My printer has a 450w atx power supply. My board supports a heat bed but doesnt get the stock bed hot enough(45c -.- ) so I bought a PCB heat bed to mount to the stock bed. I dont think that my board puts out enough power to get the pcb board up to temp, the manufacture said I could hook the stock bed up directly to the power supply but I'm hesitant to do so thats why I bought the PCB board.

My main question, can I simply plug the PCB board into a molex connector?

I only need it for ABS so I can unplug it for PLA and use the stock plates heat. Will it get to hot being pluged directly in? Or will it peak at a low enough temp?


This is the one I got.
[www.ebay.com]

Edited 1 time(s). Last edit at 03/16/2013 09:48PM by hendo420.

Basically you can connect it directly to the PSU, but then you have no control over the temperature. The heat bed will get hot, but how hot, you just have try. I would not recommend it. If your bed only heats up to 45 degrees, I recommend checking the wiring (12/24V). Also make sure that the heat bed is not mounted directly on top of wood or some other structure, because in that case the underlying structure will act as a powerful heat sink.

You certainly should not hook your heated bed directly to your PSU without a temperature controller.

Edited 1 time(s). Last edit at 03/17/2013 04:38PM by Dirty Steve.

What I have is a 1/4 inch aluminum plate with the same resistors that are in the hot end mounted to heatsinks on each corner. They are pluged directly into the board.

This is the board I have.
[makemendel.com]

Makemendel recomended to plug the current heated bed directly into the power supply to print ABS, again im hesitant because of having no control over the heat. Why cant the printrboard put out enough juice to make the current heated bed get to 100c. Will that printrboard make my PCB board get hot enough? If so I will just wire the PCB bed to the printrboard.

Edited 1 time(s). Last edit at 03/17/2013 06:04PM by hendo420.

You *can directly connect it to the power supply, although as has been mentioned, you won't have temperature control of the bed, so it will continue to heat until thermal equilibrium with the ambient environment is reached, until the power supply can deliver no more power to the heated bed, or until the heated bed cooks like a hotdog on a spit.

Traumflug (sp) sells an offboard switcher board suitable for use in these situations, as long as you DO have some sort of control signal available from your board for running the offboard FET, or (again, if you have a control signal available on the board) you can purchase a FET Solid State Relay that will provide similar functionality (although for most generic FET relays, you should also change the control paradigm from PID to bangbang to be safe)

Make sure to pay attention to the wiring for your heated bed. Use of under-sized conductors will rob you of power. Keep in mind that conductors for the heated bed also need to be flexible, so something like silicon coated test lead wire might be a good choice.

hendo420 Wrote:
-------------------------------------------------------
> What I have is a 1/4 inch aluminum plate with the
> same resistors that are in the hot end mounted to
> heatsinks on each corner. They are pluged directly
> into the board.
>
> This is the board I have.
> [makemendel.com]
> d
>
> Makemendel recomended to plug the current heated
> bed directly into the power supply to print ABS,
> again im hesitant because of having no control
> over the heat. Why cant the printrboard put out
> enough juice to make the current heated bed get to
> 100c. Will that printrboard make my PCB board get
> hot enough? If so I will just wire the PCB bed to
> the printrboard.

You should be able to use the Mk2 directly with the printrboard. I'm sure the wiki has wiring instructions that you can follow. As far as your aluminum heated bed with resistors, you should measure the total resistance at the leads that you to the power supply. It might be too high. You need it to be around 1.1-1.2 ohms in order to get it up to ABS temperature (110C or higher). Perhaps your aluminum heated bed was designed only for PLA.