Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: JohnHaine on December 15, 2009, 05:41:23 PM
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Hi all, well I'm slowly getting the rest of my lathe functions up. I've added a slotted sensor with opto-interruptor (salvaged from an old printer) to the spindle, and this seems to operate in that the LED on the diags screen goes off or comes on (depending on active low setting) as the slot passes the beam. However when the spindle runs the S_true DRO doesn't show the speed, only a steady zero! When running the LED blinks occasionally which doesn't surprise me as presumably the PC is sampling it and won't see all the pulses.
I haven't checked the pulse width as delivered to the breakout board but the slot width was calculated to comfortably exceed the Mach3 minimum requirement - would need to break out my old 'scope which hasn't been switched on in 10 years for this! (what an excuse...) - before I do this has anyone met this problem before and could suggest a solution please?
Thanks,
John.
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Make sure you dont have much if anything for the Index Debounce on General Config page. Other than that I think you are going to have to blow the dust off the scope.
Hood
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Make sure that you have Disable Spindle Relays (unchecked) and Use Spindle Feedback in Syn Modes (checked )
in prots & pins > spindle setup. You may want try lowering the Index Debounce and interval.
I will assume your using version 3.042.032 , you need to do a M3 to turn on the spindle for rpm to display.
If not any of those then you need to look at the opto output signal, trace the path from the opto to and from the BOB and to the pc.
RICH
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Having just been there this week, if you have not set one of these up before be ready for a challenge. Once up and running it is incredible but before that I wanted to kill everything. As mentioned above the low index debounce setting is important (0-1) if you can get away with it. The index led on the diagnostics doesnt really keep up (it bothered me too) if the motor is on but if you manually turn the spindle the opto sensor "sees" the leading edge very accurately and does it at speed too. I also get a random rpm displayed very quickly with erratic changes especially at low rpm the motor speed doesnt actually change just the display. It doesnt seem to effect anything and the numbers it displays are huge like 48924 rpm but synchronization is spot on.
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Thanks for all the replies, lots of things to try! I'll post again when I've had a go.
John.
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Well, I can report some progress. I unchecked the disable spindle relays box, which seemed to be the key so that I could "switch on" the spindle; also reduced the debounce number from 200 to 50. Now displays something which is related to spindle speed but approx half what it should be, and negative!
What is the significance of the "debounce interval" parameter please? I have this set to zero at the moment.
I will continue to play!
John.
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By the way Rich, is "doing an M3" what clicking the spindle button does?
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Debounce interval is for general inputs, Index Debouce is specifically for the Index pulse.
Have you tried less than 50 in the Index Debounce as usually any more than 1 or 2 can cause problems.
Hood
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YES, just click the spindle button ....even if you are turning the motor on manualy or you will not get an rpm readng. I actualy have M3 as part of my Iniatlization String in config...... NOTE THAT I AM "MANUALY" TURNING MY MOTOR ON. You may want to provide an iniatialization via a macro like it shows in the write-up in Appendix "C". This way you can always just type M1111 in the MDI and it will reset your lathe back to YOUR prefered state.
You may forget for instance, after threading. to provide a G94.
Index Debounce here is 10 and works, like Hood said, play with number some by lowering it.
RICH
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OK, thanks for suggestions, I have tried very low numbers including zero. The indicated speed is about half what I expect (but only going by the plate on the lathe, but I assume that Myford are right); it has a "-" sign in front of it; and shows a finite speed even if the lathe is stopped - I think I have some interference! Time to dust off that 'scope I think!
John
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John,
If you're using one of the last versions of Mach3 I think it might be related to what Art has discovered as an incorrect spindle speed showing with fast CPU computers. It should have a fix in the next version Brian releases.
Daniel
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Aha! I'm using version 3.042.032, the latest on the website (last week) - does this have the bug please? Is it just the speed display that's affected, can I use the index with confidence to try threading do you know?
Also, where are known issues documented please?
Thanks, John.
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Hi John,
Art mentioned on the other group that the last versions of Mach3 (which had the threading fixed) had problems with CPU speeds higher than 2.1Ghz. If that's the case for you then that's probably your problem. I don't know if it's only the speed display which is affected.
As a temporary fix you'll have to go back to some previous version (3.042.029 I think was the last one known as good). As I said the next version should be out soon with the fix in it.
Daniel
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John,
You may want to try the fix that is in the following link:
http://www.machsupport.com/forum/index.php/topic,8314.msg87047.html#msg87047
That fix was supposed to be incorporated into a new version of Mach, but...., I have yet to see it posted.
All know threading specifics that you need to be aware of, up to and including ver 032, are so noted in the Threading on the Lathe write-up. I never updated the write up because i thought a new version would be out
and only wanted to do it once. Oh well....sorry about that.
If the fix takes care of your readout i would stick with ver 032 for threading.
RICH
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Dan, Rich, thanks for the information. I will try the version with the fix - 032 seems to work properly with the Shuttle as well. Is the fix version effectively 032 with a patch? So I should run with that version as opposed to the 032 that I downloaded previously?
Just for info, I dusted off the scope (well, dug it out of the box where it had languished since I inherited it from my Dad - dusting would be a step far!) and fired it up. First surprise, the electrolytics didn't go bang after all that time! I looked at the index waveform, a nice clean pulse, no sign of bounce or noise, 3 ms low time at 660 RPM, so I don't think I have a sensor problem.
Thanks again for the help - it's great how people rally round in this community, I hope as I learn more I will be able to help too.
John.
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:(...the new version "failed to start because enable40dll was not found"...
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John
The "fix" is not the full mach 3 program. First you should load the standard .032 program. Then download the "fix" and copy and paste it into your mach 3 folder. When it asks if you want to replace the existing file, select yes. That should solve your problem with the enable40dll problem.
Peter
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Thanks Peter...yes, that's what I did effectively last evening...deleted the app from the folder and pasted in the new one. Speed DRO now works fine, shows slightly higher than the Myford plate, also now showing positive speeds! Still puzzling that when I stop the spindle manually it shows 500....
Anyway, now to venture on to screwcutting!
Thanks all again,
John.
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John
The remaining speed indication after the spindle has stopped, is I believe a known issue that Art is aware of. Screwcutting works well with the new arrangement.
Peter