Extrusion problem, need help

Hi Sir,
Have just assembled a Kossel Mini.
Everythings well during the build up and begun doing a calibration spiral for a test print.
The first extrusion circle is ok but on the second circle its not extruding filament out of the nozzle.
Extrusion motor making knocking noise.
I tried to push the filament by hand and it extrude filament out of the nozzle and its ok.
I have attached 2 photos.
Did several bed leveling and still the same problem.

New to this hobby and need help.

Thanks

Levelling has nothing to do with the basic setup of the motors
Either your filament has trouble being pushed through or the motor current on the driver board is set too low - which I suspect.
So carefully adjust the potentiometer for the extruder motor until the knocking is gone - check the temp for the motor while printing to make sure you did not go too high and it overheats.

Many thanks, can you let me know where I can adjust the potentiometer of the extruder?
Is it in the display or in the board?
I'm running Anduino 2560 + Ramps 1.4 with LCD display and Repetier Host.

Have found where it is and solved the problem.
Really appreciate your help Downunder35m.
Hope you can help more people like me
Cheers

Glad you got it sorted, enjoy printing in 3D!

how did you fix it
mine is doing the same

As said above: Set the motor current for the extruder properly - check your manual for this as I am not clairvoyant and have no idea what printer or electronics you use

I adjusted the potentiometer like Downunder35m has said.
There is a small screw to adjust it.
I have attached a photo.
Mine solved the problem and hope this help