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Mach Discussion => General Mach Discussion => Topic started by: generatorlabs on August 13, 2010, 10:46:02 PM

Title: Switched out my PC and now Mach3 is unhappy
Post by: generatorlabs on August 13, 2010, 10:46:02 PM
I had a very old computer running my Mach setup. It had an Asus based motherboard. Someone donated a fairly decent looking Dell to me that had much more horsepower than my old Asus. It is a Dell Dimension 4600. I did a fresh install of XP on it then immediately installed Mach3. After setting up the pins/motors I get the most horrible noise from my steppers when moving any axis. The motors are stuttering and binding. I plugged my rig back into the Asus based machine and it works well. I even copied the setup XML file from the Asus to the Dell to make sure all the settings were valid. I checked BIOS and set port to EPP. Now I have run out of ideas and need some guidance please. Anyone out there experience this phenomenon on a Dell Precision?
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 14, 2010, 04:55:01 AM
Try the optimisation steps outlined on the downloads page and see if that helps.
Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: generatorlabs on August 14, 2010, 09:57:04 PM
I did the opto procedure with another fresh install of windows Xp home and the Dell PC acted exactly the same. The motors sound very bad, almost as though they are straining. The max speed cannot be set above a crawl of the motors crash and buzz in one spot. It almost sounds like the direction pins are not remaining on long enough or the pulses are too short. I tried setting the pulse duration to 5 and no change. Is the Dell Precision parallel port compatible?
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: budman68 on August 14, 2010, 10:02:08 PM
So you've disabled ACPI and it had no effect at all?

Thanks,
Dave
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 15, 2010, 02:32:37 AM
Some computers just will not run Mach via the parallel port, I believe it may have been a Dell that Rich had and tried just about everything and still couldnt get it to work. His had, if I remember, a tick tick sound as the motors rotated, is yours similar?

Few things you could try,
If its onboard graphics get an addon graphics card.
Try a PCI parallel port

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: generatorlabs on August 15, 2010, 10:11:03 AM
Yeah ACPI is not enabled. This was very evident when I went to shut the PC down and now it gives me the message "It Is Now Safe To Turn Off Your Machine". When I did the previous frresh install of XP Home without disabling ACPI it would shut down all the way.

This is best way that I can describe the sound. Imaging a stepper making attempting to make a full step but at the last few microseconds of its travel I try to reverse direction. Almost like that saying "take two steps forward and one step back". When the motors are crawling they appear to work but do not make that sweet low pitch whining noise. If you ramp the speed up to even midrange there is no nice whining but some serious stuttering. This is not even half the rated speed of a stepper. On my other computer with the exact same settings the motors purr along like little kittens. On the Dell it sounds like a bunch of bulldogs fighting.

I do not use the onboard video. It is disabled and I have a beefy ATI AGP card in there.

So my alternatives are getting a new PCI Parallel Port? Is there a USB solution that will work? Any recommended, known foolproof PCI cards that I should be looking for?

As a longshot is there any driver chip on that main board that I could desolder and install a better one or is that functionality built into the southbridge chipset?

Thanks for the help.




Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 15, 2010, 10:16:12 AM
First thing is if you have not already looked, see what the driver test looks like.

As for USB then there is the SmoothStepper, it does the pulsing so should solve your bad pulsing issues.There are a few things such as backlash comp that the SS does not do yet so be aware of that if you choose to go down that road.
Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: docltf on August 16, 2010, 11:36:55 AM
when you change to standard pc that is what happens to the shutdown with xp.also you cant go back to apci without reinstalling windows.
have you played with the pulse width for the motors? have you tried sherlin mode?

bill
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 18, 2010, 08:37:22 AM
It may well be the built in parallel port. The computer I am using now has similar behavior if the built in parallel port is used at anything over 25K driver speed.

A MACH3 compatible dual PCI parallel port solved the issue completley for me. I posted here a while back the exact card that I am using, source for the card, where to get the drivers, etc. Just do a search and it should show up.  My computer tops out at 86K pulse rate, but the card seems to handle it fine. I run stable at 75k.

The card as I recall is something like $15 or less.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: generatorlabs on August 20, 2010, 09:07:40 AM
Well I have concluded that the Dell printer port is real crap. I decided to take the computer in my study and swap it with the Dell. I will now use it as my controller. That PC is built around another Asus motherboard. Without having to do any optimization that machine runs my steppers flawlessly. This is not an endorsement for Asus but lets face it this will be the third Asus machine I have moved Mach to and they always run right. Sorry Dell but you lost my future business.

Thank you to all for your input but I think I got this problem solved now.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 20, 2010, 05:48:48 PM
FWIW, I just today installed a new computer on my CNC mill that happens to have an ASUS mother board also. The old computer got a gremlin in it and was doing very bizarre things.

The new computer is a budget build using an ASUS motherboard P5G41-M LX2 with an Intel E6500 dual core processor. I re-used the memory, PCI parallel port card, hard drives, case, etc. from the old computer. The new computer is getting along fine so far with Mach3 and is running stable at the full 100k pulse speed.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: generatorlabs on August 20, 2010, 07:04:12 PM
I am glad you had good luck with that Asus build.

On a side note I notice many folks talking about running at 100K. I am assuming this is the kernal speed. I am running at 35k. To be honest I don't know the advantages of running any higher or lower. Could someone let me know what happens if I bump it up? Do you need a monster processor to run at 100K? What are the advantages?
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 20, 2010, 08:27:07 PM
If you dont need to run any faster than 35KHz for your setup then dont as it will not give you any benefits and may actually cause issues. The only reason to use a faster kernel speed is if you cant get the required rapids from the kernel you are at now. With a stepper system 45KHz would likely be the normal max you would need, a servo system may, depending on encoder count, require faster to achieve its potential. Although its been quite a few years since I have used the parallel port with Mach I never had a computer that was 100% happy at 100KHz.

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 21, 2010, 09:17:04 AM
It is all in the numbers.

Figure out the RPM you want to run the motors and the numbers of steps required to achive that , for example (using round numbers);

Steppers  1,000 RPM x 200 steps per rev = 200,000 pulses (per minute) which is only about 3,300 pulses per second, so 25,000 kernel speed would be plenty, however, if you have 10 micro step drive, suddenly you need 33,000 pulses.

Servo     4,000 RPM x 8000 steps per rev = 32,000,000 pulses per minute which is 53,300 steps per second, so you yound need to run 60k kernel speed to get full rpm.

Alternatives to full kernel speed in Mach are pulse mulripliers in the drives or a pulse gerenator independent to Mach3 such as Smoothstepper or Kflop.

A few years ago is a long time in computer history. I just put together what I would call a 'budget' build using 2 gerations out-of-date technology (socket 775) and it is running Mach at 100k (so far). A good test of headroom is to open the task manager and set it on performance and then drag it rapidly around the screen as Mach is running a program.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: docltf on August 21, 2010, 09:33:01 AM
Simpson36

that is one of the best descriptions of the pulse and a real good quick test.
the people that write the mach manual should use it.

bill
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 21, 2010, 11:45:42 AM
Thanks docltf

If they correct my rather significant boo-boo in the math (what's an order of magnitude between friends, eh?) then they are certainly free to use it.

The correct number of pulses per second for the servo example is 533,000 . . . slightly above Mach's maximum kernel speed.  ::)

Even if one can run Mach at 100k, a 6x multiplier would still be needed in that example to get max RPM. This is  doable with many, if not most, servo drives . .  and also explains why I have to use multipliers . . .  

Another example for a realistic servo setup at the hobby level would be:

3,000 RPM x 2000 steps per rev (500 line encoder in quadrature) = 6,000,000 steps per minute which coincidentally is 100,000 per second . .  if I got it right this time  :-[
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 21, 2010, 12:17:15 PM
Glad you added the "(so far)" bit ;D
It is like you say that 2 yrs is a long time but I also thought mine was fine,  occasionally however it would get wee glitches and dropping the kernel down to 45KHz cured these problems. Worth noting was that 65 and 75k ran like crap for some reason and was apparent from the start that things were not right on these kernels.

As for electronic gearing, some like it others dont, I am in the latter camp. Real world it may not make a big difference buit I just didnt like the jerky motion on a clock (DTI) when I commanded a very slow move with an electronic gearing of 6 or so, put it to none and it was silky smooth :) Maybe that was down to my tuning or possibly even the way my drives deal with things but as Greg had sent me a test version of the SS plugin for  threading  I never really bothered looking into it further.
Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: docltf on August 21, 2010, 03:40:13 PM
damn the math,the general direction of the concept was well put.

i am with you Hood,get the resolution done with the mechanical parts.that way you can put the motors on a full step.


bill
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 21, 2010, 03:40:49 PM
Glad you added the "(so far)" bit ;D
It is like you say that 2 yrs is a long time but I also thought mine was fine,  occasionally however it would get wee glitches and dropping the kernel down to 45KHz cured these problems. Worth noting was that 65 and 75k ran like crap for some reason and was apparent from the start that things were not right on these kernels.
My last computer was as you describe. I could only run about 45 with the 2.6ghz processor. I switched only the processor to a 3.2ghz with hyperthreading and then I could run 75k. If I set it to 100k, it would only actually kick out 89k which I found odd. I would have though it would either work or not, but it was running as a reduced speed which made me nervous so I backed it off to 75, but it ran fine there . . . uh  . .  well , until the RPM readout went psyco on it. The new computer I just put in has a dual processor @ 2.93 (or there about) and dual channel memory so it is far more powerfull than the old one and SO FAR it is running at 100k no problem. I will leave it there for all of my testing, but probably drop it back to 75 if I cut anything expensive . .  

Quote
As for electronic gearing, some like it others dont, I am in the latter camp. Real world it may not make a big difference buit I just didnt like the jerky motion on a clock (DTI) when I commanded a very slow move with an electronic gearing of 6 or so, put it to none and it was silky smooth :)

There may be other factors, but one for certain is the way the drive handles the process. The Mistubishi MR-C series also is not very happy with multipliers. However, I would put a $100 bill on the bench and give it to you if you could tell the difference between a 6x an 0x multiplier on a Granite drive running a DC brush motor. Likewise the Mistubishi J2S series is smooth as silk running a HUGE multiplier . . .  the thing has outrageous resolution. "An up to 500kpps high-speed pulse train is used to control the speed and direction of a motor and execute precision positioning of 131072 pulses/rev resolution."The only time I have ever actually recommended the Smoothstepper was to use with Dugongs since that drive runs pretty badly with multipliers, especially at low speeds as you pointed out.  Curiously, the little brother Whale drive is fine with multipliers active. I still run those on my X and Y axis at 5x or 6x.  Mind you that when set at 1:1 the Dugong is a killer. Smooth and very powerfull with the ability to stop on a dime.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 21, 2010, 04:51:15 PM
I couldnt physically see the jerky motion it was only if I commanded a move at something like 1mm/min and had the DTI against the axis, you could see the needle step round but with it at 1:1 it was smooth motion. As said real world it would likely not be an issue but if I know its there it bugs me ;D
 The encoders that I have on the spindle motors on both lathe and beaver mill are what they call intelligent encoders and you can have, if I recall correctly,  the drive interpolate up to 2 million counts per rev(8million pulses per revolution ::)  ), thats even beyond SmoothStepper territory ;D I was happy just at the base 1024 x 4 for a spindle.

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 23, 2010, 07:04:03 AM
. . .  are what they call intelligent encoders and you can have, if I recall correctly,  the drive interpolate up to 2 million counts per rev(8million pulses per revolution ::)  ), thats even beyond SmoothStepper territory ;D I was happy just at the base 1024 x 4 for a spindle.

I had 1800x4 on the 4th axis (good for division by 360) with the DC brush servo. With both the Dugong drive and the Granite drive, it makes no noise when holding still.

Currently I am working with two different series Mitsubishi AC servo drives now, the larger of which I *think* is similar to the Alan Bradley 3000 series . . maybe. The little Mitsu MR-C has only 4000 pulses per rev and 'sings' (to quote Gecko) when holding, presumably due to bouncing back and forth between adjacent pulses. This is very noticeable on the MR-C, but with the J2S drive, while it still sings, it is almost inaudible perhaps due to a much higher frequency and much smaller step (131,000 steps). That servo motor is also brand new so that may also have some contribution to the far lower noise level.

So, my question is; does the Allan Bradly drive/motor behave similarly, i.e. do they 'sing' or make any noise when holding still?
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 23, 2010, 07:09:30 AM
No, if tuned correctly they have very little noise and if you monitor the encoder in the software it does not vary at all.

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 23, 2010, 07:31:28 AM
No, if tuned correctly they have very little noise and if you monitor the encoder in the software it does not vary at all.

Thx. I have the mistu software, but have not used it yet, however the J2S series drive has a 4 digit DRO that can be set to display just about any data in real time, including encoder feedback, so I can monitor that without the software. The J2S is the first servo drive I have used that I can say I am completely satisfied with . . . so far  ;) . I would describe the J2S similarly to how you rate the Allan Bradley; 'very little noise'.

I will be needing more AC servos so I am just collecting info on the options.  The Mistubishi J3 is a freak! Too new though, and not readily avaialble from the junkyards yet.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 23, 2010, 07:54:55 AM
I had thought about buying some Yaskawas that I saw for a decent price but decide I would just stick with what I know and like. I now have at least one spare drive for all that I use, even a spare for the 22KW drive thats on the Lathes spindle :)
The older Allen Bradley drives I didnt rate quite so much but they were still ok but lacked some I/O that the newer ones have.

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 23, 2010, 08:36:28 AM
I had thought about buying some Yaskawas that I saw for a decent price but decide I would just stick with what I know and like. I now have at least one spare drive for all that I use, even a spare for the 22KW drive thats on the Lathes spindle :)
You are wise, ObeeWan!  Spares is a definate consideration. I don't want to end up like I did with the DC servos having a different brand on every axis. Pretty expensive to have spares that way! I have been paying attention to 'general availability' as an important parameter since I can't aford to buy a bunch of new drives at this level. Mitsubishi J2S are adequate for my needs and nearly always available for reasonable prices from 200watt to 750watt, which is the range I am interested in at the moment.

Quote
The older Allen Bradley drives I didnt rate quite so much but they were still ok but lacked some I/O that the newer ones have.
Again, I have to agree that the I/O is really a huge difference between the 'hobby' and 'industrial' levels. Lack of same was a real frustration with the inexpensive DC servo drives I was trying to use previously. 

Question; what are the series of the 'older' and 'newer' models of the Allen Bradleys you are using?
[/quote]
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 23, 2010, 08:55:07 AM
The older drives still have more I/O and more configurable than the normal hobby type drives but just not as good as the later ones,  then again compared to the hobby drives they are a lot more expensive new so its understandable.
The older drives are Allen Bradley DDM or Giddings and Lewis DSM
The newer drives are Allen Bradley DSD or Giddings and Lewis DSA

Software  required for DDM/DSM is UltraMaster/DSMPro
Software  required for DSD/DSA is UltraWare/DSAPro
I have both if you ever require just shout.

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 23, 2010, 07:33:44 PM
Thanks!

Back on topic, I am starting to use my new computer and I found some interesting behavior that I want to contribute to the kernel speed discussion. On my new setup, I can run 100K kernel thru the first BOB, but not thru the second. I have not seen this mentined before in speed discussions and it really did not occur to me until today when I was trying to run the 100K stream thru the second BOB to the 4th axis.

In this case the drive has a 4 place LED that can display (among other stuff) the pulse frequency coming into the drive. On the X axis testing (BOB number one) it was showing the 100k steady. Now I have it on the 4th axis on BOB number2 and it is shows unstable anything over 60k.

Bottom line is that the computer, which is always suspect number one, is not necessarily always the culprit.  The BOB has to be able to pass the stream thru it's optos and other circuits at that speed as well.  Seems obvious now, but it never occurred to me before.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 24, 2010, 02:18:46 AM
There is that but it couldnt be the case for me as its now happy at much more via the SmoothStepper.
Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 30, 2010, 09:51:09 AM
There is that but it couldnt be the case for me as its now happy at much more via the SmoothStepper.
Hood

Since, as I understand it, the BOB is downstream of the smoothstepper, wouldn't the problem still apply?

Incidentally, I have purchased a smoothstepper, so I will be better able to comment on it after I have some 'hands on' time with it . . . which may not be any time soon, but eventually I will play with it.
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 30, 2010, 09:56:37 AM
Since, as I understand it, the BOB is downstream of the smoothstepper, wouldn't the problem still apply?

Not sure I read your post correctly then. What I thought you were meaning was some BOB's couldn't pass the higher frequency, if that was what you meant then the PC then SS then BOB would surely suffer the same way as the PC then PP then BOB?

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: simpson36 on August 30, 2010, 10:18:52 AM
Not sure I read your post correctly then. What I thought you were meaning was some BOB's couldn't pass the higher frequency, if that was what you meant then the PC then SS then BOB would surely suffer the same way as the PC then PP then BOB?

Exactly. If a particular BOB can only pass say 86K pulse speed, then it would impose that limitation on both a PC, a SS, or anything that was generating a pulse stream.

I did a quick perusal of CNC4PC site and they have made a point of stating that one of their upper end boards has been upgraded to handle a 150KHz pulse stream thru the optos. The obvious conclusion there is that at one time the 'speed limit' was lower.

Of particular interest is that they have a BOB specifically designed to work with the SS via direct plug compatibility with the SS and specifically sporting a 1MHz pulse stream capability.  :o

So with one board having been ungraded to 150KHz and their flagship board boasting 1MHz, it is obvious that the capabilities vary widely. My CNC4PC product is their Gecko specific model with NO optos on the outputs. This may explain why it can handle a 100KHz stream while my second BOB cannot.

Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 30, 2010, 11:19:22 AM
Ok I see where the confusion is now, I was saying the BOB in my case could not have been the problem running the PP at 100KHz as I now use it with the SS and you were thinking I was saying something different.
In any case both my BOBs are quite happy at the 533KHz that I once had the lathe running at, it was me that wasn't happy as it  was frightening ;D

Hood
Title: Re: Switched out my PC and now Mach3 is unhappy
Post by: Hood on August 30, 2010, 01:54:37 PM
Just had a look, I knew the PMDX 122 was capable of 1MHz but was unsure of the Acustep, seems it uses 10MHz optos and the manual states >5MHz Opto Isolation speed.
Hood