G64 Problems.

[ckirchen]

I'm trying to cut half of a circular bore into a block of aluminum with Mach2. After the G2 is executed (see code below), the machine stops for a moment and continues on. It happens whether the feed is fast (150 ipm) or slow (10 ipm). Though, it does become more pronounced as feed is increased (i.e. at 10 ipm, the stop is so brief that you need to keep a finger on the table to feel it). Also, increasing or decreasing motor acceleration seems to have no effect.

Here's the snippet from my code:

G64
G0 X0.8375 Y-0.3750
G1 X0.8375 Y0.0750
G2 X1.2375 Y0.0750 I1.0375 J0.0750 <--pause occurs after this line
G1 X1.2375 Y-0.3750
G0 X0.8375 Y-0.3750
M30

This is the exact code I was using to test the effects at different feeds. Angular CV Limit (on the Corrections screen) is set to 180, Motion Mode (in the State... config window) is set to Constant Velocity, and the pulse rate is set to 25kHz.

Any ideas why this would be happening? BTW: I'm pretty sure that Mach2 is staying in CV mode because the entry into the G2 is smooth and the green light does not flicker.

Chris Kirchen

[ger21]

IN the logic page, make sure "no angular discrimination" is not checked if you're setting an angle. Also, the manual is a little confusing. The way I read it, setting the angle to 180° would mean exact stop ONLY if you reversed direction exactly opposite.

I'd try both turning off the angular discrimination, and playing around with the angle settings.

The only thing you should see at different speeds, is the faster you go, the more the corner should get rounded off. Faster acceleration will minimize this.

[ckirchen]

Checking and unchecking "No Angular Discrimination" didn't have any effect. But when I checked "Plasma Mode", the motion became smooth. "No Angular Discrimination" did exactly what it was supposed to and I can now control the exact stops by playing with the Angular CV Limit.

What exactly is "Plasma Mode"? Is there going to be any drawback to using it for milling (other than corner rounding)?

Chris Kirchen

[ger21]

Plasma mode is supposed to "optimise" CV for use with plasma cutters. If it seems to work OK, thee's no harm in using it. I don't really know the specifics of it. But CV should work without plasma mode turned on.

[ckirchen]

In this particular operation, when the arc is entered, the motion is smooth. It's when the arc is completed that there is a pause. I've had other operations where the opposite happens. And others still where an entire operation (i.e. a pocket with corner radii) runs without pauses.

Could it be the computer? I'm running a P3 700 MHz with Windows 2000. The only software on it is Mach2, MeshCAM, CutViewer and AutoCAD. It is not connected to a network or the web.

Regardless, I'm doing a small production run right away that contains the Gcode in question. I'll post my results.

Chris Kirchen