# configuration before printing

Hi dears

i'm try to make my own 3d printer.before complete the project and testing,i think i must config my step motors by changing step_units,when i calculate step per unit(mm) i reach this number (19.6850) but this number dos not config my stepper motor correctly,but when i product this number to 10(19.6850*10=196.85) and add to configuration all of things are ok and machine works correctly.

my question is that,why the number must product to 10 in full step controlls?

• How do you come to 19.6850? Maybe there is an error that factor 10 corrects. 20 steps per mm is very low resultion and totally unusual.
• based on this tutorial:

`StepsPerTurn = 400 // Most stepper motors have 0.9 Degree per stepBeltDistance = 2.032mm // Distance between repeating grooves. GT2 belt = 2.032mmGroovesInPulley = 10 // 8-10 are common values---> FOR ME IS 10Substepping = 1//for a full step neededStepsPerMM = StepsPerTurn*Substepping/(BeltDistance**GroovesInPulley)           = 400*1/(2.032*10) = 19.6850`
• With full steps 20 sounds mathematically reasonable. I have 160 steps on my X with 1/16 microstepping.

I would look into microstepping if I were you. What stepper drivers are you using?
based on this tutorial:

`StepsPerTurn = 400 // Most stepper motors have 0.9 Degree per stepBeltDistance = 2.032mm // Distance between repeating grooves. GT2 belt = 2.032mmGroovesInPulley = 10 // 8-10 are common values---> FOR ME IS 10Substepping = 1//for a full step neededStepsPerMM = StepsPerTurn*Substepping/(BeltDistance**GroovesInPulley)           = 400*1/(2.032*10) = 19.6850`

• drv 8825