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Author Topic: Denford ORAC.  (Read 6588 times)

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Offline Kato

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Denford ORAC.
« on: April 08, 2006, 03:22:26 PM »
Hi, I would need some help to convert a denford ORAC.
Anyone who can help me?

I will keep all hardware just add the computer. One thing I´m stuck with is how to program the turret.

Re: Denford ORAC.
« Reply #1 on: April 08, 2006, 03:44:52 PM »
You can use a PLC OR you can use a MOD IO card. I use PLC's but others have had great luck with the MOD IO... The PLC (DL06) can be programed to run on it's own so Mach woudl tell the tool number and the PLC would send back that it was done.

Hope that helps
Fixing problems one post at a time ;)


Offline Kato

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Re: Denford ORAC.
« Reply #2 on: April 08, 2006, 03:51:17 PM »
Hi, Thanks for the quick answer. So a plc i what you use. Is it on an ORAC?

I found this in the Turbocnc forum,

"The toolpost has a DC motor driving a worm and wheel, and a rachet
with a click for each tool station. On the shaft holding the
toolholder there is an optical disk with three  tracks, and each tool
station has a unique coding on those three tracks.

What Denford did was to drive the motor in the forwards direction
until the correct code was read from the three tracks, then reverse
the motor against the rachet and leave it in a stalled condition.
This way tends to overheat the motor.

My circuit basically does the same, but when 'on station' only
reverses for three seconds then powers off the motor. I find that
cutting forces happily keep the rachet and pawl engaged.

I read the status of the three tracks into the parallel port of a PC,
and drive forwards until I get what I want, then using a 555 timer
run in reverse for three seconds. The motor is driven using an
L298 'H Bridge' circuit."

But i want Mach3.
He use the printer port on the computer and runs it macro.

Re: Denford ORAC.
« Reply #3 on: April 08, 2006, 05:49:47 PM »
with a little VB we can do the same with mach3...
Fixing problems one post at a time ;)

Re: Denford ORAC.
« Reply #4 on: April 09, 2006, 04:37:40 PM »

If you have a look around this group and the Yahoo ones you will se that I am currently working on an AVR based system for an Orac toolchanger. Mach then uses serial communications to talk to the AVR.


Re: Denford ORAC.
« Reply #5 on: May 10, 2006, 02:57:22 PM »
Hi to all using an Orac. This may be of help to those who want to get up and running fast.

I'm still fine tuning the macro but this works as is.

The hardware is as follows:

The 3 sensor wires are opto isolated and sent to the computer port
The motor is driven by an ouput line from computer to an L298 driver ( High for fowards and low for reverse) and an 555 timer to cut the reverse after 3 seconds. A line from the timer is sent to the port to notify job done.

I hope this is helpful and a thanks to Dave Murray for help with some obvious errors in coding.

'Unit toolpost;

'{toolpost unit for Mach3
'{Provides drivers to control the tool post on the Denford ORAC Lathe}
'{Attached to $278, pin 14 low starts toolpost to revolve, pin 15 }
'{ is a 'busy' bit, pins 11, 12, & 13 are data bits indicating which}
'{ tool is presented pin 11 being inverted}

'{Pin 14 going low starts the cycle, the program checks pins 11,12,&13}
'{until the correct tool is presented, then raises pin 14. This makes }
'{the toolpost reverse onto its location rachet. Program waits until
'{busy bit clears}

'{start toolpost  forcing pin 14 low}
'{stop toolpost   forcing pin 14 high}

'OEM Trigger #1 = pin 11
'OEM Trigger #2 = pin 12
'OEM Trigger #3 = pin 13
'OEM Trigger #4 = pin 15
'OEM Output  #1 = pin 14
Option Explicit

Dim TOOL,OldTool,SelectedTool,MaxToolNum,T,TSET,C

'Tool Changer Macro


Oldtool = GetDro (5) 'C Axis DRO used as a memory for last tool, I know this is a bodge but it works for me.

Tool = GetSelectedTool()

SelectedTool =0
MaxToolNum = 8      'Max number off tools for the changer

' do not allow tool number greater than number of turret positions
While tool > MaxToolNum Or tool < 1
Tool = Question ("Invalid Tool Requested, New Tool Number?")

If Tool = OldTool Then
Message ("Tool already selected")
Exit Sub
End If


T = Second(Now)
TSET = T + 1.5      ' ADD A 0.5 SEC WAIT
T = Second(Now)
Loop Until T > TSET

'OEM Trigger #1
Pin_A = IsActive (29)'INNER
'OEM Trigger #2
'OEM Trigger #3
Pin_C = IsActive (31)'OUTER

PinValue = 0

If Pin_A Then PinValue = PinValue + 1
If Pin_B Then PinValue = PinValue + 2
If Pin_C Then PinValue = PinValue + 4

Select Case PinValue
Case = 7
SelectedTool = 6
Case = 6
SelectedTool = 7
Case = 5
SelectedTool = 3
Case = 4
SelectedTool = 2
Case = 3
SelectedTool = 5
Case = 2
SelectedTool = 8
Case = 1
SelectedTool = 4
Case = 0
SelectedTool = 1
End Select

For c = 1 To 2000  '2000

Loop Until SelectedTool = Tool


Tool = SelectedTool

'Check Busy Flag
Do While IsActive(32) = false

'Send current tool to memory (C dro)
SetDro (5,tool)

Message ("Selected Tool" & tool)


Re: Denford ORAC.
« Reply #6 on: March 03, 2007, 09:35:21 AM »
Hi, As asked here is the circuit diagram and the current macro I'm using.

Hope this helps.