When I bought Mach4 I was told that with a smooth stepper I could run a mill and lathe with the same machine at the same time.  So I bought a smooth stepper.  Well U can't open two instances of mach at the same time...  So what I want to do is use a hub to connect two machines to the smooth stepper and run the mill and the lathe simultaneously.. Is it possible.   I am also struggling with getting mach to control my lathe spindle speed.  I have a soundlogic stepper controller and VFD hooked to a 3phase motor.. However I can only get 10V to the speed pin on the vfd.(full speed).  I know it worked with mach3 but I lost a hard drive and all my setup data...So I am starting over with mach4.  Mill is working great with mach4.  Thanks for any help...

Sorry but you can't run a mill and a lathe at the same time with Mach4 and an ESS. Whoever told you that you could was perhaps being a little optomistic.
It may be benificial if you also post your spindle speed question on the Warp9TD forum. https://warp9td.com/index.php/kunena/index

Tweakie.

we have lath + mill in one machine
https://www.youtube.com/watch?v=hnBL3ox5rpQ
but its not simultany
we have also simultany working ( cnc + labeling ) on same time but for this we use 2 pc that conect together by ssh

Hi,
I believe Mach4 was designed so that it could run multiple instances, in which case you could run two machines at the same time.
It has not happened yet but it will one day.

That does not change the fact that the ESS can have only one trajectory planner master. So even if Mach could run two instances at the
same time you would still need two ESS's , one for each machine.

Craig

Do You suppose I could run one machine on the Smooth Stepper and the other on the DB25 Port.

if it so important to you ,connect 2 computers ,its much easy ,one will be supervisor ,so you enev not need 2 screen or 2 keyboard
you can send command to the slave to run directly in mach so user even almos dont know he use second mach