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CnC programs....Turbo-Mach3

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  • skunkworks
    replied
    and the pid has PID + FF0, FF1 and FF2

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  • skunkworks
    replied
    Sounds like a lot of things that are possible within linuxcnc.. Like gearing..



    (remember it does threading and rigid tapping well already)


    Originally posted by MaxHeadRoom View Post
    The Galil is as fast or faster than anything under Linux, the way I prefer is to download everything to the Galil buffer, the 32 bit dedicated Dsp processes the feedback up to 12mhz for servo, another features is the Advanced PID compensation with velocity feed forward.
    http://www.galilmc.com/support/custo...msoft-2003.pdf
    One feature I like is the gearing feature, ratio changeable on the fly, this includes allowing gearing the Z axis off the spindle encoder for threading.
    Or if you need to use two servo's as master and slave either side of a gantry table.
    Some previous applications.
    http://www.galilmc.com/support/smartmoves.php
    Max.
    Last edited by skunkworks; 10-23-2012, 06:23 PM. Reason: fix video

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  • MaxHeadRoom
    replied
    The Galil is as fast or faster than anything under Linux, the way I prefer is to download everything to the Galil buffer, the 32 bit dedicated Dsp processes the feedback up to 12mhz for servo, another features is the Advanced PID compensation with velocity feed forward.
    http://www.galilmc.com/support/custo...msoft-2003.pdf
    One feature I like is the gearing feature, ratio changeable on the fly, this includes allowing gearing the Z axis off the spindle encoder for threading.
    Or if you need to use two servo's as master and slave either side of a gantry table.
    Some previous applications.
    http://www.galilmc.com/support/smartmoves.php
    Max.

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  • BigJohnT
    replied
    Probably not a good fit for a control system that is real time like LinuxCNC. So as I understand it the Galil control and drive work together to control the motor position and you just drip feed the two letter mnemonic to the control. So the encoder feedback goes back to the Galil control board and closes the loop that way. I can understand Mack being interested as it you don't need any real time.

    Thanks for taking the time to explain about the Galil system.

    John

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  • MaxHeadRoom
    replied
    Whether PCI, Ethernet/RS232 or USB, a plug in just transfers instructions to the card by the Two letter mnemonic command, either by one to one basis or download a complete motion profile to the on board buffer, for large segment profiles, the buffer can be read before writing to avoid overrunning the buffer.
    This can be done manually from a simple communication program to a full VB written front end.
    The details of VB plug in, is outlined in the Galil VB tools S/W.
    There is also instructions for running under Linux, but so far I have not heard of an integration for EMC CNC?
    Some of the details of the Mach plug in is on the Mach Groups site.
    Max.

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  • BigJohnT
    replied
    Does Galil publish what a plugin needs to use their control cards?

    John

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  • MaxHeadRoom
    replied
    Galil themselves do not have front end software with their systems, only 3rd party or end user written using VB etc.
    Mach has a Galil plug in but I don't think they finalized it for a Lathe.
    The one that Galil refer to on their site for CNC is Camsoft.
    Over the years I have used a combination of a Legacy front end that Galil no longer support, unfortunately, Camsoft and VB custom designed.
    The closest thing I could equate Galil to is the Dynomotion products with Kanalog which allows the use of the AMC drives.
    For simple systems I have used a Maple Systems display and Galil two letter mnemonics.
    Max.
    Last edited by MaxHeadRoom; 10-23-2012, 02:34 PM.

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  • BigJohnT
    replied
    I nosed around on the Galil web site and could not figure out what software is used with the controllers, all I saw was that it takes simple two letter commands or something like that... do you have to use Galil software with their controllers?

    John

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  • MaxHeadRoom
    replied
    Some examples: Cincinnati point to point mills, 3 axis line punch, 3 axis Tube Cut of Lathe, various back gauges and 2 axis brake, Lathe with encoder controlled spindle, Mills for a few.
    Max.

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  • BigJohnT
    replied
    Originally posted by MaxHeadRoom View Post
    I have been using Galil Motion cards and A-M-C drives for around 25yrs now with NO feedback to the drive at all.
    The F.B. is solely by encoder back to the Motion controller. Which will handle up to 8Mhz encoder frequency.
    The drive is set up in the torque mode (Transconductance amp mode) as recommended by both Galil and AMC for closed loop systems such as this.
    Using the tuning program from Galil, results in very tight PID control that just needs a little tweeking after running the program, I have even got acceptable results using a manual sequence of PID tuning.
    Max.
    I can understand how that works I think... what type of machinery is this kind of drive typically used in?

    John

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  • MaxHeadRoom
    replied
    I have been using Galil Motion cards and A-M-C drives for around 25yrs now with NO feedback to the drive at all.
    The F.B. is solely by encoder back to the Motion controller. Which will handle up to 12Mhz encoder frequency.
    The drive is set up in the torque mode (Transconductance amp mode) as recommended by both Galil and AMC for closed loop systems such as this.
    Using the tuning program from Galil, results in very tight PID control that just needs a little tweeking after running the program, I have even got acceptable results using a manual sequence of PID tuning.
    Max.
    Last edited by MaxHeadRoom; 10-23-2012, 12:05 PM.

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  • skunkworks
    replied
    SparkeyNY - I would just try torque mode with the atom board and see if you get the results you want. (1ms servo thread)

    (I talked to peter also - and he said)

    [23:03:08] <PCW> Torque mode requires LinuxCNCs PID lop to run the velocity part of the loop
    [23:03:09] <PCW> this often requires more than 1 KHz sample rate (=~300 Hz bandwidth)
    [23:03:12] <PCW> but it may be fine depending on the machine mechanical bandwidth

    sam
    Last edited by skunkworks; 10-23-2012, 11:24 AM. Reason: adding info

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  • BigJohnT
    replied
    Originally posted by Sparky_NY View Post
    Motors with tachs are becoming far less common. Kelling motors for example. My 14x40 lathe has kelling motors and this is my next project (re-retrofit from mach). The lathe I just finished was velocity mode with a atom, I used the original motors and drives which had tachs. I was not unhappy with velocity mode in any way.

    I was told that the trend in cnc machines has moved to torque mode in more recent years. I threw the topic out in irc and mesa Pete said he personally prefers torque mode. Pete was also the guy that told me about probably needing to turn up the thread speed for torque mode and that atoms max out at about 1.6khz while some of the dual cores with hit 7 or so.

    I ended up concluding that in real world it does not make a whole lot of difference. I am told torque more is a bit more precise at the expense of being harder to tune. I love the atom computers with linuxcnc and would hate to switch.

    I got around the problem by finding a set of amc drives (BE30A8) that have provisions for encoder velocity feedbach in the drives making a tach unneccessary. So, the 14x40 lathe will indeed be velocity mode with the atom computer and mesa 5i25/7i77.

    The torque vs velocity thoughts are more for future retrofits and education purposes.

    My reason for looking at torque mode is mainly because of the lack of tachometers on a lot of motors.
    The feedback to the drive has nothing to do with the type of control input you use. Modern AC servos use encoder feed back to the drive and can be had in in control flavor you want. Kelling seems to target the low end hobby market.

    You can get servo motors with any feedback device you want, just last month I replaced two DC servos with resolver feed back with two AC servos with resolver feedback and drives to match. A couple of months back I installed a system with AC servo with a 2500P/r encoder and the matching drive which can use a variety of control inputs. These Panasonic A4 drives have High-functionality Real-Time Auto-Gain Tuning and Offers you "Position" , "Velocity (including internal 8-speed)" and "Torque" command control modes.

    John

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  • macona
    replied
    Back when I first re-retrofited my mill I used these little boards called Pixies. They were a step/dir to analog drive controller board. Handled encoder feedback and had a nice little program to tune the setup. They are gone now, but there is an open source replacement. At this time the only real viable option for EMC was the Servo2Go cards, thats how long ago this was.

    At the time a lot of people found that current mode worked better than velocity. Tuning was a lot easier. And as Sparky says, tachs are about as common as resolvers now.

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  • Sparky_NY
    replied
    Originally posted by BigJohnT View Post
    Why would you want to run in torque mode when most CNC machines run in velocity mode?

    Just wondering... I run my CHNC in velocity mode just fine with an atom mb.

    John
    Motors with tachs are becoming far less common. Kelling motors for example. My 14x40 lathe has kelling motors and this is my next project (re-retrofit from mach). The lathe I just finished was velocity mode with a atom, I used the original motors and drives which had tachs. I was not unhappy with velocity mode in any way.

    I was told that the trend in cnc machines has moved to torque mode in more recent years. I threw the topic out in irc and mesa Pete said he personally prefers torque mode. Pete was also the guy that told me about probably needing to turn up the thread speed for torque mode and that atoms max out at about 1.6khz while some of the dual cores with hit 7 or so.

    I ended up concluding that in real world it does not make a whole lot of difference. I am told torque more is a bit more precise at the expense of being harder to tune. I love the atom computers with linuxcnc and would hate to switch.

    I got around the problem by finding a set of amc drives (BE30A8) that have provisions for encoder velocity feedbach in the drives making a tach unneccessary. So, the 14x40 lathe will indeed be velocity mode with the atom computer and mesa 5i25/7i77.

    The torque vs velocity thoughts are more for future retrofits and education purposes.

    My reason for looking at torque mode is mainly because of the lack of tachometers on a lot of motors.

    Leave a comment:

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