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Author Topic: Problems threading on the lathe  (Read 330214 times)

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Offline ART

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Re: Problems threading on the lathe
« Reply #230 on: April 13, 2009, 08:50:06 AM »
Hi:

  Yes, I have been thinking the same thing. And I will be adding a selection to turn off compensation as well as a diagnostic for those vfd's that self coorect. In fact with self correction internal correction may not be
necessary at all. But I have some corrections to implement first to try to stabalise the readings a bit more. Might as well make it as tight as it can be before modifying the methodology used..
I may try to get an enocder to work yet.. I suspect it can be done but I'm still looking into it..

Thx
Art

Offline ART

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Re: Problems threading on the lathe
« Reply #231 on: April 13, 2009, 02:10:21 PM »
Hi Guys:
 
  This test driver file is for the normal version of MAch3 , whichever version yor using. This driver has been optimised for timing
as I discovered a few things I could do. Hopefully it works fine on your machines. IT should be more accurate as to the end frequency
it settles on, and it shoudl be better at timing resolutions. Run a driver test before and after installing it, Id liek to see any screenshots of
before and after. Your free to use this driver with your original Mach3 , the Spindle RPM's may be a bit better.
 

CHIP:  This version shoudl also stop your frequency locking problems .. Let me know if it handles it for you, no mouse motion or
anything should be required to make it lock in properly. I get 25007 PPS with this driver on 25Khz..

Thx
Art

Offline ART

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Re: Problems threading on the lathe
« Reply #232 on: April 13, 2009, 02:26:46 PM »
BTW:

  Couple question for you all...

If you use SS, hwo is it in threading.. Any troubles or are the threads good?
Same for PP except for the problems we know of in long threads..

Thx
Art

Offline ART

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Re: Problems threading on the lathe
« Reply #233 on: April 13, 2009, 04:02:37 PM »
Hi Guys:

    One last small note. Im about ready to release what shoudl be a fairly good driver test using multiple slot wheels, this is a new mode specially
designed to take into account the problems we seem to be having on single slot, Ive come up with a new theory on controlling the speed more
dynamically and it should be possible to turn off the spindle, the Z will stop, turn it on again and the Z will accelerate up with the spindle.. if it all works.

 Is there anyone with multislot capability that could test such a thing on the printer port.. All it will require is a special driver, standard Mach3 should
work fine with this new driver mode (Locked_Spindle_Sync_Mode).

  The new algorithm should, if my theory holds :-), allow for a total stop of the spindle because it remembers the slowdowns and speedups. While it doesnt
correct for speedups, there is no way to do that, as long as the spindle doesnt go faster than it is going at time of initial G32 motion, the real position should be
remembered across the entire distance of the thread. within certain limitations of error.

 Post if your capable of testing, all youll need is a multislot wheel, 90 slots will have a limit of perhaps 5000-6000RPM on the spindle, 180 slot woudl have a limitation
of 2500 - 3000RPM for synced speed by my numbers at 25Khz mode. A REAL encoder can be used, BUT youd be real limited unless its a low line count. A normal 2000 line count encoder woudl limit you to 60RPM for example .. and woudl require a special test build just for you. :)

Thx
Art


 

Offline Chip

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Re: Problems threading on the lathe
« Reply #234 on: April 13, 2009, 06:50:52 PM »
Hi, Art

The last driver you posted requires far less mouse movement to lock in the Pulse Frequency now, But it will still drop off with no movement of mouse,

All though with my large Cut Screen and running a G Code file it will lock in while the code is Running, 25K set shows 38,456 Pulse Frequency.

Good CPU, 25K shows 24,997 Pulse Frequency.

Thanks, Chip

Offline ART

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Re: Problems threading on the lathe
« Reply #235 on: April 13, 2009, 07:21:34 PM »
Hi Chip:

 Thx, I suspect htat machien is pretty far gine, the internal timers are acting up badly if thats the case. Not sure I can make it tighter than that, but we'll see how others come out in this test, it may shed some light. :)

Thx
Art

Offline RICH

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Re: Problems threading on the lathe
« Reply #236 on: April 14, 2009, 10:22:37 PM »
ART,
If i made a multi-slot disc would one of the slots need to be bigger and the width basis for the others still the same as a sindgle slot???? 

RICH

Offline ART

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Re: Problems threading on the lathe
« Reply #237 on: April 14, 2009, 11:48:10 PM »
Rich:

  Hard to say, still playing.  If you use a separate index for triggering then youll need 2 sensors, otherwise one slot
will have to be wider than the others..

Art

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Re: Problems threading on the lathe
« Reply #238 on: April 20, 2009, 04:45:17 PM »
Hi Guys:

 Just in case anyone has a spindle with an encoder on it, this test driver and plugin will sllow you to test RPM display and sensing with
either an encoder or slotted wheel with a separate index pulse..
 
  It will not yet allow threading, but will shortly as Brian releases a new updatedd release version to allow the pluin to take over the RPM
display. The Plugin will however, display the numbert of slots, the current RPM , and in G32 mode how much the spindle is slowing.

 This is really just a test of RPM display using encoders or slotted wheels.

Thx , any experiences aprreciated, this driver/plugin can be used with any recent version of Mach3.

Art

Offline ART

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Re: Problems threading on the lathe
« Reply #239 on: April 20, 2009, 04:46:42 PM »
Oh.. just a note..

  You input the index pulse to INDEX  and use TIMING for the input of slotted wheel, OR turn off TIMING and use INDEX and Encoder#4 inputs as the encoder count input.

Thx
Art