Generation 7 v1.4 Heated Bed temperature

Hey guys,

I have a problem with my heated bed using Gen7 1.4 electronics.

The temperature of my heated bed only rises to about 60°C even when I tell the board to heat it to 110°C (M140 S110, followed by M116)
My heated bed mosfet is, as suggested in the outdated version 1.4, the same as the extruder heater mosfet (MOSFET IRFZ 44N).
I use Teacup Firmware as suggested by Traumflug.
My PSU has 300W; 10A at 12V.

In addition to that my heated bed temperature rises really slowly. Shall I replace the "old" 1.4 mosfet (mosfet temperature is ok) to solve the issues?

(By the way: Thank you Traumflug for Gen7!)

Thanks a lot!

Christian

Edited 3 time(s). Last edit at 03/09/2013 10:28AM by rapidelectron.

Depends on your heatbed resistance, usually 1.2 Ohm, you need at least 10A in the 12V output of your PSU:

A = V/R = 12/1.2 = 10A

only for the heatbed.

Hotend and motors also need to be supplied with this same amperage, so regarding your stepper calibration (200mA per motor) and your hotend resistor (5.6 to 6.8Ohm, so 1.7 to 2A), you need 3A plus the 10A for the heatbed.

There are maybe another reasons, but I belive that this may be the first you need to check.

My heated bed resistance is 1.5 Ohm. Using another PSU (330W; 12V 16A) improves heat up times and max temperature (It now reaches 110°C)

Thanks xoan!