stepper settings/ calculation set up

Hello,
On z axis I used the pncconf wizard,and I typed in my values, tested the axis with in the wizard and in linuxcnc and it worked. I move 3 inches in software, torch physically moves 3 inches,GREAT.
Tried the same for the other axis, and when I used the calibration wizard I get no movement , 99.999991 % user input error. with the following ini for joint 0(x) , see below, I get movement, although when I jog axis +48 inches, I physically get about 42 inches of travel. I've read the docs and watched some you tube videos on the concept. Now I need guidance here
what I have for my x axis
200 Steps Per Rev.
driver setting is (1/ 1600-> 200*1600 = 3200
I have the 22 tooth pulley attached to my stepper motor and it has a 20 degree pitch. i take 22*.2 = 4.40 than I take 3200/4.40 = 727.272727
but that does not look right. or I'm missing something?

My hardware
Standard Rack and Pinion Drive, NEMA 23 www.cncrouterparts.com/standard-rack-and...ve-nema-23-p-50.html
570 oz stepper motors www.automationtechnologiesinc.com/produc...23h2100-50-4b-cable/
KL Stepper 5046 drivers www.automationtechnologiesinc.com/wp-con...2012/05/KL-50421.pdf



from my ini file
[JOINT_0]
TYPE = LINEAR
HOME = 0.0
FERROR = 0.5
MIN_FERROR = 0.05
MAX_VELOCITY = 7.16666666667
MAX_ACCELERATION = 50.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 8.96
STEPGEN_MAXACCEL = 62.50
P = 1000.0
I = 0.0
D = 0.0
FF0 = 0.0
FF1 = 1.0
FF2 = 0.0
BIAS = 0.0
DEADBAND = 0.0
MAX_OUTPUT = 0.0
# these are in nanoseconds
DIRSETUP = 10000
DIRHOLD = 10000
STEPLEN = 5000
STEPSPACE = 5000
STEP_SCALE = 1600.0
MIN_LIMIT = -0.001
MAX_LIMIT = 48.5
HOME_OFFSET = 0.0
#******************************************

motal2004 wrote: what I have for my x axis
200 Steps Per Rev.
driver setting is (1/ 1600-> 200*1600 = 3200 <<<<<
I have the 22 tooth pulley attached to my stepper motor and it has a 20 degree pitch. i take 22*.2 = 4.40 than I take 3200/4.40 = 727.272727
but that does not look right. or I'm missing something?

Hmmm no, 1/8 is as simple as 1600 written on the side of drive box, It means that for 1 step of the motor movement it will need 8 steps to the input. So for 200 steps of the motor it needs 1600 steps on the input.
I have no clue about the pulley, you would have to provide a distance traveled for one full rotation of the pulley, so grab a measuring tape and mark the strat point on the rack and pinion then rotate the pinion one full turn and mark the rack where the pinion mark is, measure between marks on the rack.

my mistake tommylight i had the number 3200 stuck in my head. it should have been
200 rev * 8 micro step which gives 1600 steps and that is on the side of the driver. I will take measurements later today

No problem at all, you are welcomed to ask anything.

Racks (non metric ones at least) are usually specified in diametrical pitch, This means that a 20 pitch pinion of 1 inch diameter would have 20 teeth and the matching rack would have 20 teeth cover pi inches (about 3.14 inches). So one rev of your 22 tooth pinion should travel 22(pi)/20 inches.

I have Module2 rack and pinion with 20 tooth, it does 12.5CM per rotation, or about 5".

go it figured out. it helps writing out all the steps of the calculations.
Thanks again guys for all the help.

Nice.
You are welcomed.

Todd Zuercher wrote: Racks (non metric ones at least) are usually specified in diametrical pitch, This means that a 20 pitch pinion of 1 inch diameter would have 20 teeth and the matching rack would have 20 teeth cover pi inches (about 3.14 inches). So one rev of your 22 tooth pinion should travel 22(pi)/20 inches.

You guys really do it the hard way. In all the other contries in the world (minus one other obscure one) metric makes it so much easier

Take Tommy's module 2, 20 tooth pinon,

The diameter is 2 * 20 = 40mm
The Circumference (distance travelled) is 40mm * pi = 125.66mm

The silly bit is that the world agreed to use the same methods for invloute gears back in WW2 (or was it WW1) but the insistance to quote TPI just makes it harder for you guys.

rodw wrote:

Todd Zuercher wrote: Racks (non metric ones at least) are usually specified in diametrical pitch, This means that a 20 pitch pinion of 1 inch diameter would have 20 teeth and the matching rack would have 20 teeth cover pi inches (about 3.14 inches). So one rev of your 22 tooth pinion should travel 22(pi)/20 inches.

You guys really do it the hard way. In all the other contries in the world (minus one other obscure one) metric makes it so much easier

Take Tommy's module 2, 20 tooth pinon,

The circumference is 2 * 20 = 40mm
The diameter (distance travelled) is 40mm * pi = 125.66mm

The silly bit is that the world agreed to use the same methods for invloute gears back in WW2 (or was it WW1) but the insistance to quote TPI just makes it harder for you guys.

The only difference is inversion, the calculations are almost the same, other than the units difference.

PS: 40mm would be the diameter, 125.66 would be the circumference.