[skdm]

Hello,

I'm running Mach 3 on my laptop and like the features and interface very much. Unfortunately I have a problem with my steppers, my setup is as follows:

- Aluminium CNC machine "frame" from ebay (kit without stepper motors and driver).
- Driver board and stepper motors are FET3 from Stepperworld with current limiting power resistors (the website has been shut down).
- PC has a 650MHz Pentium III, 256MB RAM (IBM T20) running a stripped down version of Windows XP.

Stepper World provides a program for testing their setup called VBStepDir. When I run this program at full tilt it runs all three axes smoothly in both directions apparently without missing a step. While doing this all motors sound extremely smooth and have a consistent hum to them.

I'm configuring the motors on Mach3 and I get a very rough sound coming from the steppers, and they are definitely skipping pulses. This is the case for all 3 axis. If I switch back to VBStepDir everything seems fine and it will lower and raise perfectly smoothly again.

I have played around with the velocities, acceleration, pulse widths (all the options in the motor tuning menu)
I have reinstalled a newer version of mach3 after that on my computer but the problem still persists.

Any help will be greatly appreciated.

Regards,

Stephane

[ger21]

1) Laptops are not supported with Mach3 when using the parallel port.
2) 650Mhz is well below the minimum specs for Mach3.

Try turning off the toolpath in Mach3 and see if it makes any difference.

Also, if Windows is installed in ACPI mode, try changing it to Standard mode.

[skdm]

Thanks for your reply,

I tried doing the two things you said but the problem is still there.

I'm going to try to get hold of a new "old computer" this week, I'm guessing that's the most obvious thing to do.

Thanks a lot ger21

[skdm]

I'm now using another computer which is powerful enough (Dell optiflex 780 with 4gb RAM, 2x3GHz) and the problem is still there. Works perfectly on VBStepDir but not on Mach3...
I really don't see what could be causing a problem except for a problem with mach3...

Any help would be appreciated

Thank you,

Stephane

[ger21]

Run Drivertest.exe in the Mach3 folder and see what it looks like. You should get a smooth, flat line with no spikes, and the pulse rate should remain very steady.

Also, go to motor tuning and try setting the pulse width to 15.

[skdm]

I upped the pulse width to 15um (I had never gone so high because of the recommendation above the box...) and now the motors run very smoothly.
Thank you so much, I think everything runs well now.

The driver test basically gave a straight line with many small regular spikes and said excellent.

Thanks a lot

Stephane