Need Help!- Mach3 CV settings vs. G-100 Plugin CV settings

[Bfarn]

Hi all,
I know that Constant Velocity settings are a huge topic, but I'm having a really basic problem...

Using the latest build of Mach3 (R3.042.020) with Art's G-100 plugin, I can't get CV to work at all. No matter what combination of settings I try, nothing makes smooth motion. This is on a variety of g-code jobs, coming from Art-Cam, Mastercam, and Mach3's own sample files. I've tried all the tricks like turning on plasma mode, turning off all CV settings, setting a g61 and back to g64....

The best clue I've got now was discovering a SECOND SET of CV settings in the G-100 plugin settings itself. I can't find documentation on it anywhere. Does anyone know if these setting conflict with the Mach3 settings? Or if Mach3 has to be in Exact Stop mode or any other nuttiness? My motors are tuned to be pretty zippy (250ipm with a .8 second ramp-up time to full speed), so that shouldn't be the problem. At this point I'd even consider it progress to have to motion get worse, just so I'd know something I'm doing has an effect.

Let me know if you've got any questions about my setup and, of course, let me know if I'm being an idiot and just missing the "Make It Work" button.

Thanks to all for being a great source of help.
--David

[neilw20]

1. If you rapid using shift and an arrow key do you get perfectly smooth operation on all axis? You should. If not something is consuming CPU cycles.

2. Does the driver test work properly?

[Bfarn]

Neil, Thanks for the speedy reply.
I don't think it's a CPU issue. I can indeed run each axis smoothly at full speed (with shift down), and the g-rex takes most of the heavy lifting off of the PC in terms sending out pulses and all that.

I haven't run the driver test since my initial setup, which was a while ago, so maybe there's something there... but it does do everything else just fine. It runs real smooth on jobs that don't have any curves in them.

I'll run the driver test next time I'm in the shop and I'll try some more settings, and I'll post agan with some specifics of what I've changed.

Thanks

[ger21]

You don't install the driver with the G100, do you?

[neilw20]

I have seen some weird code generated by some cam programs.
It might move say 6 smaller steps, all in the same direction, to get from A to F in the form A-B,B-C,C-D,D-E then E-F, where A to F is a straight line through all of the points B,C,D and E. This causes the interpolation routines to work overtime and consumes lots of extra CPU cycles.
Are the circles/arcs generated by lots of short straight vectors instead of G2/G3 style arcs?
You haven't said what your CPU speed is.
How much RAM do you have.
Are you using 25 KHz -- What are you config settings.
I was using a 600Mhz CPU with 256K and it worked fine until overloaded by CAM generated short vectors, which made it go a bit jerky.
I then stated using a 1.4GHz CPU/512K M ram with XP and mine got better, but with the occasional jerk.
I noticed that if Mach3 was displaying (and calculating) graphics then that was enough to overload it.
I am now running Windows 2000 and it has been perfect ever since.
XP just runs too much cr@p and goes off in to the weeds randomly and you cannot stop that rubbish do everything for everybody OS scheduling.
I even have the system networked and it does not jerk any more.
It could even be some low level USB background stuff when no USB appears to be being used.
I found using conventional PS2 mouse and non USB keyboard helped a lot.
You just have to stop wasting CPU cycles.
Is your parallel port convention motherboard or PCI ?
Some mother boards have been known to be bad regardless.
Ther are a lot of functions that can be emulated by the CPU, but they all consume CPU cycles. Eventually you hit the wall.

[ger21]

Originally Posted by neilw20 I have seen some weird code generated by some cam programs. It might move say 6 smaller steps, all in the same direction, to get from A to F in the form A-B,B-C,C-D,D-E then E-F, where A to F is a straight line through all of the points B,C,D and E. This causes the interpolation routines to work overtime and consumes lots of extra CPU cycles. Are the circles/arcs generated by lots of short straight vectors instead of G2/G3 style arcs? You haven't said what your CPU speed is. How much RAM do you have. Are you using 25 KHz -- What are you config settings. I was using a 600Mhz CPU with 256K and it worked fine until overloaded by CAM generated short vectors, which made it go a bit jerky. I then stated using a 1.4GHz CPU/512K M ram with XP and mine got better, but with the occasional jerk. I noticed that if Mach3 was displaying (and calculating) graphics then that was enough to overload it. I am now running Windows 2000 and it has been perfect ever since. XP just runs too much cr@p and goes off in to the weeds randomly and you cannot stop that rubbish do everything for everybody OS scheduling. I even have the system networked and it does not jerk any more. It could even be some low level USB background stuff when no USB appears to be being used. I found using conventional PS2 mouse and non USB keyboard helped a lot. You just have to stop wasting CPU cycles. Is your parallel port convention motherboard or PCI ? Some mother boards have been known to be bad regardless. Ther are a lot of functions that can be emulated by the CPU, but they all consume CPU cycles. Eventually you hit the wall.

As I said before, I don't think you install the driver with the G100, and without the driver running, and the G100 handling the step and direction signals, you shouldn't have to worry about the CPU cycles.

[Bfarn]

Wow, yeah - it looks like I've got some serious work ahead of me. I've been meaning to wipe the cnc PC for a while now, I guess this is as good an excuse as any. I'm running at the same specs as your second computer there - 1.5Ghz wit half a gig of RAM and windows XP. I never would have thought Mach3 would have challenged it, but.... well there you go. I'll run the task manager and see what kind of resources it's using.

I'll also check the basic Gecko install, make sure everything is in order with the drivers (or no drivers, or whatever ends up being correct), and tune the config settings.

It turns out I won't be able to get to the shop until the weekend now, so I guess I have time to do a bunch of homework on this stuff.

Thanks again for your help,
--David

[Bfarn]

Even if it's not a performance issue, with all of the iterations this machine has been through since I first started using it for CNC, I think a good clean start will do it some good.

I'll head over to the Gecko site and re-read all of their install docs with special attention paid to any Drivers issues. I'd sure feel dumb if I was using the PC to generate pulses directly in spite of having that fancy g-100 in there.