Greetings all; Got the new driver for the x motor a few days ago, a M542T, which looks a lot like the 2M542's I bought a 7 pack of most of a decade ago, and this was the only failure, which occurred while powered up at 42 volts, but no input or motor load. Has anyone had less than expected performance from one of these?
Still no psu for the x motor. Got a shipping notice 3 says ago that said the psu that was supposed to be in noo joisy when I bought it on ebay, was shipping from seanzow, estimate delivery after Christmas. Z is moving, but not optimized yet, thinking of reducing the divisor as an inch is in the 238xx range for scale. I did manage to get the 254 volt 4 pole Hubble twist-lock socket on the wall warmed up yesterday. I could pull thru the 3 sweep length of 1/2" EMT conduit easy enough, but gave up and stripped the sheathing off the romex to get it the last 2 feet into the service box one wire at a time, thru the last 2 "pull elbows". I'll never buy another of those headaches despite LB's being 5x more expensive. Changed the breaker from a dual 20 to a dual 15 I had as this 15 is more than the lathe will need anyway. Question: This phoney VFD cannot be made self protective in terms of motor minimum safe speed, without it haveing a very brutal start up jerk when reverseing, getting jump off the table worse if the minimum hz setting is raised to a real world safe setting in the 30+ hz area. It will run at 15 hz, but at no load is drawing an amp more than the nameplate FLA doing it so I've never had it running that slow for long as it does heat it considering the fan isn't moving enough air for adequate cooling at 4xx rpms. Even at that speed, its still very stiffly running, I cannot noticeably slow it with a stick of oak against the pulley, smoking. So I think I will skip that setting by putting it down to essentially zero in the VFD configuration, and do the start/stop profiles with the same hal code I put in TLM to reduce the broken drive parts in it, which must be working as I haven't broken a drive part it it in the nearly a year since I did it. And a couple of times I've made it work its butt off for many hours at a time, piles of cast iron sand on the table that the apron was sweeping away as it moved. This accel limit into the PID I put in the hal file has worked well, for the PM DC motors on both TLM and the G0704. So I am considering shutting the related limits in the VFD off or as close as I it let me, and substituting my own in the hal file by importing that code block into the .hal file in the R-Pi and tuning it appropriately. Short description of this code: A limit3 controls the maximum rate of change fed to the PID (which doesn't exist in the R-Pi's hal) so its output will go directly to the SpinX1 via the 7i90's pwmgen. This block of code does a hold on the direction command from motion such that the direction signal going out is held from changing until the pulse rate from the encoder says its down to a millisecond or so between pulses. The limit3's input is mux2'd to zero volts at the same time as this hold is in effect causing the speed output from the limit3 to decrease to zero when the motion direction is not the same as what is being fed to the motor controller. When the encoders output says its nearly stopped, then the direction output is allowed to change, and at the same time, the mux2 reconnects the input of the limit3 to motions speed request. This results in a very smoothly done motor reversal, doing regenerative braking when slowing to zero to make the reversal, and then doing the same to the accel curve as it accelerates in the other direction. Since its not in a below practical speed for the VFD/motor for more than a small fraction of a second, it seems like I ought to be able to do it to the VFD as its regenerative braking is as observed so far, to be stronger than the DC braking it seems able to do. The first thing I make will be a locking clamp on the back of the chucks back plate so it can't unscrew itself. :( IMO, the flange on the spindle isn't thick enough to drill and pin for a lock, and the clamp collar pin to pin hole in the flange becomes critical. In the meantime, its reducing the chance it would unscrew the chuck since it is not now locked except slamming it against the end of the spindles threads. What say the old hands here about this scheme for controlling the VFD and a 1 hp 3 phase motor its driving? Thanks everybody. 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
