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X,Y,Z Steps Calibration Help

Posted by vennemanm 
X,Y,Z Steps Calibration Help
April 02, 2013 04:47AM
I have finished building my Prusa I3 and am working on calibrating it but I'm having issues. Here is my setup that I'm using.
Prusa I3 Single Frame
Azteeg X3 with Marlin firmware
Kysan 1124090 Steppers
GT2 Belts with 20 tooth pulley
5mm x .80 pitch threaded rods for Z axis
Repetier Host Software

Here is my problem. Steppers operate fine and in proper direction. I set the steps in the software through firmware EEPROM configuration and saved it. When I give the command to move 100mm it moves maybe half that. This is for all axis. I used the formula steps = motor_steps_per_rev * driver_microstep / belt_pitch / pulley_number_of_teeth for the X,Y axis and came up with this 200*16/2/20=80
For the Z axis I used this formula steps = motor_steps_per_rev * driver_microstep / thread_pitch and the results 200*16/.80=4000

Can anybody tell me what I'm missing.
Re: X,Y,Z Steps Calibration Help
April 02, 2013 05:03AM
Check your stepper drivers and make sure they are set for 1/16 stepping!
It looks like they are set to 1/8 stepping.

One revolution of a 1.8° stepper is 200 steps * 16 = 3200 steps/revolution.
For GT2 (2mm) belt and a 20 tooth pulley 1 revolution = 2 * 20 = 40 mm/revolution.

3200 steps/revolution * 1 revolution/40 mm = 80 steps/mm.

Since this isn't happening then something is NOT as calculated and that can only be your microstepping or that your steppers are not 1.8° steppers. The Kysan 1124090 Steppers are however 1.8° steppers so that leaves your microstepping as the culprit.

Wrong jumper, wrong switch position, bad contact...


Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse
Re: X,Y,Z Steps Calibration Help
April 02, 2013 05:43AM
rather than calculating by the pulley teeth should you not calculate by the circumference of the pulley around motor shaft? 200*16steps* 1mm/ pulley circumference should give the steps per mm.


something like that anyways.
Re: X,Y,Z Steps Calibration Help
April 02, 2013 05:52AM
Quote
jamesdanielv
rather than calculating by the pulley teeth should you not calculate by the circumference of the pulley around motor shaft? 200*16steps* 1mm/ pulley circumference should give the steps per mm.

No, (steps * microstepping) / (teeth * pitch) is EXACT and CORRECT.


Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse
Re: X,Y,Z Steps Calibration Help
April 02, 2013 10:38AM
Quote
rhmorrison
It looks like they are set to 1/8 stepping.
Surely 1/32 if they are moving half as much as they should.


[www.hydraraptor.blogspot.com]
Re: X,Y,Z Steps Calibration Help
April 02, 2013 10:53AM
Makes sense it does support 1/32 stepping. In the X3 documentation it says to install shorting jumpers on m1, m2, and m3 for 1/16 stepping, which is what I did. Anyone else using this controller that can verify that.
Re: X,Y,Z Steps Calibration Help
April 02, 2013 04:43PM
The azteeg X3 takes pololu style stepper drivers. Most of those only go down to 1/16 stepping, but those based on the drv8825 chip support 1/32 stepping. To get 1/16 stepping from that chip, you want to install only the third microstepping jumper.
Re: X,Y,Z Steps Calibration Help
April 02, 2013 04:55PM
Which I assume you mean m3?
Re: X,Y,Z Steps Calibration Help
April 02, 2013 05:07PM
Yes.
Re: X,Y,Z Steps Calibration Help
April 02, 2013 11:47PM
Quote
nophead
Surely 1/32 if they are moving half as much as they should.

eye popping smiley YES, that is of course what I meant to type... grinning smiley


Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse
Prusa i3 Microstepping
October 30, 2013 05:39AM
Hello,

which is Prusa i3 Microstepping

Is it 1/8 or 1/16 or 1/32

WIll it effect the Output Quality?

Regards,
Chandru

Edited 1 time(s). Last edit at 10/30/2013 05:40AM by gm_chandru.
Re: X,Y,Z Steps Calibration Help
October 30, 2013 06:22PM
Resurrecting zombie threads really isn't the best way to get information. Starting a new thread is a better way to go.

You want your setup to micro step at what ever it's finest resolution is. You then calculate the firmware numbers for that step resolution. If you paid the money for a 1/32 step setup, you might as well use it. The finer the resolution the smoother the acceleration. It has no noticeable impact on precision.
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