That is what I was thinking, the existing motors are quite old and are probably not as strong as they should be either, so if I am buying new drives and motors anyway, I thought switching to servos would be a good idea, especially since I would need to get some sort of hardware step generation to make use of a microstepping drive.
Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -- P. Graham Dunn Phone: 330-828-2105 E-mail: to...@pgrahamdunn.com 630 Henry St. Dalton, OH 44618 www.pgrahamdunn.com -----Original Message----- From: Jon Elson [mailto:el...@pico-systems.com] Sent: Thursday, June 14, 2012 10:33 PM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Brushless Servo Selection? cogoman wrote: > 450 Oz-in. steppers are pretty hefty devices. > I followed the link to the Keling website, and the heftiest motor > they listed was a maximum of 6.3N.m, which I assume (correct me if I'm > wrong) means Newton-Meters. The conversion calculator I used gave me 56 > inch pounds, a little more than a tenth of the torque your steppers > should be able to put out. If you get outright stalls with 450 inch > pounds, you will more often get outright stalls with 56 inch pounds. If > you are missing steps, it's probably not the motors' faults. Something > else is probably at work here. > > Thats inch-POUNDS! 16 times inch-Ounces. 56 In-Lb is 896 Oz-In, so you have made a mistake. Also, steppers, ESPECIALLY with non-microstepping drives, are susceptible to timing variations and resonance issues. If you used a hardware step pulse generator and microstepping drives such as the Gecko 201 or 203 drive, you probably would get rid of the errors. At 1000 RPM, all reasonable steppers have lost significant torque from their holding torque rating. But, for peace of mind, and since you would need to replace the drives anyway to go with microstepping ones, you might as well go the servo route. It isn't that much more expensive. Jon ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
