Hi Sharpshooterser,

I am really not sure that Driver Test provides any useful information but according to section 2.2.1 of the manual the variation in pulse timing should be small. Your pic shows quite a high variation and that may well be the cause of your motor stalling.

As a guide the pulse timing line should look something like this; 

Is there a way to reduce it?

I think not, it is a function of the particular computer being used and just how that computer runs Windows. Laptops often produce bad results (as well as power saving problems) and Dell computers have been reported many time in the past as having poor results.

One way forward is to use an external motion controller (such as the ESS) - there are many to choose from but those that support both Mach3 and Mach4 will satisfy your current and perhaps future needs.

Hi,
sorry I agree with tweakie, that DriverTest.exe screenshot is rubbish. Its showing a jitter of 20us on a 40us signal, ie 50%. No wonder the steppers go cranky.
For reasonable service you want less than 4us jitter.

There are lots of little tricks that MIGHT, and I stress MIGHT improve the situation. A lot of those tricks belong to 'Mach Lore' and as the parallel port loses favour so does the
lore which generated the tricks.

About 18 months-2 years ago bought an Ethernet SmoothStepper and have never looked back, I recommend that course to you. I know a lot of dyed-in-the-wool parallel port affectionados
are going to jump up and down at my sacrilege but there you have it, ditch the parallel port and get yourself an external motion controller. If you buy Chinese rubbish you'll get what you deserve.
A lot of bleeding heart liberals are going to jump up and down at me castigating all Chinese made stuff as rubbish but I don't care. If you don't believe me just read the posts from the last month,
I will guarantee that 50 or more are along the lines...motors not working...supplier doesn't answer emails....cant read the Chinglish instructions. The list goes on and on.
Even if you decide to buy a good brand buy direct from the manufacturer or their nominated distributor...the Chinese have flooded the market with rip-off copy junk that doesn't work on places like Ebay and
Amazon. Before you part with any money get some advice or feedback from the forum about the device you are contemplating.

Craig

It was the crappy computer after all. Replaced it, and the machine is running much better now, with faster rapids.
However, the smooth stepper is something I will think about in the future, when the budget allows it.
Thank you for your help and insight