Logic of Triac ATC operation for Mach3 upgrade

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sweep
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Logic of Triac ATC operation for Mach3 upgrade

Post by sweep » Wed 13 Jun , 2007 20:33 pm

Does anyone have access to a pnematic/electric flow chart or diagram that shows the logic of the toolchanger?
I am currently working with an expert (I ain't kidding either) in the field of plc logic controls in building a device that will drive the toolchanger from within Mach3.
I have explained to him the sequence of events that occur during the change but he is intrested in the change expressed in terms of inputs and outputs.
I have sent him the stuff from the downloads section but this doesn't really give him what he wants.
If anyone can help then it would be very much appreciated and will also, ultimatley, benefit everyone.
I have listed below the sequesnce as I have described it to him.

Thanks ...Richard

1) z axis moves to uppermost, home, position
2) x&y axis move simultaneously to home position.
3) spindle slows from normal operating speed to very slow speed (I can measure this speed if required)
4) Spindle stops at approximately correct position to allow new tool alignment. This is about 90deg after proximity switch and is achieved by electrical braking.
5) Empty tool holder of carousel presented to spindle
6) Tool released from spindle which makes final alignment of spindle.
7) Tool holder carousel descends to clear tool from spindle
8) Tool holder retracts clear of spindle
9) Carousel rotates by stepper motor to align new tool (only from tool 1 to maximum tool 6, never beyond eg from tool 6 to tool1. This would be achieved by rotation of tool carousel in opposite direction).
10) New tool presented to axis of spindle
11) Tool holder carousel raises, lifting the new tool into bore of spindle
12) Tool gripped into spindle
13) Tool carousel retracts to home position
14) System awaits next instruction

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Post by Denford Admin » Wed 11 Jul , 2007 10:08 am

Sorry - I missed this post - have you got it sorted now ?

I guess you have drive dogs on your machine ? I've never seen a T/C that needed to orientate as we stopped fitting the dogs some time ago.

I think the most time-critical part of the logic will be to capture the pulses from the proximety switch on the geneva cam. If yours is the same, you will need to see the input change twice for each tool position.

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Post by sweep » Wed 11 Jul , 2007 10:38 am

The tooling is BT35 which has two notches at 180 degrees. One of the tricky parts of the process is aligning these with the mating dogs :shock: on the machine spindle.
I have sent all my info along with a short video to the guy who is designing the controller for it and will let you know what he comes up with.
If anyone has any further comments please let me know so I can pass them on.

thanks ...Richard

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Post by sweep » Wed 11 Jul , 2007 10:38 am

p.s. what's a Geneva cam?

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Post by Denford Admin » Wed 11 Jul , 2007 10:41 am

I thought that was what the bit that spun around was called - you know the bit that grabs the toolchanger and gives it a nudge half a pocket position :?

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Post by Denford Admin » Wed 11 Jul , 2007 10:45 am

BTW - can't you remove the drive dogs ?
its not often we see tools slipping around - only when messing with the drawbar spring stack

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Post by sweep » Wed 11 Jul , 2007 11:01 am

I suppose I could remove the dogs but i haven't had wors back yet that this will be a problem.
To be honest as well, i'd prefer to do tool changes by hand than to risk damaging the machine spindle with a slipping tool ...unless you have a shelf full of spares :lol:
...Richard

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Post by Denford Admin » Wed 11 Jul , 2007 11:07 am

Of course - another thing that "springs" to mind is that the spindle is quite happy to run without a tool in, and the drawbar unclamped !

This, of course, has happened to me before :oops: and the top of the drawbar welds itself to the unlocking cam :shock:
Something to watch out for when setting up the new sequencer

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