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Author Topic: Spindle Speed setup  (Read 7077 times)

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Offline jimpinder

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Re: Spindle Speed setup
« Reply #10 on: January 03, 2008, 01:30:18 PM »
My machine is a lathe with a milling head, run off the same motor. I have no pulleys on the lathe drive - that is more or less direct. There are a couple of pulleys on the mill head, but I have only bothered with one yet.

The way the automatic configuration seems to work is that the computer puts out a PWM signal to your driver board, starting at a low speed and ramping up, and then compares the speed it thinks it has set with the actual speed as per your spindle inde. Mine spindle seemed to be about 10% too fast. I would have thought then you would do it again and the computer would gradually adjust itself until it was correct, and announce itself.

It doesn't seem to matter how many times you calibrate, it always goes through the same procedure, but when you save, shut down and then restart the speed setting appears spot on (It is on mine anyway)
Not me driving the engine - I'm better looking.

Offline TonyP

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Re: Spindle Speed setup
« Reply #11 on: January 03, 2008, 02:29:33 PM »
I put the other 2 slots in this afternoon and I think it was worth it. I cut the same M6x1 thread in steel this time and it worked pretty well - fitted the nut anyway! So, to summarise, I'm now running with 4 index slots (1 at 2x width) open loop. I'm also using the timing input, which is mentioned in the manual, if you know where to find it. It's mentioned as a sort of aside in the spindle setup section.

Tony

Re: Spindle Speed setup
« Reply #12 on: January 08, 2008, 05:20:18 PM »
Hi Tony
Did the 4 slots work,
I have tried the 4 slots, 1x 50% bigger, It works but it doesnt.
I had it working perfectly, save settings a few times. shut down
when i restarted the next day, no go!. I made print screens so i could check my setups, and all are OK.
The revs seem to jump around. checked with a scope and the signals are square and clean.
I also noticed now the LED for spindle on Flickers on and of at about 1 hz
Any ideas
PS deleted the Mach driver and ran driver test to reinstall
I know you setup is different but could you perhaps send me a copy of you XML file so I can look what you have done , I may be missing something very simple
Thanks Friedrich

Offline TonyP

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Re: Spindle Speed setup
« Reply #13 on: January 09, 2008, 03:04:52 AM »
Friedrich,

I'll try & send an xml later on when I've woken up a bit! The lathe is on another PC.
There are two things that I would check: first, that I'm using the TIMING input NOT the INDEX - this was a change to my original 1 slot system. The other thing is to try the opposite polarity in 'Active HI/LO' for that input. One way works for mine, the other doesn't.
Don't know why it shouldn't stay saved though.

Tony

Offline jimpinder

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Re: Spindle Speed setup
« Reply #14 on: January 09, 2008, 04:00:17 AM »
Have you two tried messing about with the index debounce under general config.

I calculated the maximum speed my spindle would turn, and therefore the interval between the pulses I was going to detect. I ramped up the index debounce time so it was a little under the estimated pulse time. This seemed to give a much steadier detection of speed with far fewer odd readings, particularly at low speeds.

The only problem I have is at very slow speed - under 100 rpm. I think the mirror that I use as a reflector has a bit of a  distortion in it, therefore at low speed, I sometimes get a double "flash" which isn't blocked by the  index debounce. I might try and shorten the mirror, because it is too long anyway.

Even with index debounce, there seems to be a point where "harmonics" come in and I get a little distortion in the reading, but other than that I am pretty pleased with it,
Not me driving the engine - I'm better looking.
Re: Spindle Speed setup
« Reply #15 on: January 09, 2008, 05:44:46 AM »
Hi JimPinder
I have the port setup as timing, and i have played with the debounce, currently set at 4
The strange thing is that it all worked perfectly after i made the 4 slot disc, my biggest problem was noise but after earting the PC, controller and VFD to a common point on the lathe that all went away (Star topology). Even though the signal is clean the symptoms are a dirty signal
I think I must wipe the disc and start over.
Thanks Friedrich :(

Offline TonyP

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Re: Spindle Speed setup
« Reply #16 on: January 09, 2008, 02:43:04 PM »
Sorry about the delay, I got tied up with work.

Here's my xml.

Offline randyray

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Re: Spindle Speed setup
« Reply #17 on: March 26, 2008, 01:53:31 AM »
Maybe it's me...but I am using speed control and feedback...and it works......even the "Calibrate Spindle" stuff seems to work. What I can't figure out is where in any doc (pdf, forum, or wiki) does it explain the whole "Calibrate Spindle" thing. I can't find any reference to it. I'd like to see an explanation of all of the numbers and a little more than the quick blurb in the pdf about how the PID works (I know what it does)......but the calibrate doesn't seem to change the PID numbers....do I? When I change speeds on the spindle, it takes Mach a several seconds to settle down on an anticipated voltage to send it and I think this is the PID working but I need it to learn and tune itself up faster as it goes....this would mean seeing the PID numbers change a little over time.. Thanks for any help here?
BTW, I running a Hermes 1219 engraver (modified with a Sherline speed control and motor), running on a Jim Cullins/Bob Campbell Combo board and using a Fairchild  QRB1134 reflective object sensor....and turning about 500 to 25,000 rpm)
Randy Ray
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