Help on calibration

[Hobbit]

Hello all,
i am new here and to 3d printing!
my neighbor built a cnc that worked for the last 5 years.
we decided to buy everything needed to convert it into a 3d printer.
so removed the nozzle, and placed the extruder and a heat bed.
we programmed a arduino to read both temperatures and heat the extruder and heated bed.
everything works... calibration time.
in mach3, the axes x y and z are calibrated.
if we ask to move 15mm, it moves 15mm.

but how do we calibrate the speed of the motor who sends the pla ?
is there any guide ?

maybe a guidline ?
lets say my x is calibrated to 670, y to 340 and z to 560 ( not real numbers here... just thinking ). Is there a number to start with to calibrate the extruder and then we do trial and error ?

as i said, i am really new to this and i am trying to help my neighbor...i know he will never ask for help!!

thank you very much,
Martin L.

[jjpython]

You need to know how many steps the extruder rotates to how much the filament moves, ie it moves the filament 100mm and rotates 305 steps, im not overly good at describing but i hope that helps

[Hobbit]

You mean that it is the same thing as the other axes ?
on x, if i ask for 10mm, it move 10mm
on the extruder, if i ask for 10mm , 10mm of pla should come out ?

[jjpython]

Yes, usually measured over 100mm for better accuracy, i think mine is somethi g like 84.75 steps per 100mm

[Hobbit]

Ok thanks a will test it and giveit a try.
i already have a lot of project