On Saturday 31 October 2015 23:40:41 Jon Elson wrote: > On 10/31/2015 10:15 PM, Gene Heskett wrote: > > I have 3, 8 wire motors, I presume intended for direct 24 volt > > operation since the coil ohms is 145, and the current/phase matched > > that at 166 mills per coil. > > Ugh, these motors will have HORRIBLE performance. Maybe > they could work for a tool carousel, but even there I think > you might be disappointed. Just take a guess at the coil > inductance, and you can see that it would take a long time > for the current to ramp up. > > My guess is these are 120 V synchronous motors, to be run > off a 60 Hz 120 V AC line with a phase shift capacitor. > They were developed by Superior Electric in the 1960's to > run powerstats (Variacs) remotely from a lighting control > board. They were called Slo-Syn motors. People found they > made passable stepper motors for positioning use, and pretty > soon a whole new industry popped up. > > Jon
I am familiar with slow syn's, we used them in the pan & tilt mechanisms that were on the Trieste when it went down into the mohole with Lt Walsh and Jacques Cousteau in it, in Feb 1960. They worked well. These are not slowsyn's, they are an early double stack stepper, 15 degrees a step, but with a substantial 15/1 gearbox attached, so they move 1 degree per full step. The 500 hz charge pump would likely need a /8, giving a 62.5 hz effective drive rate. Thats still 62.5 degrees a second at the output shaft and actually a fairly speedy rotation if its driving the wheel I posted a pix of which is 72 degrees per pocket. That would get from tool pocket to tool pocket in 1.25 seconds or all the way around in nominally 6 seconds. A further /4 to a 2nd copy should move the whole thing in and out of position as thats going to be a couple lbs to move a foot or so & might need a PID module to profile the accels/decels. A 3rd one would have plenty of power to run the heads gearshift shaft ( took the detent ball assembly out, turns easily & smoothly now, but would also be hanging out if a direct drive. That leaves a solenoid to engage the drawbar holding wrench as the final problem. I see that as a socket with a disk, with a sturdy flag sticking out, to turn with the spindle full time, but with a solenoid driven pin to block the rotation when its desired to hold the drawbar to unlock the tool, or lock in the new tool. With a substantial flag on the disk/wrench the solenoid could stick up a pin to block & lock the socket, and yet give most of a turn so that when it hits the pin, the drawbar will be loosened or tightened depending on the direction its turning when it hits the pin. Pocket to pocket moves would simply be issuing the correct number of steps to get to the next pocket, in this case 72. If thats not the desired pocket, do it again until it is. The devil of course is in the details. Film at 11 of course if & when its working. I haven't even checked to see if I'd have to offset the tool pocket rotation motor in order to get clearance to the head when its in the active position. I fully expect I'll have to unless I put that motor on the bottom. That would also solve the potential interference between the gearshift motor and the tool pocket motor too. Since its not designed yet, its just a design detail. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
