Help please. Dip switches and mach 3 settings

[Radu_Andrei]

Hi.
In march I finally managed to get the thing going, and was super exited and did quite a few jobs with it, then for the last month and a half, I was stuck with some other things and did not touch the cnc, and last week had in mind to get back to it, only to notice that the pc (gigabyte ga-8vm800pmd-775-rh, ddr2, 533mhz) which worked perfect for some time, including 10 hour straight in some cases, now turns off without notice. I did not change anything to it.
The workshop is a bit dusty, but its enclosure is mostly sealed,and the little dust that gets in through the fan holes, I blow it away with the air compressor (from a distance and gently) every week.

I did not manage to install the windows on an ssd for this pc, so I just cloned the one it had (win xp, sp2? - very old, does not receive an antivirus) on its hdd, and changed the ram memory, and it worked fine. Until now. It just turns off, randomly. No error apears, nothing, sometimes a few times a days, or a few time per hour. Any ideas what could be?

[Neale]

I had the same problem..I found that it was because the CPU heatsink was full of dust. It was difficult to see, and I had to take off the CPU fan to clear it (wooden stick and vacuum cleaner).but that fixed the problem for me. Can't guarantee that this is your problem, but at least it is a fairly easy thing to check and the fix does not cost a lot!

[cropwell]

My thought is that it is thermal shutdown of the CPU. If it isn't dust in the CPU cooler, check that the fan and heatsink are properly attached, I have known certain designs of heatsink mount to fatigue and break with time.

Cheers,

Rob-T

[Radu_Andrei]

Ok. Thank you.

[dazp1976]

Strange that. Hope you get it sorted.
I have issues with CMOS on startup with mine if I switch the power off completely at the plug.
Mines down to the BIOS battery I reckon. Those watch style batteries they use don't fair well in the winter when in the garage. Go totally flat.
Same goes with some of my measuring stuff, I now keep those boxed in the house.

[magicniner]

The way to clean a dusty PC is with the cover off using a vacuum and paintbrush, not with an airline.

[Radu_Andrei]

Ok dasp1976. After the CPU I'll check the battery.
magicniner. Thanks for pointing out the correct way to clean a pc. I'll skip the computer next time I use the airline. I'm not sure I am strong enough to get rid of my air compressor addiction though, as it is my favorite "broom". Don't know why, but it is soooo satisfying to use.

[Radu_Andrei]

Hi.
Regarding the random shut down of the pc, it was not the cpu or the Bios battery, nor the ram memory as I suspected, but the ssd drive and the power supply. Only after replacing both, it worked again.
And yet, after 4 consecutive carvings (apx 6 hours each) done without any kind of problem, on carving number five and six, I've got 2 strange errors.

First error is something that occured once in the past, but went away by its own, and that is that at some point during the finishing cut (ballnose), the z axis goes apx 5mm up (most of the time) or down and continues to cut the rest of the code. If it is up, I can come back to that point and redo the cut and fix it, but if it is down, it just ruins the whole thing. If I remember right, Rob mentioned a lose wire to be a potential cause for these, but I checked all wiring and it is all good. Besides, running the same gcode one more time, it works without this error. Seems more like a mach 3 error, maybe some noise from a misterious source.

Second error is that sometimes, the roughing cut does not fit the finishing cut. Like the first cut, took away to much material in some places. These seemed to get fixed by doing the project again or even as simple as recalculating the toolpath in artcam. Seems an artcam error but I am not sure. Maybe someone knows better.

The only things that changed to the machine is that I finaly figured out how to control the spindle speed via mach3 (pwm). It control the speed fine but when I turn on the whole thing, a relay on the bob goes on and off, like a clock, and this translates as a small rotation of the spindle each time it clicks. Moving the cnc via the pc keyboard when this clicking is on, cause small stalls on all axis. Pressing reset a few times in mach 3 seems to stop the clicking and then everything works great.
It can work without error for many hours or days, and then at some point, while running, I can hear the cnc changing its sound, and moving the z axis 5 mm above and continues to cut. Going back a few hundred or thousand lines and runing again the gcode, it works fine. It is like a temporary source of noise, but I have no clue from what causes it. I could not relate it to weather, or mains power, or time of the day, or gcode.

The only thing that it is clear is that the relay clicking started after setting the pwm spindle speed control, but not at that exact time, a few days later.

Like many other times in the past, I do not know what to do.