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Author Topic: Bridgeport Knee Mill Conversion?  (Read 158987 times)

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Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #220 on: June 03, 2016, 03:30:16 AM »
Sorted it out :)

Just use an output in Mach for each profile - active low, no other use. It comes on as soon as Mach loads and stays on regardless of reset state etc - this output can then control the respective contactor for the VFD needed for that profile.

The supplies will also go through the E-Stop system but this means that the whole startup is now just a matter of clicking on the correct Mach profile :)

Now, lets look at the Z axis...

I am intending to bolt the aux spindle onto the main quill shaft, this means that my Z travel will be reduced but not drastically i think.

It also means I need two Z home positions - can I use ONE Z home switch at the lower position and use the Z home-offset to tell the system where the home is respective to the profile in use??

Questions-

If i have one home switch in the lower position and the head is already above that switch, what happens when i ref-all??

Is there a smart fix for Z upper limit switch or do I have to try and fit TWO limits switches in at the top??

Getting there :)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #221 on: June 03, 2016, 03:41:12 AM »
Hmm, bench-top tests seem to look promising - with a home switch offset of 50mm, when i do a ref-all it moves to the switch, stops, moves off, then reverses 50mm. I think that is just what it needs ?

If the switch is already closed when ref-all is called, it just backs off slowly until it opens - nice, BUT the switch trigger MUST be continuous and not just a passing trigger so a long switch cam will be needed there.

Limits??
« Last Edit: June 03, 2016, 03:44:21 AM by Davek0974 »
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #222 on: June 03, 2016, 06:48:10 AM »
Rough draft of power wiring and e-stop circuit...

Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline mc

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Re: Bridgeport Knee Mill Conversion?
« Reply #223 on: June 03, 2016, 10:42:37 AM »
Couple things from a quick look at the diagram, you'll need a limit override switch, and do you really need to have the power for each servo drive use a separate contact?
The same could be said about the ESR relay.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #224 on: June 03, 2016, 10:51:09 AM »
Ooh, good point re the override switch, forgot about that one :)

No real reason for the multiple ESR, just  the way it evolved, will alter that one.

No harm in having the drives on multiple contacts, its a common style of contactor so no need to combine.
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #225 on: June 03, 2016, 01:17:33 PM »
you'll need a limit override switch,

Hmm, thinking on the drive home  ;), I can see one reason when that would be needed - if the soft-limits fail and the Z axis rams the head right up or down - there is no hand wheel on the Z axis so no way to get it back down again, although I could simply reach up and spin the pulley by hand.

But apart from that, if the X or Y axis runs off the end then they can be rewound before pressing reset?

An E-stop loop would not be bypassed by the limits override so thats ok.

Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline mc

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Re: Bridgeport Knee Mill Conversion?
« Reply #226 on: June 03, 2016, 03:24:07 PM »
You do have the benefit of being able to move things manually, so you could probably manage without an override button.

I think it would probably be a good idea to wire up your control box to allow for the possibility of adding one later though. Have the limit switch loop come back to a terminal in the control box, before connecting to the E-stop loop, so if you do need to add one later, you've got a nice convenient point to wire one in, with minimal rewiring needed.

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #227 on: June 03, 2016, 03:29:51 PM »
Yes i like to wire that way anyway, makes things much easier to trace issues later on when the external stuff comes in on a terminal strip, one by one, no hidden loops etc.

I would like to think that once homing and safe-limits is up and running the only time the hard limits would be it is after a runaway drive and I've not heard of that yet;)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives

Offline Hood

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Re: Bridgeport Knee Mill Conversion?
« Reply #228 on: June 05, 2016, 11:31:16 AM »
Problem with having lost of I/O available is you soon find things to do with it and end up with one short :D

Hood

Offline Davek0974

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Re: Bridgeport Knee Mill Conversion?
« Reply #229 on: June 05, 2016, 11:33:35 AM »
I have a bit more on the MPG module ;)

My list is only about half-capacity at present, plenty to play with :)
Bridgeport Mill, Mach3 V062, CSMIO-IP/A controller, AC Servo Drives