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Author Topic: Position or torque mode?  (Read 14502 times)

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Re: Position or torque mode?
« Reply #10 on: January 02, 2011, 06:55:26 PM »
I placed the txt file in the plugins directory, with the command GA,,,CA, but it did not change anything. V4.4.0.0 is the version of the plugin I am using.

Is there anything else I have to do to make that work?

I am posting a copy of my debug file.  It appears that mach is issuing a GA,,,X after my command.  How do I stop that?

« Last Edit: January 02, 2011, 07:07:20 PM by rforney »

Offline kcrouch

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Re: Position or torque mode?
« Reply #11 on: January 02, 2011, 09:44:47 PM »
You may have an interference between Mach3's slaving and the Plugin. Be sure that slaving is disabled. Also you will have trouble when using MPG functions which make use of the Galil gearing command. It is quits possibly the MPG that is overwriting your gearing command.
Kenny
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Re: Position or torque mode?
« Reply #12 on: January 02, 2011, 10:03:24 PM »
Kenny,

That worked perfectly. as far as the GA,,,CA command goes.  However, now it is only moving the one drive (A axis).  I may have to figure out how to write a brain to make sure that mode gets turned on, and revert to how I had it.

MPG is disabled currently.

Thanks,

Rob

Offline smurph

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Re: Position or torque mode?
« Reply #13 on: January 02, 2011, 11:04:59 PM »
I took a look at the debug file.  I didn't see any MPG commands in it.  It does show that you are using Mach to slave your Galil D axis to your Galil A axis.

The Galil plugin was developed primarily to enable the use of analog servos in Mach.  You are using your servos like steppers.  That being said, there is support for stepper motors in the Galil.  However, support for stepper motors is very lacking in the plugin, as none of the developers of the plugin have any stepper motors.  Stepper motors seem to work fine with a basic config.  But slaving is not the same command with steppers, as you have discovered.  

If you enable slaving in Mach, then the galil plugin is going to send a GA,,,X, as this is the proper thing to do with servos.  This basically negates your previous command of GA,,,CA.  So...  you need to disable slaving in Mach and do it all on the Galil.  These commands are what you will be needing in the GalilInit.txt file.  Remember, no slaving in Mach!

GA,,,CA  // slave axis D to master axis
GR,,,1    // gear ratio 1:1
GM,,,1   // gantry mode

(Leave the comments out of the file.)

This way, Mach only controls axes A, B, and C.  The Galil does all of the slaving.  But...  you will have to make sure that the gantry axis is square before Initializing the Galil from the plugin.  When Mach homes the gantry axis, it will think it is only homing 1 axis.  Mach will have no notion what so ever that there is a slave configuration.  This is fine, as long as you realize that none of the Mach slaving controls will be useful.

I updated the plugin code to take a look at the master axis motor type and do the right thing if it is a stepper motor.  However, that will not be available until the next release.  (I don't know when that will be at the moment.)  Maybe this will get you going until then.

Steve
Re: Position or torque mode?
« Reply #14 on: January 02, 2011, 11:39:39 PM »
Steve,

I appreciate your efforts to set me straight.  This does indeed make it "work".  However, the movement of the second x axis is very choppy, with mid-move stutters on the slaved axis.  Also, the drive is turning on and off (baseblock on the drive) under mach control.  Not an issue when driven straight from galil.

I do wish I had the knowledge and experience to tune these in Torque mode.  I do have the full version of galil tools, but the autotune feature doesn't quite get me there.  The noise coming from the gantry was horrendous. 

Maybe some more reading, and experimentation.  I do look forward to that plugin, though.  The Y and Z axis are running sweet!

Thanks,

Rob

Offline smurph

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Re: Position or torque mode?
« Reply #15 on: January 03, 2011, 02:24:36 AM »
You have mid-move stutters when the Galil is doing the slaving?  If so, then there is a mechanical problem.  Mach should be driving the X axis and the slaved axis should just follow it.

PM me your email address.  I have a new plugin for you to try.  MPG may be buggy in this plugin, as I just re-vamped the MPG code.  But it should do the right thing for slaving if the master axis is configured as a stepper axis.

Steve
Re: Position or torque mode?
« Reply #16 on: January 03, 2011, 03:13:23 AM »
Steve,

No mechanical problems, pinions are not touching the rack.  Under pure galil control, all is very smooth, even very rapid moves.  I have ditched the mpg for now, I am hoping a line driver will fix that.  If not, I will just shorten the cord.

PM sent.

Thanks!

Rob
Re: Position or torque mode?
« Reply #17 on: January 04, 2011, 07:29:08 PM »
Galil helped me tune the servos with acceptable performance.  

I am now trying to use velocity mode through the mach-galil plugin.

The x axis is doing what it is told, but the motion is very jerky, in contrast to the motions generated by galiltools with mach not running.  It is as if the gearing or gantry mode is being switched on and off.

On a reboot, I received no motion at all on the x axis, so I turned it off.

I read the debug file, and I think there are some commas missing after the SP command.

Any ideas?

Offline smurph

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Re: Position or torque mode?
« Reply #18 on: January 04, 2011, 09:34:40 PM »
Which plugin is this?  The one I sent you or the release from the download site?  There is definitely something wrong with the commas.  On almost every command sent!

Steve

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Re: Position or torque mode?
« Reply #19 on: January 04, 2011, 10:32:50 PM »
Ah ha!!!  You have slaving enabled in Mach and you don't have all of the axes mapped in the plugin config.  Only the first 3 are mapped but mach thinks you are using 4.

Steve