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Automated Tool change support
« on: October 14, 2007, 07:20:07 AM »
Hi
I have been looking into PC based software to control my Emco VMC100 with auto tool changer, because the old cnc control is becoming un-reliable.
But can not seem to find any software which states tool change support, but have notice on this forum, people touching on the subject from time to time.

Can any one confirm if Mach3 would support this and if so how easy would it be to do, would it be the case of plug and play, if not who could I contact for guidance?

currently the tool changer works by combining the spindle and Z axis to tool change, Z axis releases the tool by moving in to a set position, which then engages the main spindle to the tool change mechs, so when the spindle orientates a set revolution per tool position, it select the required tool.

Any info would greatly received.

Adee



Offline Hood

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Re: Automated Tool change support
« Reply #1 on: October 14, 2007, 08:25:30 AM »
I am nearing the end of my Lathe retro fit, it has a 6 position turret and a 4 position toolpost. I used a PLC and a macro to control things. Was fairly easy to do but it takes a while to work out how, especially if like me you didnt know VB or how to programme a PLC.
 Cant really get clear in my head how yours operates at the moment so it may be easy enough to do, usually the biggest problem is the amout of I/O that you need for a toolchanger and the parallel port is limited, even if you have a second port. This is why you may need a PLC to get the I/O nesescarry.
  Can you post a few pics of the toolchanger? that might help a bit with seeing how it works.

Hood

Offline poppabear

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Re: Automated Tool change support
« Reply #2 on: October 14, 2007, 09:22:39 AM »
try this I looked at pick of a emco 100 vmc, it has 10 tool positions. NOTE, let me know if the spindle motor controls the turrent as opposed to a seperate servo.

'M6Start.M1s

Sub Main()

NumSlots=10
OldTurretPos=(GetOEMDRO(805))
OldToolSlot=Abs(GetOEMDRO(805)/36)
NextTool = GetSelectedTool()
NextToolSlot = (NextTool-1)*360/NumSlots


If OldToolSlot = NextToolSlot Then
SetCurrentTool(NextTool)
Exit Sub
End If

If NextTool>10 Or NextTool<1 Then
Message("Next Tool out of range")
Exit Sub
End If

'Replace x.********* with the machine coordinate position of your Z location for tool change
Code "G53 Z x.*********"     
While IsMoving ()       
Wend

MoveDis = (NextToolSlot-OldTurretPos)

 If Abs(MoveDis) >180 Then
   If MoveDis < 0 Then     
     MoveDis = 360 + MoveDis     
   Else     
     MoveDis = MoveDis - 360     
   End If     
 End If
 
'Use your extra C axis to drive your ATC turret spindle, unless your Spindle motor drives your Turret, if that is the case let me know, you can do a swap axis.
Code "G00 G91 C" & MoveDis         
While IsMoving ()       
Wend     

SetCurrentTool(NextTool)
Code "G90"
End Sub

'Scott
 
Commercial Mach3 & Mach 4, Design/Build/Retrofit CNC and Industrial machines.
http://www.ss-systems-llc.com/
Re: Automated Tool change support
« Reply #3 on: October 14, 2007, 11:48:30 AM »
Hi
Thanks for replying, yes the spindle motor controls the tool change rotation, it has an encoder bolted on the top of the motor, so I take it that controls what position it goes to when you select tools. I will try to post some pic's later.

Sorry if I seem a bit un-educated about this stuff, never really look to in depth about it.

What is a PLC? Is it a circuit board that controls the output from Mach3 to a driver or something?


Adee

Offline Hood

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Re: Automated Tool change support
« Reply #4 on: October 14, 2007, 01:33:16 PM »
a PLC is a programmable Logic Control, basically its a load of Inputs and Outputs, so for example you can have a load of limit switches as Inputs which tell it where the toolchange is and then it will do a corresponding output when it sees the right sequence.
 The outputs on mine are relays so I can control things like contactors, solenoids etc. You write a ladder which basically mimics imaginary relays, timers etc so that 1 input can turn on one output but if you have another input active at the same time it canl do a different totally different output. You can control the PLC from Mach over MODbus.

Hood

Offline poppabear

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Re: Automated Tool change support
« Reply #5 on: October 14, 2007, 04:04:21 PM »
Ok, it that is the case then your spindle motor will have to be able to be controlled by a step and direction signal.  If your spindle motor is analog controlled then you will have to set up a counter in a PLC. It would be best if your spindle motor/drive was step and dirction controlled.

You will need to "tune" your C axis to control your spindle where C will rotate your spindle accuratly in degrees.

The M6 below will swap the axis from spindle drive to a controllable C axis control (your spindle motor will temprorarily become a C axis servo or stepper).

here is the Macro

'M6Start.M1s

Sub Main()

NumSlots=10
OldTurretPos=(GetOEMDRO(805))
OldToolSlot=Abs(GetOEMDRO(805)/36)
NextTool = GetSelectedTool()
NextToolSlot = (NextTool-1)*360/NumSlots

If OldToolSlot = NextToolSlot Then
SetCurrentTool(NextTool)
Exit Sub
End If

If NextTool>10 Or NextTool<1 Then
Message("Next Tool out of range")
Exit Sub
End If

'Replace x.********* with the machine coordinate position of your Z location for tool change
Code "G53 Z x.*********"     
While IsMoving ()       
Wend

MoveDis = (NextToolSlot-OldTurretPos)

If Abs(MoveDis) >180 Then
   If MoveDis < 0 Then     
     MoveDis = 360 + MoveDis     
   Else     
     MoveDis = MoveDis - 360     
   End If     
End If

'Use your extra C axis to drive your ATC turret spindle, unless your Spindle motor drives your Turret, if that is the case let me know, you can do a swap axis.

SwapAxis(5,6)               'swaps the pins on your spindle with the  C axis

Code "G00 G91 C" & MoveDis         
While IsMoving ()       
Wend

ResetAxisSwap()     'resets your pins

SetCurrentTool(NextTool)
Code "G90"
End Sub

'Scott
Commercial Mach3 & Mach 4, Design/Build/Retrofit CNC and Industrial machines.
http://www.ss-systems-llc.com/
Re: Automated Tool change support
« Reply #6 on: October 15, 2007, 06:27:59 AM »
Thank you both Hood and Scott for your input.

I think you both have answered my question, “if it is possible to get a tool changer working with Mach3”

I suppose the next thing to do is research and cost up how much all this is going to be.

Adee