Normally ramps wont run the extruder if the thermistor for the hot end isnt at full temperature.
So you will need to disable minimum temperature or set it below ambient temperatue in the firmware.
What your looking for is called something else. Its often referred to as jogging or moving the axis.
The extruder is treated as just another axis in the firmware.
Not sure on your particular lcd but it should use simalar names in the navigation.
To find the extrude function in my full graphics lcd controller.
Look under prepare - move axis - select increment - extrude.
Extrude isnt under all of the increment values.
Its easier to use the pc to move the axis for calibration as you can select the distance then tell it to move.
But the smart controller will start moving as soon as you adjust the value.
The software like repetier gives you better control for calibration.
Gordon
Edited 1 time(s). Last edit at 03/01/2015 07:21AM by gordonendersby.