Hi,
    I would like to know if there's a way to speed control the A axis rotation by adding a variable resistor to the SS input?, I added an 4th axis to my 3 axis Milling machine, and the setup is all fine, just need an extra stepper speed control to increase or decrease speed on A axis when not using gcode, need some help on this one.

The A axis maximun RPM is 1500 labelled on the sticker.

thanks,

Happy;
I would suggest a fob / jog dial or one of the pulse-generators wired into your stepper driver board. With steppers you energize 2 or more coils at once so just a regular resistor type speed control will only activate 1 coil limiting the power output of the stepper.
If your into electronics and programming look at the arduino.cc website and see how they wire up steppers to the arduino micro-controller. I have used the arduinos with nema 17 steppers with great success.
good luck
Doc

Happy;
Be sure you check on the operating voltage, current and power output in oz-in of your stepper so you don't under or overpower it
Doc

Happy;
I would suggest a fob / jog dial or one of the pulse-generators wired into your stepper driver board. With steppers you energize 2 or more coils at once so just a regular resistor type speed control will only activate 1 coil limiting the power output of the stepper.
If your into electronics and programming look at the arduino.cc website and see how they wire up steppers to the arduino micro-controller. I have used the arduinos with nema 17 steppers with great success.
good luck
Doc

hi wyzarddoc,
                    I have a pulse generator, it has 4 wire : +5v, G, G, Pulse, I wired Pulse to SS port 3 1A, and one of the G to 1B, and apply 5V anf G from Ss to Pulse generator, this did not work. Probably the Pulse generator's Pulse signal is different to a rotary encoder signal output.
Solve the problem by assigning OEm code 111 & 112 to input 11 & 12 for slow jog up & down, so everything is done within mach no need to use external hardware to control speed, as we thougth by adding an pulse generator would be easier but I was wrong. Next task is to add an rotary switch to count up or down the Percentage of Slow Jog rate display, what is the OEM for the Slow jog Rate percentage display?

thanks,

Ok Ithink i found it, the OEM code for Slow jog % DRO = 3

http://www.machsupport.com/MachCustomizeWiki/index.php?title=OEM_DROs

Using 2 tack switches 1 for Slow Jog +, 1 for Slow Jog -, assign those sw to input e.g. 11 and 12 so when pressed the DRO value changes.



then


If I want to use a rotary Switch for + & - by turning cw or ccw, would I need to write a code for this?

http://en.wikipedia.org/wiki/Rotary_switch