Messages

651

General Mach Discussion / Re: Motor tuning

« on: December 02, 2009, 09:45:32 PM »

Just thought I update.  I was hitting wall with the pulse rate.  I figured that because when it stalled, everything stalled, not just the motor that was moving fast.  I tried upping the pulse rate but that didn't help, so I'm guessing it's a hardware limitation.  Anyway, I dropped to a 3:1 reduction and can now rapid all day at 500IPM with an acceleration of 30.

652

General Mach Discussion / Re: Motor tuning

« on: November 25, 2009, 09:27:04 PM »

Steps per inch are 3750 figured after the reduction of 5:1.  It's running through the parallel port.

I had not figured out the RPM, but if my math is correct, that's probably the problem.  In the past, I've noticed that steppers seem to hit a wall at about 1000 RPM.  In my case, I'm moving .540 per revolution.  800 / .540 = 1481RPM.  Please correct me if my math is wrong.  I'm zoned out on decongestants.

Perhaps I'll try dropping to a 3:1.  That should bring the steps per down to 2250.  That should bring the RPM at 800IPM down to about 900RPM, provided the increased torque isn't an issue.  At the very least I should be able to get the speed up to 500IPM.  500IPM at 3:1 is about the same RPM as 300IPM at 5:1.

Just out of curiosity, would a smoothstepper overcome this RPM limitation?

653

General Mach Discussion / Re: G Code Error

« on: November 25, 2009, 06:15:34 PM »

G3 is modal - stays in effect until changed.

Put a G00 or G01 in front of the Z move

Thanks very much...That's what I get for messing with too much at one time.  I was playing with some posts and that got changed.

654

General Mach Discussion / Motor tuning

« on: November 25, 2009, 05:06:38 PM »

I have an interesting issue.  With speed in motor tuning set to 800IPM I can job the machine easily at that speed, but when I issue a G0 command the motors stall toward the end of the path.  I can only get 300IPM reliably from a G0 command.  The machine is a plasma table with steppers.  I was tinkering earlier and moved the pulse and direction pulse width up to 4 and it ran great at 600IPM on a test file, then after a hour or so I went back and tried running the same file and the motors were stalling again.  300IPM seems to be the magic number.  I just can't quite figure out why it will jog at 800IPM all day long but won't rapid from G code at more than 300IPM.  The acceleration settings didn't even make much difference.  Motors were still stalling set at 600IPM and an acceleration of more than 1 second.   At 300IPM I can set the acceleration to .05 seconds with no problem.

Is there something I'm missing or should I just be happy with 300IPM?

655

General Mach Discussion / G Code Error

« on: November 25, 2009, 04:52:19 PM »

I have the following code that I'm running as a test just to see if everything moves the way it's supposed to.    I'm getting the following error...

R ijk words all missing for arcline 15.

The program stops on line 15 and generates this error.  I'm not sure what this means considering that this line is a Z retract move, not an arc in the XY plane.  Has anyone seen this error before?  Other than this error, the machine runs the program as it should.

Thanks...

N0 T1M6
N1 G0 X0.0000 Y0.0000
N2 G0 X18.5195 Y12.4166
N3 G0Z-0.125 M3 G4P1
N4 G3 X18.0140 Y11.9222 I-0.0020 J-0.5036 F120.0
N5 G2 X16.5481 Y8.0635 I-5.9863 J0.0664
N6 G2 X12.3093 Y5.9928 I-4.5431 J3.9260
N7 G2 X8.0635 Y7.4519 I-0.3134 J5.9952
N8 G2 X5.9928 Y11.6907 I3.9260 J4.5431
N9 G2 X7.4519 Y15.9365 I5.9952 J0.3134
N10 G2 X11.5374 Y17.9975 I4.5431 J-3.9260
N11 G2 X16.2534 Y16.2531 I0.4648 J-5.9905
N12 G2 X18.0140 Y11.9222 I-4.2339 J-4.2445
N13 G3 X18.5084 Y11.4167 I0.5036 J-0.0020
N14 M5
N15 Z0.125    (Generates Error Here)
N16 G0 X0.0000 Y0.0000
N17 G0X0Y0
N18 M30

656

General Mach Discussion / Re: Macro Question

« on: November 22, 2009, 08:14:12 PM »

Excellent...Thanks very much.

657

General Mach Discussion / Re: Macro Question

« on: November 22, 2009, 07:51:51 PM »

Cool, Thanks.  Is there a list of available OEM DRO codes for custom use?  I have the list of OEM codes that Mach uses.  Can I just make up a number as long as it's not being used?  I saw a few labeled reserved, but some of those must be in use in the THC300 profile because I get odd results when I try to use them.

658

General Mach Discussion / Macro Question

« on: November 22, 2009, 05:38:48 PM »

I'm guessing that a macro is the way to go here, but not sure how to use them.  I want to execute a script from within a G-code program.  Would I write the script as a macro, name it...say M123, place it in the macro folder, then call it from G-code by placing M123 in the code?  I know how to use button scripts, just not sure how to execute VB script from G-code.

Thanks...

659

G-Code, CAD, and CAM discussions / Re: The plasma turn on and off on X=0, Y=0.

« on: November 22, 2009, 09:33:45 AM »

You just need to tweak your post. I use Artcam and the torch turns on when it should after touching off with a G31.   I made a post specific to my machine. I've tried Sheetcam as well and it produced the same results after making my own post.

Artcam gives you a little more control as it's posts allow you to add code on plunge and retract moves. It appears that Sheetcam puts the torch control and touch off code in a first feed rate move which can produce some strange results sometimes.

660

General Mach Discussion / Re: creating small circles

« on: November 20, 2009, 11:54:47 PM »

If I were after a more exact dispensing method, I'd probably use a screw driven syringe rather than air pressure.  You'd have far more control with a screw driven dispenser.  You could drive a screw syringe with a rotary axis.