I've been struggling with lost steps with Mach3 and a post by one of the members at CNC Zone has informed me that he believes my problem is with using the PC at the same time that Mach is running a job.

http://www.cnczone.com/forums/diy-cnc-router-table-machines/337052-counter-balancing-z-axis-6.html#post2052068

In my test case I was running a 1.3hr job and at the same time I was on the internet after - about 50 minutes into the job my Z axis lost steps, significantly, nearly .75"

Can anyone confirm this problem and if so how do I maximize the chances of a successful run for long jobs?

I'm specifically looking for ways to shutdown services and applications in the OS (Windows 7) to increase the chances... also, will a multi-core CPU and or memory have any impact on this phenomenon?

Thanks,

Adam,

Adam,
You were given good advice by Gerry who is also a member on this site.

- Suggest you  dedicate a computer strictly for CNC and do not play around with it while running Mach.
- Make sure you have some headroom in the stepper tuning ie; velocity and acceleration settings

RICH

Thanks Rich, Gerry is an extremely knowledgeable contributor to both forums I listen when he types...

So, since this is a CPU cycle issue.. are there recommendations for the best possible setup? Gerry says he's running a Pentium III without issue how far back in time do I need to go for a stable setup, RAM, CPU, etc.?

Adam,

It appears that I'm going to need to either downgrade my PC or purchase an external (USB, Ethernet) controller. I'm leaning toward the ethernet controller...

Is there anything that is recommended from ArtSoft in regard to makes and models to purchase?

Adam,

Hi Adam,
I used parallel port for some years but found as you have UNDER NO CIRCUMSTANCES attempt to run any other software while machining.

A little while ago I bought a SmoothStepper ESS and it works a treat and is very much less sensitive to CPU load but guess what, UNDER NO
CIRCUMSTANCES do I run other software while machining! Someone on the forum described the situation 'when a personal computer is hooked
up to and controlling a machine it is NO LONGER a PC, it is a machine controller that happens to use Windows Operating software'.

You have been lucky in that you've only lost steps, wait until you have a serious crash because the machine lost the plot because you were
doing something else....

Craig

Thanks for the post.. in my case I was only milling a test piece but by the time I looked up the Z axis had already missed and was headed for a crash.

I'm thinking a smooth stepper is the way to go.. I'll just have to bite the bullet and fork out the dough for confidence sake.

Adam,

Hi,
kool, still wouldn't attempt the surf the net while machining tho...

Craig

My preference would be the UC300ETH.

I went with the smoothstepper... I hope this wasn't a mistake?

Adam,

Hi,
neither would be a mistake, both manufacturers have been around since the get-go of external controllers, both are good.

To my knowledge the UC100 has a Mach4 plugin whereas the UC300 and UC400 does not. Likewise the Ethernet SmoothStepper has a
Mach4 plugin but the USB SmoothStepper does not. Both companies have stated that they wish eventually all their products be Mach4
capable. Given the much greater IO capability of the ESS relative to the UC100 and have for my purposes the mandatory Mach4 plugin
leans me to favour the ESS.

Craig