[xakep4eto]

i am building a new machine and getting really confuse about stepp per unit.Just got my electronix working ad was truing to set the step per unit but looks like i am making mistake some where so please help.
This is my configuration:
smoothstepper , pmdx126, 4x gecko g203v(which is 10 microstep) and 4 nema34 640OZ
i am using sfu2010 which mean that this ballscrew has 10mm pitch so one revolution will move the axis 10mm is that right ?
so when i do the calculation i am getting that step per unit have to be set on 200 but when i have it set on 200 one rpm will move the axis 40mm.
so i fig out that the right step per unit in my case are 800 which move the axis exactly 10mm ,but i was wondering what is the actual formyla to calculate this
Thanks in advice

[jalessi]

xakep4eto

See attached link for steps per calculator.

Leadscrew driven calculator is in the middle of the page.

RepRap Calculator3

http://www.machsupport.com/forum/ind...0;attach=23771



Jeff...

[xakep4eto]

thanks i have this calculator but still make no sence to me why the calculator show 200 ????

[cgo]

If the stepper motor is 200 steps per 360 degrees (most are) 1.8 degree per step then.

Motor steps x microsteps per step = steps per rotation, so if you input what you said you are using, it is ( 200x10=2000 steps) = 360 degree of rotation

You may want to check your driver microstep settings (200 x 1/4) = 800

Stepper Motor Calculations - A Quick CNC Wiki


Use cm for inches in the first example in this link (10mm pitch = 1 turn per cm)

[xakep4eto]

thanks for the replay.
I have Gecko G203V which is only 10 micro-steps, the motors are KL34H280-45-8A which are 1.8 degree per step.and the ball screw is SFU2010 which is 10mm pitch, so from mu understanding one revolution on the ballscrew will move the axis 10mm and at the same time the motor have to make also one revolution because the motor and the screw are connected directly to each other.

so when i set the step per unit on 200 and do one rpm with the motor on mack the shows that the axis move 40mm
when i change it to 800 one rpm on the motors shows 10mm on mach 3 which mean is gonna rotate the ballscrew 1 rpm also and move it 10 mm
so i really dont know where this 800 coming from and this is the thing which bother me
thanks
here are some pics on my controler box

[cgo]

I see what you are saying, the g203v that come direct from gecko are set at 10u, there is a note of internal jumpers that are not for users but could be used to make the g203v compatible with different breakout boards (a call to gecko would be needed for this, I dont have any information other than the published info)

Looking at you picture, it looks like you have a usb breakout board ?
If this is the case then it has its own processor and maybe it is the reason you are or have to use 1/4 microstepping to get the right movement.
You could check with PMD if thats where you bought everything from, they will have the answer to that.

[cgo]

I forgot to ask is the steppers installed on the machine?
Did you measure the distance that it moved or just looking at mach readings ?

If you are bench testing it, try this, using a marker or even a piece of tape on the motor shaft, command the motor to move 5 full turns and count the motor turns, if they match then all is good.

[alan_3301]

It sounds like you are setting steps per inch and you need to set steps per mm

Either choose 787.401575 steps per inch or 200 steps per mm

Sound right?

hmm. I dont know where I came up with that.
nevermind.

[xakep4eto]

thanks for the replays everyone finaly after all day thinking and reading i fig out what was the "problem"
in the smoothestepper plugin there are 2 modes one is : step and direction , and the other one is Quadrature so i had is to the quadrature mode which i dont know what is about
after setting it back to step/dir everything works just as suppose to be.
so my next question is does any one know what is the Quadrature mode about ???
thanks again