for was a heated print bed.

The MOSFET modules I got were marked www.biqu.equipment on the pcb. I ordered 2 and one of them didn't work out of the box. The other lasted about 4 or 5 weeks and then died.

This is what I use now;

[www.auberins.com]

It is overkill for my needs but better too much than too little. That being said, you might want to throw an inline(series) fuse in the circuit on the off chance the heated bed shorts or something.

Edited 1 time(s). Last edit at 03/07/2018 02:05PM by Spiggles.