Smoothieware extruder.hotend.steps_per_mm, how to calibrate for E3D V6

Hello, I am pretty new to smoothieware, I did not find a search function on the forum, if there is, please enlighten me and sorry, if my questions have been asked before.
A while ago I was able to buy a used smoothieboard version 1.1 for my current project, which is a D-BOT CoreXY printer (I have a working Anet A8 with Marlin/Skynet though). I just finished the build of the printer, everything is working so far, but I have problems to determin the correct feedrate of filament to my E3D V6 hotend, since I just dont know, what value to use for the “extruder.hotend.steps_per_mm”. No matter what I put in this value, it always seems to be too much, filament gets stuck in the hotend from time to time. So does anyone know, how to correctly calculate the steps_per_mm value on combination with the diameter of the extruder gear? Or is that even the right value to calibrate. Any help would be appreciated.
Thanks in advance.
Here is the relevant part of my config file:

+ show block

[[code]] extruder.hotend.enable true # Whether to activate the extruder module at all. All configuration is ignored if false
extruder.hotend.steps_per_mm 570 # Steps per mm for extruder stepper
extruder.hotend.default_feed_rate 2700 # Default rate ( mm/minute ) for moves where only the extruder moves
extruder.hotend.acceleration 1000 # Acceleration for the stepper motor, as of 0.6, arbitrary ratio
extruder.hotend.max_speed 45 # mm/s

extruder.hotend.step_pin 2.3 # Pin for extruder step signal
extruder.hotend.dir_pin 0.22! # Pin for extruder dir signal
extruder.hotend.en_pin 0.21 # Pin for extruder enable signal
[[/code]]

Imported from wikidot

For the Extruder.

The only thing you will need to update is your steps per mm. For a standard 200 step motor with 16x micro-stepping you will need:
#define DEFAULT_AXIS_STEPS_PER_UNIT {_,_,___,456} ;

For a more in-depth explanation, see the Titan documentation.

Also useful : http://www.prusaprinters.org/calculator/

But often the theoretical value is not right, and you just need to lower it until it is right.