Hi,
 sorry I posted that you can have four slave motors to each master, you can have five slaves!

Craig

Thanks again Craig. I still do not understand how a 4' gantry can be perfectly square without homing both a and y axis each time you start the machine. I have tried to put A on its own axis but Mach will not allow me to reverse the motor for some reason. I am still learning and will get there at some point but its a terribly frustrating road

Hi,

I have tried to put A on its own axis but Mach will not allow me to reverse the motor for some reason. I am still learning and will get there at some point but its a terribly frustrating road

Do you have a rotating fourth axis??? NO....then you have NO A AXIS.....fullstop. An A axis is rotary, whereas what you are calling your A axis
is in fact a linear axis motor slaved to it's Y axis master.

Once you have assigned a motor, say motor 3 per my previous example, then go to the Motor Tuning tab, select Motor 3 and set the Steps Per, max velocity
and acceleration exactly as the same as the master, Motor 1, per my example.

On the Ports & Pins tab of your motion controller plugin you will have to assign a Step pin and a Dir pin for the new motor, Motor 3.
If you need to reverse the direction of the motor  reverse the Dir pin, from active high to active low or vice-versa.

If your steppers never missed any steps then the two motors, Motor 1, the master, and Motor 2, the slave would always remain in step and te gantry would
never get out of square.

May I suggest in the first instance that you have just one active Home switch, normally on the master motor side of the gantry. When you home
or reference the axis both the master and slave will drive together until they hit the Home switch. At which point Mach will back both motors back a little until
the Home switch deactivates and zero's the machine coordinates for that axis. With any sort of luck you won't have to jiggle one motor until
the gantry is square, it should already be square and stay like that for months at a time. If it gets out of square you should try and find out why.
There are some gantry squaring procedures but start with the obvious and easy one....it may well be enough.

Craig

Great stuff from Craig, as usual. An A axis doesn't NEED to be rotary, but that said, on your router, it's unlikely you have a linear A axis either, so disable it!!

Hi Craig, thank you again for your reply. I completely understand your comment on the A axis but I disagree with your assessment. 1st Mach3 calls out the slave as an A axis and it must be set as such. 2nd you should ALWAYS home both sides of your gantry everyday. When you power off your machine all motors release and you can easily move one end of the gantry without noticing it and all cuts going forward will be off. Here are some instructions from Avid:
The following instructions go over the hardware and software settings required to set up Homing (including auto-squaring of your gantry for dual-drive machines) and Limits with our inductive proximity switches.

The switches themselves are fairly simple, but setting up the coordinated motion of the machine for homing is best done with the following step by step approach.

1. Proximity Limit Switch Installation
Homing your machine requires moving each axis towards its designated home sensor, so it is important to make sure your motors and sensors are installed in the correct physical positions on the machine.

On machines with slaved axes, it is particularly important to verify which axis is the primary Y, and which is the slaved Y (generally the B axis, however in some cases the A axis, depending on the controller you have), as the Y and slave Y sensors (again, B or A) need to be matched with the correct axis of motion for auto-squaring.

B or A   B or A (Y slave) Home   Sensor A/B is used for auto-squaring the gantry during homing, so needs its own port on your controller

Unfortunately I have an older machine and do not have prox switches but the purpose is the same. I am still struggling to get Mach4 to continue on to home the slave axis. I can home 10 times and maybe 3 out of the 10 times the A axis or Y slave will actually home and I can not understand why. Most times it will stop just as the Y master clicks and then retreats.

Hi,
if your two motors never lost steps then your gantry would never get out of square....and surely you want to achieve that,
in which case just one Home switch would work.

There is a thread running on the Warp9 TD forum, and as it turns out the ESS, when homing, treats the master and slave as independent and
will home both simultaneously each to their own Home switch. The axis is considered Homed only when both motors are homed.
Does that sound like what you want?

Go check it out.

Craig

There is a thread running on the Warp9 TD forum, and as it turns out the ESS, when homing, treats the master and slave as independent and
will home both simultaneously each to their own Home switch.

Yes I would love to see this thread. Would you happen to have a link I could use? I have spent a few hours looking for it now and not seeing it. Thanks for the help!!

Hi,

https://warp9td.com/index.php/kunena/7-general-discussion/9092-about-g31-and-ess

Craig