View Full Version : Need Help! Proximity switches and Mach3

06-19-2014, 11:10 PM
I have the PRO4848 machine with the DIY electronics Nema 34 motors and the PMDX-126 and 133 board. I have been having a horrible time trying to get the machine to home.

The problems is that when you hit the Ref All Home button in mach3 the machine starts to home the Y-, when it gets there it stops then heads to the X-, when it gets there it stops then it trys to home the A axis by itself which is slaved to the X and that pulls the gantry out of wack and skews the gantry and I have to hit the estop. I have tried several different items like verifying that the wires are correct, and that I actually have the x sensor on the x axis side and not the x prime side.

I even tried reprogramming the ref all home button to this per suggestion by Art in another thread, and yet that did not do the job.....puzzled!

"Art wrote....> Common problem. When you home , the slaving is disabled till the home is
> done. This is done to auto-square the gantry of such a system, thats why
> the lack of slaving when you stop the homing.. The solution is to make the
> homing go in the correct order. This is done by modifying the Homing
> button.. If you open the 1024.set file in the screen designer and double
> click the "Ref All-Home" button, you will see the code is
> DoButton( 24 )
> DoButton( 23 )
> DoButton( 22 )
> DoButton( 25 )
> This basically calls the Z, then X then Y and A homes. This needs to be
> changed to ..
> DoButton( 24 ) ' this homes the Z
> DoButton( 23) ' this homes the Y
> RefCombination( 9 ) ' this will home the X and A at the same time.
> RefCombination accepts a number where X = 1 , Y = 2, Z = 4, A = 8, you
> simply add the values of the axis
> you wish to home, so X + A = 9..
> The squaring will be automatic and can be adjusted by your settings for
> the home position of the switches..
> Thanks,
> Art
> New Page 1 (http://www.artofcnc.ca)

Art also wrote this... and I found the complete "Refcombination" listing here....

"Art wrote.... The home switches, (which may be set to the same input as the limit
switches), are used only for homing. The axis will move to the switch, then
slowly move off.

The program by default does one at a time, because thats the most usual
combination. YOu CAN move any combination at once by editing the RefAll
buttons script. There is a command called RefCombination( n ) which will ref
any combination of the axi s. N is calcuated by adding the following

X - 1
Y - 2
Z - 4
A - 8
B - 16
C - 32

06-20-2014, 04:02 PM
I believe the problem has been solved. Ahren from CNC Router Parts suggested I make a change in the general config section in mach3 to check or enable slave to home. Once I did that all axis seemed to behave properly and home without skewing the gantry. I will come back and post a screen shot for an example.

12-15-2015, 05:23 PM
did you get a solution to this ?

12-21-2015, 01:58 PM
Yes I made a change in the general config section in mach3 to check or enable slave to home.