Minertia servo motor and it's control - Page 1
Forum section: electronics / projects

author: V_King
author_rank: Regular Contributor
timestamp: January 24, 2014, 09:14:32 pm
content: Hello,friends company was shutting one of their sites, and I had my hands on a few IBM 4224 matrix printers before they went to the skip.Apart from stepers, I've got Yaskawa Electric Minertia J Series Servo motors. Looks like this (not my picture):Does anybody have any experience with them?I can not exactly identify which model it is. I've got Yaskawa brochure from theirwebsiteBut neither the the markings nor the measurements match any of the motors listed in the brochure. They must have been made for IBMs specs?Also, can anybody point to some good reads of how to make a servo controller. I prefer using AVR's, but could not find anything in their website and google is full of those chinese plastic servos tutorials, without anything more serious.Thanks

author: bubba198
author_rank: Contributor
timestamp: June 20, 2015, 08:40:30 pm
content: I also thought that making a servo drive should be straight forward using an arduino but quickly deduced that the OEM servo drives must have some pretty fast processors inside.. long story short I bought Yaskawa servo drive from eBay for my application for less than a 100 bucks.What caught my eye as a road block was primarily the task of reading the encoder. My servo motor was mid-range size using standard incremental three channel quadrature encoder. At 2048 pulses per revolution there was no way I can read that waveform at my motor's max RPM of 1,500 -- that's 3.072 MHz of a waveform. Ouch.So I got a Sigma servo drive and the motor has been working happily ever after. I program it using the free SigmaWin+ software and all I really had to do is make the serial cable since Yaskawa wasn't using the standard serial io pins on the db9 connector.

author: ovnr
author_rank: Frequent Contributor
timestamp: June 20, 2015, 09:55:44 pm
content: Quote from: bubba198 on June 20, 2015, 08:40:30 pmNot entirely on topic, but you forgot that RPM != RPS. Actual frequency is 50 kHz, not 3 MHz. Also, consider a micro with a built-in quadrature decoder - I know a few PICs have that.

author: LaserSteve
author_rank: Super Contributor
timestamp: June 21, 2015, 03:53:35 am
content: If you get stuck, there are many dedicated chips for reading and tracking encoders, some available in hobbyist quantities. Most have interpolation for even finer resolution.Steve

author: JohnSL
author_rank: Regular Contributor
timestamp: June 21, 2015, 02:13:10 pm
content: You could use a Cypress PSOC 5 instead of an Arduino. They have a programmable digital section where you can drop in a quadrature decoder that will have no problems keeping up.

author: H.O
author_rank: Frequent Contributor
timestamp: June 21, 2015, 05:31:16 pm
content: If you're more into PIC and don't feel you need the power of a 32bit Micro then the 18F2431 or 18F4431 might be interesting. It's got the quadrature counter, a pretty powerfull PWM module, a special (for being an 8bit PIC) type of ADC and all the other usual stuff. It's pricey for an 8bit PIC but it's a cool little chip. I'm using it for PMDC servo motor control.

author: bubba198
author_rank: Contributor
timestamp: February 04, 2017, 06:52:01 pm
content: Quote from: ovnr on June 20, 2015, 09:55:44 pmYou're correct; my bad! Yes it is around 50kHz LOL (RMP/60)*2048=waveform