Hi Andy Thanks for the great report. Glad to hear that you got it working.
Rayh On Mon, 2007-01-08 at 21:43 +0000, 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.php&p=sourceforge&CID=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.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
