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Author Topic: spindle load feedback to mach3  (Read 12784 times)

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Offline Hood

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Re: spindle load feedback to mach3
« Reply #20 on: July 19, 2013, 07:00:04 AM »
This is the meter I used, 100uA-0-100uA.
http://www.andersmeters.com/shop.php?p=search_results&search_terms=CV18XCZ100UAS+

Here is a vid of it in action.
In the video I am spinning the chuck  (250mm/10Inch Dia) to 2000rpm pause for 2 seconds then to zero pause again then to 2000 reverse and then again back to zero.
As you can see the meter shows almost 150% load whilst accelerating but settles when at speed then when stopping there is approx a 100% load in the opposite direction, then vice versa with the reverse.

http://youtu.be/lZ7asQ2PBGQ


I was at one point going to input the analogue signal to Mach for doing things such as detecting tool wear but the issue I had was the +/-10v signal. I used a rectifier so that it was always 0-10v but of course that introduced a 1.4 or so voltage drop, I then messed around with an opamp circuit to try and redress the drop but in the end I got bored and just shoved on the analogue meter ;D

Hood

Offline stirling

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Re: spindle load feedback to mach3
« Reply #21 on: July 19, 2013, 09:09:52 AM »
in the end I got bored and just shoved on the analogue meter ;D
Wuss!  ;D

+/-10V -> bias by 10V -> 0..20V -> 4:1 pot divider -> 0..5V ADC

Offline Hood

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Re: spindle load feedback to mach3
« Reply #22 on: July 19, 2013, 09:30:16 AM »
If I had a clue what you were talking about I may agree ;D
Hood

Offline BR549

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Re: spindle load feedback to mach3
« Reply #23 on: July 19, 2013, 09:48:10 AM »
Long ago I tired the spindle load to monitor feedrate. It worked OK. Simply looked at spindle rpm VS requested RPM and IF it dropped beyond a certain percentage I adjusted the SSO to allow the spindle to catch up. I brought the VFD signal in with Modbus. Also built in a deadband to keep the SSO from constantly adjusting the feedrate.

BUT the end results it did not help anything IF you did your part with programing.

Might be useful to LOAD your machine to MAX the machine capacity BUT that does not always work out well UNLESS you are using a very expensive CAM to create Constant Chiploads as most manual or low end CAM programming does not create a constant load strategy and the actual chip load is all over the place.

Just a thought, (;-)TP



Offline Hood

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Re: spindle load feedback to mach3
« Reply #24 on: July 19, 2013, 10:27:56 AM »
Yes milling would be hard to do for such things, turning much simpler though as you feed per rev and one day we may even get CSS ::)
Hood

Offline stirling

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Re: spindle load feedback to mach3
« Reply #25 on: July 19, 2013, 10:36:58 AM »
If I had a clue what you were talking about I may agree ;D
Hood
It's the heat you know - I spec you're still up to your oxters in snow up there right?  ;D

Offline Hood

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Re: spindle load feedback to mach3
« Reply #26 on: July 19, 2013, 10:43:41 AM »
I kind of see what your talking about now, it was two things that threw me, 0..20v, was thinking you had the second . in the wrong place but now see you are meaning 0-20v and the other thing was I am wanting 0-10v so your 4:1 divider giving 0-5v was also throwing me.

Still not grasping exactly how it would work though, would have to think about it a bit more as the way I am seeing it at the moment the range would be much smaller as  the -10 would be 0 and 0 would be 5.

Now the weather, i wish it was snowing, I like the cold, this 26 deg C is killing me.

Hood

Offline stirling

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Re: spindle load feedback to mach3
« Reply #27 on: July 19, 2013, 11:14:19 AM »
The .. is a programmer (spit!) thing for range.

The idea was just to bias (add to) your input (-10V..+10V) to make it 0V..20V (still the same range (20V) but all +ve). Then just divide it by whatever to give you your ADC input range. So let's say for example your ADC is 10 bit with an input range of 10V. You just divide by two and then feed it into your ADC then map the ADC output in software (Brain/macro whatever). So an ADC value of 0 would map to your original -10V, 512 to ~0V and 1023 to +10V.

Me - I love this weather - 7 freaking years since last summer!  ;D

Ian

Offline Hood

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Re: spindle load feedback to mach3
« Reply #28 on: July 19, 2013, 11:40:37 AM »
See what you are saying now :)
I will certainly be doing this when/if Brian ever gets his finger out his arse and gets Mach3 sorted or Mach4 Turn done so I can get threading with the CSMIO without the annular groove. As soon as that is possible then the ESS will be getting replaced by a CSMIO/IP-A.

Hood

Offline stirling

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Re: spindle load feedback to mach3
« Reply #29 on: July 19, 2013, 12:01:09 PM »
I will certainly be doing this when/if Brian ever gets his finger out his arse
What!!! - You mean he's typing one handed?  FM - that's gotta slow things down alright ;D

Ian