It doesn't sound like any standard Taig system, so you probably have a third-party controller on it. If you've got 4 channels, it shouldn't be difficult to add another motor. If not, if you don't mind doing some re-patching before doing 4-axis jobs, you can probably get it to work by switching the Y axis over to A, since you can do some kinds of rotary milling from a fixed Y position. Adding a channel to a defunct controller sounds like a thankless chore. You might consider scrapping the old controller system (you could put it in the Classified section of this site) and getting a new one that supports 4 axes - the new G540 from Geckodrives sounds like a good candidate.
It shouldn't be too hard to find a motor that will work for the 4th axis; you don't really need a lot of torque (what made you think you did?), but speed helps, since you've got some gearing to compensate for. Motors with lower holding torque often have lower inductance as well, which makes them more responsive. I'm assuming you are planning to use a rotary table,right? While I've seen "4-axis" machines on Ebay that simply hang a chuck on a stepper motor, that's not really recommended...]
Andrew Werby
www.computersculpture.com
Originally Posted by jncues  I'm a new member and I need some help. I purchased a Taig cnc mill about three years ago. It performes very well. I want to add the 4th axis and have encountered all sorts of unknowns. First, the controllers were made by Industrial Devices Corporation, model S5102, and are no longer in prodution. Second, the stepper motors are Vexta PH266-E1.2, which are no longer made. They are 8 wire motors going to 4 pins on the controller. The controller is labeled A+, A-, B+, B- and GND. The motors are labeled as 2 phase, 1.8 deg, 5 ohm, 1.2A. What little information I find about the controller is that it is current adjustable via resistor from 0 to 7 amps at 75 VDC. I need more torque than the nema 23 Vexta PH266's produce. What nema 23 motor is availabe that will run with these controllers with approx. 200 + in/oz of torque? |