Are you serious when you say you see smoother motion out of your steppers when you use an external motion controller?

Whether or not you see smoother motion with a motion controller, would depend on how good the motion is from your parallel port.

A computer that runs Mach3 really good from a parallel port might not see any difference at all with a motion controller.

A computer that does not put out a clean pulse stream from the parallel port might see a big difference.

My preference is the UC300ETH. The UC400ETH or ESS are also good.

CS Labs are very popular, but it can be tricky to get probing to work with them. And they are expensive.

Stay far away from anything Chinese.

Hi,
yes, I took my steppers from 1800rpm to 2400rpm without losing steps and running more quietly and cooler.

I have a Ethernet SmoothStepper by Warp9. As I don't have examples by other manufacturers I can't definitely say that they are as good but that is my expectation.
It comes about because they ALL have hardware timers which are not subject to jitter like an interrupt driven software timer.

I run a dual core Atom MiniItx single board computer, Windows7 Embedded 32bit and NO graphics card. In short this is a very modest PC, I bought it about four years ago so
its still fairly new and so far has been reliable. It has an SSD so I expect another ten years yet. I used it with two parallel ports and Mach3 for three years and then switched to Mach4
and the ESS about 18 moths ago.

Despite the really wimpy PC it rocks along no problems. I have run the Mach4/ESS combination from my i7/16G laptop and it performs absolutely indentically to the wee Atom. The truth is
that you don't need a grunty PC to run Mach, its not a power hungry application, what it requires is consistent and continous service.

As ger21 points out if you have a well sorted PC that runs the parallel port really well you may not see a huge improvement. I always thought my parallel port ran well but I got a bigger improvement
than I expected.

I would chose a controller that has a Mach4 plugin should you ever wish to switch, just load a new plugin and away you go. At the current time the ESS by Warp9, the UC100,300 and 400 by CNCDrive,
the 57CNC by PoKeys,  the PMDX422 by PMDX, the HiCon by Vital Systems and CsLabs are all worthy contenders. If I understand the PMDX-422 is Mach4 only,that is it doesn't have a Mach3 plugin.
CSLabs have a Mach4 plugin but its a bit ragged yet and I've been less than impressed at their willingness to do anything about it, seems a shame because they have a good reputation with Mach3.
The best of the Chinese stuff seems to be XHC and I think is little better than junk and their Mach4 stuff just plain doesn't work.

Craig

 ???I'm planning a new build and have a couple questions regarding my shopping list if anyone cares to interject.
I'm a 3 license holder Mach3 advocate. I built a router, plasma (candcnc) and converted a mill.
My build is a 2 axis CNC Hotwire which neither has to go fast or be remarkably smooth. It's been awhile since my last build and things Ave changed from a stand alone controller box inclusive of a row of gekko drives and a big boat anchor transformer.
The now available components are so diverse and plentiful that it's dizzying.
Can I run a 64 bit Win7 or dust off that old Dell I knew would come in handy someday?
Who's controller is best or do I just go into a breakout?
Gekko still the choice for drives if I'm microstepping stepper motors?
Easier and straight forward is better, but now retired.....I have less time now if that makes sense....

Thank you for your replies and spending time, it is really appreciated!  I will have to weigh out whether to try out and external motion controller.  I get really good movement, but ever so often the carving on my S's are a little dirty, so after work is a thing for me.  But then if I make the machines move faster, will my operators be able to keep up?  Would it matter if they finished the jobs sooner but sat longer in between material changes?  Not sure that would be worth the expense.  I will just have to weigh it out for my shop.  Thanks again.

Craig,
What Ethernet SmoothStepper do you use?
Getting back into it and want to run a newer pc via ethernet to the motion control board.