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Author Topic: Just thinking outloud (;-)  (Read 2641 times)

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Offline BR549

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Just thinking outloud (;-)
« on: October 25, 2012, 11:33:02 PM »
A while back a fellow mentioned about running his spindle as a spindle AND as a rotary axis by just useing the same pins for both the spindle step/dir and a rotary C axis step /dir. each set to its own spec in config so each would be accurate.

OF course he used a servo on the spindle.  The drive does not care WHERE the pulses come from and just does as it is told.  WHen you need the spindle call the M3 s2000 and mach sends pulses to make rpm as a spindle.  When you need rotary axis just make sure the spindle has stopped and call the G1 C180 F50 or what ever.

This would allow rigid tapping on demand. I would just create a software interlock to prevent both running at the same time. It would just create a faster than normal spindle speed getting extra pulses.

The servo would already have an index for Mach3 speed dro and to index the spindle for tool changes.



AND save having to Swapaxis() unswapp axis.

Anyone see why this would not work just fine?   Other than the cost of a 3kw High rpm servo and drive(;-) for the old BP Boss.


Just a thought, (;-)TP



Re: Just thinking outloud (;-)
« Reply #1 on: October 26, 2012, 02:45:38 AM »
I'm 100% sure that if you think of something, it will work.

You are probably the most talented guy on this forum.

Appreciate your time helping others.


Jeff

Offline Hood

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Re: Just thinking outloud (;-)
« Reply #2 on: October 26, 2012, 03:18:23 AM »
That method was used by me and Dan, and maybe more, before the SS supported SwapAxis()
Initially it wasnt allowed  in the SS to share pins between axis but Greg relaxed that option, think Dan was the guy that actually persuaded Greg to do that.
The only thing that was a concern to me was it was possible to command both at the same time so one had to be careful, not sure what would have been the consequences as I decided not to try ;D
Hood

Offline BR549

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Re: Just thinking outloud (;-)
« Reply #3 on: October 26, 2012, 09:12:14 AM »
I already know what will happen, the motor speeds up due to the extra pulses added to the stream. (;-) Lookin at the prices of big servos over here I probably will not be trying it on the BP anytime soon.

(;-) TP
Re: Just thinking outloud (;-)
« Reply #4 on: October 26, 2012, 09:48:03 AM »
Not sure if this would work but why not pass the data stream thru a double pole relay and have the spindle M3/M4 output to the relay coil when it is in service. Then when the spindle m3/m4 is not called the servo can still orient thru the other side of the contacts. (Guess I'm thinking outloud too)

Offline Hood

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Re: Just thinking outloud (;-)
« Reply #5 on: October 26, 2012, 09:50:49 AM »
Just wondering why you just dont use SwapAxis? Only reason I can think of is you already use 6 Axis so have none spare.
Using SwapAxis provides that software interlock you were thinking of trying to do.
Hood

Offline BR549

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Re: Just thinking outloud (;-)
« Reply #6 on: October 26, 2012, 11:25:31 AM »
One of the problems with swappaxis()  is IF you leave the spindle in a rotary configuration and shut down MACH3 mach will overwrite the XML with the current data. THEN when you startup again you will NOT have a spindle and NO easy WAY to undo it . You have to go back and  swap axis again.

I think a simple addition to the macropump or a brain could be used as a saftey interlock between the 2 axis running at the same time.  If one is running disable the other and vise versa.

(;-) TP

Offline BR549

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Re: Just thinking outloud (;-)
« Reply #7 on: October 26, 2012, 11:50:20 AM »
HIYA Jeff, thanks for the compliment BUT I am just another chip slinger on here. There are people FAR smarter than I am on here.

I just want to do things that the normal MACH3 does not do to the point I will spend DAYS/WEEKS working on things that in the end I either find a way to do it OR I fnd out ALL the ways that it can't be done.

AND those are BAD WORDS, "can't be done" (;-).

(;-) TP

Offline Hood

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Re: Just thinking outloud (;-)
« Reply #8 on: October 26, 2012, 12:10:23 PM »
One of the problems with swappaxis()  is IF you leave the spindle in a rotary configuration and shut down MACH3 mach will overwrite the XML with the current data. THEN when you startup again you will NOT have a spindle and NO easy WAY to undo it . You have to go back and  swap axis again.
That doesnt happen with the SS but I do seem to remember talk of it happening with the parallel port right enough.

Hood