Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cor on July 02, 2009, 12:40:24 PM
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Hello people,
I just got a new computer from my brother in law for my homebuild cnc machine, instead of a slow Pentium AMD 750 thingy I now have a Pentium 4 fast thingy :-)
But when I run the axes there is a strange noise from the steppenmotors.... I am sure it has something to do with the switch of the computers, not with the cnc machine itself.
But what can be wrong and is there a solution?
here a small movie with the strange noise:
http://www.youtube.com/watch?v=g5EmKL6HLPo
Here a movie as a reference how it was before (movie was the first test when the machine was finished)
http://www.youtube.com/watch?v=hZtFQbRiX0E
hope someone can help,
many thanks,
Cor
<edit>inserted correct youtube link </edit>
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You posted the "before" link the same as the "after" link. I think the proper "before" link is...
http://www.youtube.com/watch?v=hZtFQbRiX0E&feature=channel
I don't know what your problem is for sure. I can tell you that mine done the same thing, to a lesser degree, but only on one axis. I do believe it started on 2 axis after a short period. How I fixed my problem was....I bought some gecko drivers. They solved the problem. Are your drivers the 3or4 in 1? I'm not saying that the drives are the problem, but if might be worth trying some different ones if possible. Good luck.
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@ Sam: youtube link is updated.
Sam, what dou you mean with the gecko drivers, software drivers or are those the steppenmotor drivers (hardware)? If that's the case, I think it will be easier to switch back to my old computer ......although I like the extra speed.
I tried different modes on the parallelport:
-SPP
-EPP
-ECP
-ECP +EPP
-normal.
but no succes
:-( Cor
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COR,
What make of computer and does it have on-board graphics?
If you can, look at the pulses out of the PP with an oscilloscope. I will bet you have ringing or even multiple spikes on the pulse. What i think happens is, the driver actually sees
two pulses in a hit or miss fashion, and thus it sounds like a mallet / hammer is hitting the stepper motor.
If you can, try adding a different video card. Some computers allow you to jumper the on
board graphics out. That "may" not cure it. Other then that, i don't believe you can do anything about it.
You can use a Smooth Stepper with that computer and not have any problems.
Just check out the pulse before you get into spending any money on anything.
( BTW, i USE GECKO DRIVES AND THEY WILL NOT CURE A SCREWED UP PULSE, NOR ANY SETTING IN WINDOWS THAT I AM AWARE OF )
RICH
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No, they certainly will not, Rich.
If your old computer still runs the motors fine, then that kills the drive theory.
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Did you start with a fresh install of Windows and do the optimization for Mach? Did you do a driver test? If so what were the results? Is your parallel port a 5V port?
You have an issue with the pulse stream coming from your parallel port. If could be that due to other things running Windows can't make smooth pulses, it could also be a hardware limitation of the particular PC. If you have a BOB that expects 5V signals and you have a 3V port that will cause problems as well.
For my money I would use a SmoothStepper.
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It's most likely (pretty much guaranteed) the service interrupt of the mainboard. It's higher than the NMI and cannot be affected by regular code. Also NVidia cards are known to insert milisecond long interrupts which creates pulses inthe pulse train. Nothing you can do about. My parallel port driven taig mill does it, my servo driven smooth stepper router does not. My EMC controlled ill does not because the Linux OS allows a real time core which the amateur OS from Microsoft cannot provide. The problem with a windows based machine is that you cannot possibly achieve real time behavior regardless how hard you try. Only the isolation of the critical timing into external hardware (smooth stepper and alike) provides relieve. Anyone who claims otherwise is into cnc vodoo and might try to sprinkle chicken liver onto his stepper drives to persuade the G-Code Deamons.... haha
Rainer
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hey Guys,
The mainboard is a MSI PM8M-V series:
http://www.msi.com/index.php?func=proddesc&maincat_no=1&prod_no=205 (http://www.msi.com/index.php?func=proddesc&maincat_no=1&prod_no=205)
manual:
http://www.msi.com/index.php?func=downloaddetail&type=manual&maincat_no=1&prod_no=205 (http://www.msi.com/index.php?func=downloaddetail&type=manual&maincat_no=1&prod_no=205)
Installed is a 3ghz intell processor.
@ Rich & Jeff_birt: it has a oboard graphic card, I will try to replace it with an external one. Hope this helps.
I haven't checked the pulse stream, will do that as soon as I am home again next week.
It was a fresh install of windows XP
What do you mean with the optimization with mach?
No clue what the voltage is of the parallelport
@ Lemo: no clue what you're talking about....... all a mystery for me.... what I understand for you , there is no solution , just to go back to my previous (slow) computer.
Which mode needs the parallel port in (SPP,EPP,ECP,ECP +EPP or normal)?
all thanks for the input, I will let you know the outcome at the end of next week.
Cor
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Cor
that noise is a mechanical thump. take a motor loose from the machine and hold it in your hand and spin it.
bill
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@ docltf: and than what? (As said in the first post, this strange noise came a day after I installed a new computer. and is also on all axis. I am 99.99% sure it has only something to do with the new computer and not a mechanical defect) Before I put back the old computer together :-( I want first to explore all possibilities to get this new baby to work well with my cnc machine.
Cor
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Cor
i read your post and i watched your vids. your vids show your machine operating at two differant speeds. your vids show that all three axis thump at the higher speeds with the faster computer. my suggestion is to unmount any motor, hold it in your hand
and operate it with the new computer. see if the motor runs smooth and if thump is still there or it went away. this way you eliminate the mechanical side of it. does the machine miss steps at the higher speed ? if it does not miss steps you could just run it and see what will wear out . run a couple of programs and see how they cut.
bill
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Cor,
Don't spend money on a card wthout looking at the pulse else you may just be wasting your money. See if it's a 5volt output as Jeff noted.
This is interesting because as i write this,my friend just finished putting together a pc and guess what! Yep same thumping sound as yours and i know it all to well. That said.
I went over and did an install, config, etc and his steppers worked fine. Today when he went to use it / next day......bad pulses. I fooled some and reinstalled the driver and the machiine worked fine until i changed an acceleration setting. And back came the bad pulses. Could not fix itno matter what i tried as i have been down this bumpy road before.
So you are not alone, Cor, the only difference is that for myself after manny hours of screwing around i just bought a SS and did away with the problem.
What I have posted before and will say again is that "YOU JUST NEVER KNOW if A PC WILL WORK THESE DAYS".
BTW my friends old slow dead dog 400 MHZ machince ran his machine just fine and no problems ever.
Stay tuned,
RICH
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@docltf: don't worry about the different speeds.The video without the thumbs was the the very very first test with my machine, obviously i run it at extremely low speed. The video I posted was just for reference in the sound. (so you could easily identify the sounds difference). I really can not imagine that 3 steppenmotors can have a defect at the same time, especially when i changed another crucial component in the system. I only suspect it has something to do with the new computer, that's the only thing which make sense.
Although i have to say I know Murphy (from murphy's law) very well...... so... :-) I will keep your solution in the back of my head, but will only check this at a last resort, when nothing helps with the new computer I will first build up my old computer again.
@ Rich: Thanks for the input, I will first check the pulse. I have an older video card still at home, it should be no problem to put that one in.
-How do I check the output V, just put a voltmeter in the hole?
-which mode should the driver be (epp, ecp............)?
- how do I optimize the computer/windows (xp) for mach3.
-my brother in law came with a solution putting in a new/external parallelport instead of the build one......could that be a solution?
thanks people,
Cor
ps unfortunately not at home untill next wednesday, the troubleshooting has to wait :-(
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cOR,
-How do I check the output V, just put a voltmeter in the hole?
Disconnect the PP cable from the computer to the controller.
Put one lead to a step or direction pin and the other lead of the meter to ground. As you jog
the machine you will see the voltage change. You really should look at it with an oscilloscope this way
you see not only the voltage change but also what the pulse signal looks like.
- how do I optimize the computer/windows (xp) for mach3.
look for the file called OPTIMIZE.TXT here is the link:
ftp://ftp.machsupport.com/ in Extra information
I am not sure it will help but worth a try.
--my brother in law came with a solution putting in a new/external parallelport instead of the build one......could that be a solution?
Maybe. If the computer puts out a pulse with a ghost signal / riding on / ringing on the original pulse i doubt
it will do any good. No BOB, filter, etc is going to get rid of it, well not easily anyway.
You may be able to put a different video card in and "maybe" physicaly jumper out the on board video.
I tried different PP cards and that didn't do any good ( you never know ).
You can try fooling with all the computer services but i didn't find anything out of the 50 of or so that had a positive affect.
Again look at your pulse stream as what i / we have may be different. Sorry can't be more specific. Like noted before, you just come a across a pc that puts out a bad pulse and have yet to find some specific cure. I don't want to send you circles.
BTw, my friends old pc puts out 3.3 volts along with a very clean pulse. The new pc puts out a 5 volt signal looked like poop!
One tell tale sign i did find, is that you can run at very slow velocitys like 1 to 4 inches / min, but you can still hear that knocking sound.
Good luck as we will still seek and destroy on our end,! ;)
RICH
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No luck so far :-(
Today I have tested:
-new video card (from the old PC)
-installed windows XP as "standard pc"
-Hyper threading off (in bios)
no change :-(
When I installed mach 3 with windows xp installed as "standard pc" MAch 3 didn't work, it run, but the ax-es remained where they were, also the dro's didn't move/change.
Next to that I tried most of the items described in :"OPTIMIZE.TXT" but also no joy.
I might try a new paralellport instead of the onboard parallel port, but have to go to a computer shop first.
:-(,
Cor
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I am having a similar problem buiding a new machine for a friend. It runs fine with the PC from my own machine but the motors are a bag of spanners with the "new" pc. I have another pc coming and will try that. When I run the driver test with the new pc it first says "pulsing too fast" then says system excellent at end of test. ???
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What are you setting the kernal freq at 25,35,45,60??
When you go from a slow putor to a fast putor you will have to retune all the axis drives.
Just a thought, (;-) TP
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Hi Vmax, both puters are similar spec and both systems set on 25 kernal. ???
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Measure the parallel port voltage, could be too low on the new.
Hood
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Try bumping the kernal freq up to 45 then restart.
(;-) TP
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Changed the CIE (power saving feature) setting in bios to off and driver test is now far better. Max variation now around 8 but mostly a steady straight line. Will connect to machine tomorrow/monday ans report back. Looking hopeful. :) :)
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machine now running smooth with no lost steps. I will have a look at the chipset anyway Riva thanks.