I have just completed building my 5' X 10' Router - Plasma table. While tuning the motors I noticed that in the tuning screen using  the arrow keys I can run 600 inch per minute on my long axis X & Y with out stalling or missing a step. The same is true using the jog mode. However when I use gcode from MDI input or a gcode file my motors start stalling just over 350 inches per minute. Is this normal? Could possible using and smooth stepper are such cure this? I have a dell with a 3.3 ghz dual core processor 2 gig ram and only run Mach 3 on this machine. I am running win xp pro. I would appreciate  any ones advice or suggestions. 

Thanks


Larry

Hello Larry, welcome to the forum!

I have a few questions,
How does your driver test look?
Have you tried turning off the tool path display to see if that makes a difference? You can turn it off/on with the toggle tool path button by the reset button on the diagnostics screen.

The SS may not be necessary but would most likely fix it if either your driver test is bad or the PC is being taxed too much.  I would do a little more testing before I order any parts though I think but not sure what you have tried already.

Brett

Turning the display off cured the problem. After reading your post I remember reading that you need an independent graphics card and not one on the motherboard. So I guess I will need to  find a low profile graphics card for a dell omniplex. Thanks for your help. I also need to get some limit switches or at least figure out how to set the soft limits. I hit the z-axis instead of the x  and it ran up so fast and hard it hit the stop at the top and sheared a motor gear tooth off rather than stall the motor. I also lowered the velocity down do not need it that fast.

thanks

Larry

In light of your findings, you may want to consider a SS instead of the graphics card.  The SS may well cure your problem too and it looks like it will have a much longer life expectancy then the parallel port.  The parallel port is dieing and having a SS may allow to upgrade easier in the future. I can't guarantee any of this but I think I would consider it.

Here is a quote from an email I was copied on concerning soft limits and it sums them up is as a few words as I have seen.

Soft Limits are described in section 5.6.1.3 of the "Mach3Mill Install and Config Guide"

If you were trying to setup Soft Limits, then make sure that you have a consistent Homing strategy (since Soft Limits are based on Machine Coordinates) and double-check that your min/max values are correct - the easiest way is to home your machine, move each axis to it's furthest extent, and see what the values are (by click on the Machine Coords button on the Program Run screen).  Those values, along with 0, make up your min/max (ie. if X is 0 at one end of travel, and -43 at the other end, then your Max will be 0 and your Min will be -43; if Y is 0 at one end and +20 at the other, then your Max will be +20 and your Min will be 0)...

Brett