Denford Mirac conversion help

**Hellfire** · 07-11-2016

i have come to the difficult bit now, i am looking some help with a macro for a tool change. on the rear of the tool changer there is a rotary switch with 8 positions and another micro switch to tell the machine it has locked.
i have all the inputs reading on the motion controller.
when the motor goes fwd it pushes the tool plate out and then starts to rotate it, on reverse it draws the plate back in until the micro switch sees it.
should add i have no clue about macros.
cheers

**m_c** · 07-11-2016

What turret is fitted?
And are you using Mach3 or UCNC?
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If it's a Barfuldi TOE and Mach3, unless the UCNC controller has embedded macros/programs, it won't work. Mach3 macros only have a 10Hz update rate, and 1-200ms is far too slow to manage the turret locking sequence, which requires a maximum of a 30ms delay between detecting the strobe bit and activating the locking pin, and only 50ms to reverse the motor direction.

**Hellfire** · 08-11-2016

I am using mach3 through a uc300.
the turret doesn't have a locking pin, it meshs into a castle like gear. I can't seem to upload pics for some reason. The motor is controlled by an vfd, which I assume you can control the speed of.
the rotary switch is adjustable on the back to the turret

**m_c** · 08-11-2016

Sounds like you've got one of Denford's own DM turrets.
Is it like the diagram in this thread? - http://denfordata.com/bb/viewtopic.php?f=40&t=157
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Having had a quick look at the wiring diagram and the description in that thread, it seems to be a case of rotate turret clockwise until position matches, then immediately reverse the turret, at which point it should lock.
Depending on how fast the turret spins, you may have a problem, as with the 10Hz macro refresh rate, you have a 100-200ms reaction delay depending on timings. However I can't find any info on the timings required, so it'll have to be a case of try it and see.
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I've not done any Mach3 macro programming for a long time, so I'm hoping somebody will convert the following to the required Mach3 code-

Code:

While (TurretPosition <> CommandedPosition)
  ActivateTurretCW
EndWhile
  DeActivateTurretCW
  (a slight time delay may be needed here?)
  ActivateTurretCCW
While (TurretNotLocked)
  (Do Nothing)
EndWhile
DeActivateTurretCCW

You'll also want to add safety time outs at various places, as if the turret fails to lock, you don't want it to sit spinning endlessly, until you manually stop it running.
One option you do have, due to the turret using a VFD, is you could slow down the rotation to give Mach more time to respond.

**Hellfire** · 08-11-2016

yes thats the turret, thanks for that.
can i make use of the rotary switch on the turret, each contact = a tool. there is also a separate micro switch to tell its locked

**m_c** · 09-11-2016

Yes, you could use each contact for individual tools, however if you have the diode block as shown in the Mirac 1996 wiring diagrams, it would half the number of required inputs.
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The locked switch is also needed to check the tool change has been successful, but it should also be continually monitored to ensure the turret hasn't become unlocked when it shouldn't. In Mach3, you'd normally do that as part of the Macro Pump, but worry about getting the turret working first.

**Hellfire** · 09-11-2016

Assuming I was to get a plc to run the turret, what would I need.
How are the input and output signals between the bob and plc achieved. I would still need a macro for mach3 wouldn't I ?
then a programme for the plc.
Think I will go sit in the corner now and rock back and forth for a while