Davo,

I too faced motor stalling like you show in the video on my first build. Looked through the cables, voltages step durations etc. I considered that it could have been my Gecko G540 driver so changed that to individual drivers..no improvement.upped the voltage.. Nothing..Never thought that the parallel port would be to blame and definately did not want to spend any more money on the problem.

Every time you lose a step the motors need to reaccelerate. All good and well when they have the voltage to boost them but not so good otherwise. This can leed to stalling as the rotation speed is not ramped but stepped. Hate to burst your bubble but if you are having bench test problems you will have hair pulling moments when you finally build the machine. I know I did even when the bench test was perfect.


Some more reading on the mach forum: http://www.machsupport.com/forum/ind...?topic=9943.30

In todays CNC world it seems that there is just no point in using the lpt unless you have a linux cnc system. Even then a lot of people use a motion control card. For example when i tried Emc with an Asus motherboard it would not pass the test the software performs.
Arguably the first and foremost frustration in any build log seems to be the issue of lost steps for whatever reason,( drivers, noise, lpt port) so eliminating it is money will spent in my opinion. Second will be backlash but that can be managed.

Best regards

George