Large Kossel Height issue

Hi Reprappers,

I build a fairly large Kossel ±75cm high, with a Z travel height of 37.3 mm.
When i move the hot end down 100mm, it travels 12.3mm.

I just can not find where to change this.

Hope someone can help,

Peter

Hi Peter

I assume that should read Z travel of 373mm? If Z commands are not moving the carriages the correct amount you have an incorrect steps per mm value in your firmware for X, Y and Z. The value is derived from the steps per revolution of your motor, normally 200, the microstep value you have set on your controller, normally 1/16, the number of teeth on your pulleys and the tooth pitch of your belts.

(Stepper Motor Steps x Micro Steps) / (Pulley Teeth x Belt Pitch)

So for normal steppers and GT2 belt with 20 tooth pulleys

(200 x 16) / (20 x 2) = 80 steps/mm

Andy