Re: [Emc-users] Following error
Richard I am attempting to tune my machine, running rutex drives and emc2. I command a drive to move 8 inches one direction reverse and return to zero. G1 X-8.0 F10 G1 x0.0 F10. When I test with a dial indicator if the machine returned I see that I over traveled .005. I retuned the drive and increased the i value and adjusted p and d to reflect the increased i. I rerun my 8 inch test and find I returned to zero. I then run the same test but with twenty inches of motion and find myself 2 thousands short. Just to see what would happen I increased my feed rate from 10 to 15ipm. Suddenly the machine returns to zero. I increased the feed to 30ipm and I overshoot. It appears that I have a velocity dependent situation. You might like to investigate electrical noise. Speed will obviously cause steppers to loose steps but I do not see how the servos would suffer. I have only used the older Rutex drives but they allowed a massive 32k count following error and more importantly would fault out if it was exceeded so you never got lost steps that you did not know about (only following error!) Noise on the encoder signals will confuse the drive about where the motor actually is and, of course, noise on the step signal will alter the requested steps. You talk in terms of overshoot and undershoot but you do not really know which direction of motion (or both) causes the errors so whether you are looking for lost or gained steps. Can you use a setting bar to measure a one-way journey. John Prentice ps Out of interest, what was the reason for the sudden death you had or how did you fix it?- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Following error
The settings in EMC's ini will not make much difference because EMC has no feedback about real position. Step-and-direction is out only and assumes that the systems out there are able to follow accurately. The Rutex PID loop tunes like nothing else I've used. You will need to increase P, but that's not all. Increasing P will narrow the resting position of the motor. Think of this as a dial indicator or caliper sitting so that commanded position is in the center of the space between jaws. P then is the distance between the jaws. Make the jaws closer together and you will have less error in final resting position. The problem here is that you've got to increase D along with P in order to get the Rutex to respond. Then with more D you need more I to calm it. This is a very dynamic process. Hint. Make only one change at a time and write each change down with a better, same, worse evaluation for both accuracy and palsey. You'll have to run P to where the motor will not settle down at all and then increase I and D. If you have a way to hand crank the axis while the motor is running it will help you feel the stiffness of the system. Rayh On Mon, 2007-01-08 at 10:05 +0200, Anders Wallin wrote: It appears that I have a velocity dependent situation. I honestly have little background in PID tuning, is this a drive tuning issue or is this an EMC config issue? I am using the sample_inch.ini config and have only changed the steps per inch, reduced the max acceleration, and max velocity to reflect my machine. most likely this is a tuning issue within the Rutex drive. If I understand correctly you are driving the rutex with step/dir signals from the parallell port. EMC will have no idea of where your machine is, it relies on the drive to close the loop. So, your following error setting should be in the rutex drive. If the following error limit is set too high the behavior you describe would be allowed. Try reducing the allowed following error in the rutex drive and then maybe re-tuning it. AW - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] Parport stepper setup
Hello, I have been investigating using EMC2 and some stepper motors to a small milling machine. I have a cloudy area of understanding around driving the stepper motors. As usual I am trying to do it on the cheap :-) and hence would like to develop my own stepper driver. I am hoping someone can provide some direction so that I don't fall off any cliffs. So far I believe there is two ways to generate an amplified stepper signal (half, full etc). Method 1 Using the parport config to send a step signal and a direction signal for each axis. Run these signals into a stepper driver chip which is configured for the stepper phase that I require. This method should leave a few extra pins on my parallel port to play with later. Method 2 Use the functionality of the stepgen module to perform the required stepper phase for each axis. Amplify each signal into the motor. This method will use up more parallel port pins depending on the amount of coils in the stepper that I purchase, I may even need another port if 5 phases is required. Are both methods possible? Which method is the most common or gives the best result? I also intend to opto isolate the signals coming from the parallel port to protect my motherboard, is there any unforeseen problems doing this? Cole - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport stepper setup
Yes. On 1/8/07, Colin [EMAIL PROTECTED] wrote: Hello, I have been investigating using EMC2 and some stepper motors to a small milling machine. I have a cloudy area of understanding around driving the stepper motors. As usual I am trying to do it on the cheap J and hence would like to develop my own stepper driver. I am hoping someone can provide some direction so that I don't fall off any cliffs. So far I believe there is two ways to generate an amplified stepper signal (half, full etc). Method 1 Using the parport config to send a step signal and a direction signal for each axis. Run these signals into a stepper driver chip which is configured for the stepper phase that I require. This method should leave a few extra pins on my parallel port to play with later. Method 2 Use the functionality of the stepgen module to perform the required stepper phase for each axis. Amplify each signal into the motor. This method will use up more parallel port pins depending on the amount of coils in the stepper that I purchase, I may even need another port if 5 phases is required. Are both methods possible? Which method is the most common or gives the best result? I also intend to opto isolate the signals coming from the parallel port to protect my motherboard, is there any unforeseen problems doing this? Cole - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] drive refuses to move SOLUTION!
I was able to correct my drive problems by connecting the Rutex to a windows box, writing down my tune and resetting the drive to the factory values. I then retuned the drive with my values from before. Connected EMC and it runs. I would not call this a solution, but it did solve the problem I was experiencing. All I can assume is that the drive and windows had some sort of communication error when it saved the eprom, when the drive was connected to the windows box the on board setting must be ignored, when the drive is in a stand alone setting the eprom must of been junk and the drive inoperable. Thanks for all the ideas. richard harris [EMAIL PROTECTED] wrote: The drive does not give an error message, the drive refuses to move. I have checked my wires, I use 2 different DB15 cables, one for tuning one for emc. The emc cable only provides power. The setup was running all day, then suddenly nothing. Chris Morley [EMAIL PROTECTED] wrote: Hey Richard. Does axis give an error or does the motore just not move? Chris Morley - Your Space. Your Friends. Your Stories. Share your world with Windows Live Spaces. - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport stepper setup
Cole, I've built my own setup using EMC to drive minimill - works great - many thanks to all the people involved with the development of EMC!! Here what I did: Built a simple power supply - 10A @35V Transformer + Bridge rectifier + 2 x 22000 uF capacitors - no problems (see http://pminmo.com/simpleps.htm) Built my own stepper motor driver cards using the L297 / L298 running as a bipolar half stepped drive (check out st.com for the datasheet this gives a circuit linking the L297 and L298) - no problems Built an optoisolator card - had some problems here since EMC pulses are very short in the end I used 6N137 optos and the information here http://www.freescale.com/files/microcontrollers/doc/app_note/AN2342.pdf to build a 12 channel output only card i.e. step and direction for channels A, B, C, X, Y, Z. The card so built works really well - make sure you have truly isolated power supplies for the CNC and PC side. Purchased some low cost stepper motors (make sure you get the wiring diagram) and connected the X and Y directly to the table axes. For the Z axis I found a ball screw on eBay attached it to the mill by means of a purposed made plate with thrust bearings. The Z motor drives the ball screws by means of a 9mm timing belt. Try and drive your axes directly as this reduce backlash and since the steppers produce high torque at low revs so using belts and pulleys to increase torque is counter productive as the stepper must rev higher to get the required traverse speed - Initially I drove the X and Y axes using 2:1 reduction - this has now been junked and for direct drive via Oldham couplings. Sat down and fiddled with Linux(dark world of pain for me) and EMC (confusing initially but loads of help via this forum - it starts to make a lot more sense when you finally see a motor turn!!) and finally got the system going. It been running for around six months now and, touch wood, has operated faultlessly. The above development took me around 18 months in between the wife, babies, shopping, decorating ... Hope this is of some use. Regards Andy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Colin Sent: 08 January 2007 13:49 To: emc-users@lists.sourceforge.net Subject: [Emc-users] Parport stepper setup Hello, I have been investigating using EMC2 and some stepper motors to a small milling machine. I have a cloudy area of understanding around driving the stepper motors. As usual I am trying to do it on the cheap :-) and hence would like to develop my own stepper driver. I am hoping someone can provide some direction so that I don't fall off any cliffs. So far I believe there is two ways to generate an amplified stepper signal (half, full etc). Method 1 Using the parport config to send a step signal and a direction signal for each axis. Run these signals into a stepper driver chip which is configured for the stepper phase that I require. This method should leave a few extra pins on my parallel port to play with later. Method 2 Use the functionality of the stepgen module to perform the required stepper phase for each axis. Amplify each signal into the motor. This method will use up more parallel port pins depending on the amount of coils in the stepper that I purchase, I may even need another port if 5 phases is required. Are both methods possible? Which method is the most common or gives the best result? I also intend to opto isolate the signals coming from the parallel port to protect my motherboard, is there any unforeseen problems doing this? Cole - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport stepper setup
colin wrote: Method 1 Using the parport config to send a step signal and a direction signal for each axis. Run these signals into a stepper driver chip which is configured for the stepper phase that I require. This method should leave a few extra pins on my parallel port to play with later. this is the way most parallel port EMC setups are done. Method 2 Use the functionality of the stepgen module to perform the required stepper phase for each axis. Amplify each signal into the motor. This method will use up more parallel port pins depending on the amount of coils in the stepper that I purchase, I may even need another port if 5 phases is required. i have a small mill that works like this. it requires a small shim driver to generate the correct phases at the correct times for my motors. i'd say, if you're still choosing your hardware, to choose something with step and direction signals. and, as someone else said, consider buying something off-the-shelf that's already known to be supported by EMC. (of course, your choice will be dictated by how much you want to spend, and by how much time you want to spend using your mill vs building your mill. sometimes building is more fun than using. :-) paul =- paul fox, [EMAIL PROTECTED] (arlington, ma, where it's 38.5 degrees) - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport stepper setup
hmm, but something with step and direction signals has only one half of the maximum step pulses per second than a quadrature output has. Therefore my design takes quadrature output of EMC, puts it into QENC module of PIC18F4431 (The one I badly wanted back in 2002/2003) and that one does output microstepped - pure analog waveforms, the current regulator is boosted L165 as per datasheet, the supply voltage is provided by two 16V 100W modules SMPS (~30USD each.) The motors are a bit expensive Shinano Kenshi SST83D ... but still the fastest steppers from all I have searched in many years of research, and powerful.. ~10Nm, 160W in high revolutions. A bit more heat generated than it would be with VC CS/S SMPS, but I think it is not worth all that complication. On 1/8/07, Paul Fox [EMAIL PROTECTED] wrote: colin wrote: Method 1 Using the parport config to send a step signal and a direction signal for each axis. Run these signals into a stepper driver chip which is configured for the stepper phase that I require. This method should leave a few extra pins on my parallel port to play with later. this is the way most parallel port EMC setups are done. Method 2 Use the functionality of the stepgen module to perform the required stepper phase for each axis. Amplify each signal into the motor. This method will use up more parallel port pins depending on the amount of coils in the stepper that I purchase, I may even need another port if 5 phases is required. i have a small mill that works like this. it requires a small shim driver to generate the correct phases at the correct times for my motors. i'd say, if you're still choosing your hardware, to choose something with step and direction signals. and, as someone else said, consider buying something off-the-shelf that's already known to be supported by EMC. (of course, your choice will be dictated by how much you want to spend, and by how much time you want to spend using your mill vs building your mill. sometimes building is more fun than using. :-) paul =- paul fox, [EMAIL PROTECTED] (arlington, ma, where it's 38.5 degrees) - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] Parport stepper setup
Hi Andy Thanks for the great report. Glad to hear that you got it working. Rayh On Mon, 2007-01-08 at 21:43 +, Andy Ibbotson wrote: Cole, I’ve built my own setup using EMC to drive minimill – works great – many thanks to all the people involved with the development of EMC!! Here what I did: Built a simple power supply – 10A @35V Transformer + Bridge rectifier + 2 x 22000 uF capacitors – no problems (see http://pminmo.com/simpleps.htm) Built my own stepper motor driver cards using the L297 / L298 running as a bipolar half stepped drive (check out st.com for the datasheet this gives a circuit linking the L297 and L298) – no problems Built an optoisolator card – had some problems here since EMC pulses are very short in the end I used 6N137 optos and the information here http://www.freescale.com/files/microcontrollers/doc/app_note/AN2342.pdf to build a 12 channel output only card i.e. step and direction for channels A, B, C, X, Y, Z. The card so built works really well – make sure you have truly isolated power supplies for the CNC and PC side. Purchased some low cost stepper motors (make sure you get the wiring diagram) and connected the X and Y directly to the table axes. For the Z axis I found a ball screw on eBay attached it to the mill by means of a purposed made plate with thrust bearings. The Z motor drives the ball screws by means of a 9mm timing belt. Try and drive your axes directly as this reduce backlash and since the steppers produce high torque at low revs so using belts and pulleys to increase torque is counter productive as the stepper must rev higher to get the required traverse speed – Initially I drove the X and Y axes using 2:1 reduction – this has now been junked and for direct drive via Oldham couplings. Sat down and fiddled with Linux(dark world of pain for me) and EMC (confusing initially but loads of help via this forum – it starts to make a lot more sense when you finally see a motor turn!!) and finally got the system going. It been running for around six months now and, touch wood, has operated faultlessly. The above development took me around 18 months in between the wife, babies, shopping, decorating ….. Hope this is of some use. Regards Andy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Colin Sent: 08 January 2007 13:49 To: emc-users@lists.sourceforge.net Subject: [Emc-users] Parport stepper setup Hello, I have been investigating using EMC2 and some stepper motors to a small milling machine. I have a cloudy area of understanding around driving the stepper motors. As usual I am trying to do it on the cheap Jand hence would like to develop my own stepper driver. I am hoping someone can provide some direction so that I don’t fall off any cliffs. So far I believe there is two ways to generate an amplified stepper signal (half, full etc). Method 1 Using the parport config to send a step signal and a direction signal for each axis. Run these signals into a stepper driver chip which is configured for the stepper phase that I require. This method should leave a few extra pins on my parallel port to play with later. Method 2 Use the functionality of the stepgen module to perform the required stepper phase for each axis. Amplify each signal into the motor. This method will use up more parallel port pins depending on the amount of coils in the stepper that I purchase, I may even need another port if 5 phases is required. Are both methods possible? Which method is the most common or gives the best result? I also intend to opto isolate the signals coming from the parallel port to protect my motherboard, is there any unforeseen problems doing this? Cole - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users - Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.phpp=sourceforgeCID=DEVDEV ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
