[blighty]

hi all,

seem to have a problem with a Boxford 240 cnc retro.

ill try and keep this short.......

got this lathe all kited out to run with mach3, still had the original steppers on it. every now and then the X and Z stepper would stall. i played around with a few things and finally it stopped stalling. about a year later they started stalling again. thought i would fit new steppers and a new higher voltage power supply to run them. when all done the X and Z are running much better and no stalling.

it was then decided to fit a new pc. Mach 3 was loaded up on the new pc with the old pc's mach3 profile. hooked it all up, everything worked fine........ but now the steppers stall worse then before. put the old pc back on and all is fine.


as far as i can tell (in Mach3) everything is the same and i didn't need to touch anything in the lathe....... it's just a new pc.

any help would be much appreciated.

[LongRat]

How did the new PC look on the Mach3 drivertest? Might be that it just can't produce a clean pulse train.

[blighty]

did the driver test on the new pc.... showed little spikes. i know the old pc did as well.

ill take a screen shot of both and post them.

[ger21]

What kind of processor is in the new PC?

[pippin88]

I used to have random stalls and lost steps when moving multiple axes under Mach, never could work out why. Moved to LinuxCNC, no problems at same speeds

[blighty]

thx for the replies guys.....

the old pc was a 2.8 with 500mb ram.

new pc is a 3.6 duel core with 3.5gig ram.

i have up loaded some pics and a vid of what its doing.


fist pic is the driver test from the old pc, second is the new pc...... to me the new one looks better,
Attachment 229688
Attachment 229690

pic below is general setting and motor tuning page.

Attachment 229692
Attachment 229694

and last a little vid.



as i said, apart from the pc i have changed nothing else and all settings are the same. if i put the old pc back on all is well.

you may be thinking "why not just put the old pc back on".......... i would, but it's not my lathe.

[ger21]

Go into the bios and and disable C1E or EIST, and see if it helps. This often fixes issues with dual core CPU's.

Imo, the driver test doesn't really tell you to much. If you have a really bad PC that barely runs motors at all, then the driver test will tell you what you already know.
But you can get a decent looking driver test and still have issues, even with the "System Excellent" message.

[blighty]

thx ger21,


i'll have to give that a go latter........ off to work :-(

[wizard]

Of course you don't want to hear this now but it is always a good idea to verify that someone else has had success with a PC before running any G-code interpreter on it. Some PC just have issues with generating the pulse trains required. This is one reason why everybody and their brother is moving to things like Smooth Stepper on PC's running Mach. These pulse train generators take the PC variable out of the equation.

You can go into the BIOS and try disabling things you know you don't nee, but if this problem is coming from system management interrupts you may not be able to do anything about it. Sometimes using a discreet video card can help if this is a machine with integrated graphics. I'm actually thinking the video issue has been resolved in the latest hardware and drivers, that however may be a LinuxCNC bit of information.

[blighty]

had a chance to have a look at the bios. couldn't find anything in there about (C1E or EIST), but i did find something that urns off one of the cores.this i did and still no joy :-(

did notice one thing when the steppers stalled. at the point they stall they don't just stop and make the chattering noise. they start turn in the opposite direction.

Wizard.....

was thinking about getting a smooth stepper for when i give my mill an overhaul. i know they did have some problems when they first came out and patches where far and few between.

do you have a smooth stepper? if so, have you had any problems.

[Fastest1]

blighty, I have both the USB and Ethernet versions of the SS. They are both good in their own ways. There have been teething problems with both models though the Ethernet version is the most dependable and hold the most promise in the future.

After having assembled a few different machines with various controllers, drivers and PC's. The computer does play a pretty big role IMO, the speed and incredible storage capacity doesnt secure good operation necessarily. I am not sure of what does to tell you the truth. I have a video of my G0704 going incredible speeds (331 ipm). killed that computer and am running a different computer and have a hard time hitting 80 ipm without a major stall. Though I havent pursued that issue with any effort. Not machining much and not above 80 ipm anyway it hasnt been a problem but just knowing the mill should run much faster bothers me. An ESS made no change in that.

[SCzEngrgGroup]

blighty, I have both the USB and Ethernet versions of the SS. They are both good in their own ways. There have been teething problems with both models though the Ethernet version is the most dependable and hold the most promise in the future.

After having assembled a few different machines with various controllers, drivers and PC's. The computer does play a pretty big role IMO, the speed and incredible storage capacity doesnt secure good operation necessarily. I am not sure of what does to tell you the truth. I have a video of my G0704 going incredible speeds (331 ipm). killed that computer and am running a different computer and have a hard time hitting 80 ipm without a major stall. Though I havent pursued that issue with any effort. Not machining much and not above 80 ipm anyway it hasnt been a problem but just knowing the mill should run much faster bothers me. An ESS made no change in that.

CPU speed and memory are virtually non-issues. I ran for many years with a ancient 533MHz PC with only 512M of RAM. It was running my servo-driven knee mill at 350 IPM. Never a single problem that could be attributed to PC performance.

Regards,
Ray L.

[blighty]

think your all right :-)

it may just be the pc. when i did my mill i got a pc plunged it all together and it worked...... in the end. when a mate of mine did his, he tried 3 different pc's before he found one that worked.

my cnc mill at the moment will do about 300ipm but is set to 177ipm. the mill could do with a overhaul. just thought i would get an SS (and a bob, as im not running one) and do it all good and proper.
was thinking would it be worth getting a SS or just leave it as is......... should still get a bob.

[Fastest1]

I agree with Ray again. The computer that gave me the best performance on that machine was an old re purposed computer with no enviable specs to speak of.

[Fastest1]

Not knocking the ESS or USB SS just saying it wont rectify a bad computer issue.

[blighty]

Not knocking the ESS or USB SS just saying it wont rectify a bad computer issue.

so if that the case, whats the point of them?

as i thought the problems is sending pulses through the PP with no buffer. i.e strait in strait out kind of thing. so if the pc does have a fit for a split second the stepper go ape. (i may not of used the correct terminology, but i hope you get the point)

from what i gather, the pc sends the pulses to the SS that SS saves them up (buffs) and when it has enough it then starts sending them on the the bob, drivers then steppers. so if the pc does "go off on one" nothing will happen as the pulses from the SS will not be interrupted. again (i may not of used the correct terminology, but i hope you get the point)

[Fastest1]

I started becoming familiar with them just because the parallel port is a thing of the past. The sooner we face the problems, the sooner our problems are solved.

[ger21]

Not knocking the ESS or USB SS just saying it wont rectify a bad computer issue.

If the only issue is that the PC won't run a machine through the parallel port, then yes, it will. The Smoothstepper takes the place of Mach3's parallel port driver, which is what causes issues in different PC's. Without the parallel port driver, Mach3 is just another windows program, that should run fine on any PC.
You can run Mach3 on windows 8 with a Smoothstepper, which is impossible to do with the parallel port driver.

[neilw20]

1. Some PCs have marginal output levels that may give good pulses to the driver as speed increases.
2. If the PC uses DMA interrupts, these have priority over low level stuff the Mach3 driver uses.
3. Even IDE to a CDROM can cause problems. Make sure the HD is the master, not the slave.
Study the attached. Well written by Art. Looks a little blank. It is a PDF

[SCzEngrgGroup]

so if that the case, whats the point of them?

as i thought the problems is sending pulses through the PP with no buffer. i.e strait in strait out kind of thing. so if the pc does have a fit for a split second the stepper go ape. (i may not of used the correct terminology, but i hope you get the point)

from what i gather, the pc sends the pulses to the SS that SS saves them up (buffs) and when it has enough it then starts sending them on the the bob, drivers then steppers. so if the pc does "go off on one" nothing will happen as the pulses from the SS will not be interrupted. again (i may not of used the correct terminology, but i hope you get the point)

Ummm..... Not really. Mach3 sends the SS periodic messages containing high-level motion commands - basically time-stamped position and velocity information - and the SS generates the Step/Dir pulses and other functions directly in hardware, and gives periodic status reports back to Mach3, so they remain in-sync. Mach3 remains responsible for all trajectory planning, but the SS handles all of the execution, making the work Mach3 still has to do FAR less time-critical. Because the SS generates the Step/Dir timing in hardware, there is several orders of magnitude less jitter in the timing.

Regards,
Ray L.