Geeetech

Hi,

I have the 3-in-1 control box. With the power supply outputting 12 volts, I measure 11.5 volts across the heatbed terminals when it is on. Can I turn up the voltage from the power supply a little? Say to 13 volts?

The reason is that my heatbed temp seems a little low.

The GT2560 documentation says input can be 12-24v, so I think this should be OK, but thought I would check first.

Thanks

You might need to check the heatbed resistance first, if it's too big then it won't reach the temperature. Check out this link to measure it:
http://www.geeetech.com/forum/viewtopic ... 19&t=17039

Hi Mark,

The heatbed measures 1.4 ohms across the red wires, cold.

When set to 115C in Repetier (as measured by the built-in thermistor), the aluminum bed itself only goes to 75C, as measured with a thermocouple. That's as hot as it goes, ie setting Repetier to 117C results in no additional heating.

I figure there's some drop across MOSFET, maybe I can increase voltage from power supply to get heatbed voltage up to 12volts.

You can try to increase it to about 13V, but not too high or it might damage the board or PSU.