Hello,
Is it possible to automatically using the S word to switch gears in the gearbox? So, by pre-selection on a table (rpm/gear1-x) , then the assignment over S********* at the NC Program. It would be great if someone could help me there.
Best regards,
Tom

YEs it can be done BUT while it sounds simple it would be a very complex function in mach3. There would have to be various safeties in the code involved to prevent BAD things from happening. Also your CAM would have to KNOW that is cannot just change speeds out of slot whenever it wanted. The speed changes would HAVE to be done at predetermend points in the program.

How does your machine change gears ?

What is the gear change sequence of events?

What are the speed ranges for each gear change?

(;-) TP

In the moment the control is by HH TNC.
At first Stopped (M5), than the gearchange will done, while this, the spindle turns very slowly. After this, the S Word Speed, spindle turns with correct speed.
There are many Gears, hm, 10 or so (i have not seen directly the machine, i want to know at first, if it is possible to do this by Mach)
Best regards,
Tom

I have done this with a deckel fp4 cnc.

But i did it with a couple of M codes.

Example:

M13 is 25 rpm
M50 is 50 rpm
...
..

and so on.

Problem with a S code is when you make the wrong S then the gearbox will never find the right gear.
That is why i did it with M codes.

You change gears by Hand?  If so, I have a set up on my Bridgeport that involves a VB script made by Hood ( Thanks )and a brain.    Basically the brain looks for an input that is made when the high gear is engaged.  This way MACH knows if I am in high or low gear.  Then the VB script looks at my program if the S command is not in the range of that gear, it stops the program and asks me to change gear.  When that sensor sees that I am not in the wrong gear I hit enter and everything continues.

 

That red thing is a proximity sensor.

This might not be your situation, but here is the macro

 

rpm = GetRPM()
Setoemdro(1111,rpm)
newrpm = GetOemDRO(1111)                     
CurPull = GetOemDRO(56)

If rpm > 999 And rpm < 8501 Then       
Pulley = 1                             
End If 

If rpm > 99 And rpm < 1000 Then         
Pulley = 2                             
End If   

If Pulley = 1 And CurPull = 2  Then     
DoSpinStop()                             
While IsMoving()                         
Wend
Do
MsgBox "select main gear then press OK" 
If IsActive (InPut1) Then Exit Do       
Sleep  10
Loop
Else 
End If                         


If Pulley = 2 And CurPull = 1  Then
DoSpinStop()
While IsMoving()
Wend
Do
MsgBox "select back gear then press OK"
If Not IsActive (InPut1) Then Exit Do
Sleep  10
Loop
Else
End If


SetSpinSpeed( newrpm )