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retrofitting anton cnc lathe servo question
hello all,
i recently purchased an anton cnc lathe, a small but nicely build cnc lathe from the late eighties. i want to change the control to mach3.
i got one question regarding the main spindle motor. i am not very familiar with servos, maybe someone can help. from the spindle motor 3 cables come out, all white. is this a servo or could it be a regular 3 phase motor that could also be run with a vfd?
there is also a transducer and a rotary encoder rod 420 c 1000. here are some photos.
thanks for your help,
michael
Re: retrofitting anton cnc lathe servo question
That appears to be a BLDC (brushless DC) servo motor. That would indicate it is a 3 phase motor with a permanent magnet rotor. It MIGHT run on a sensorless vector VFD. But the real question is what is the rated voltage?
If the existing drive is working, it looks like it can be controlled by an analog signal from the CNC controller. Mach3 will output the analog signal when using the correct hardware that will output the analog signal.
Re: retrofitting anton cnc lathe servo question
jim,
thanks. if it would be a dc servo motor, then could i use an uhu to drive it? i have some uhus laying arround. i would rather change the whole electronics to something new and not use the 30 year old stuff.
michael
Re: retrofitting anton cnc lathe servo question
I don't know what a ''uhu'' is.
Re: retrofitting anton cnc lathe servo question
uhu is a servo controller, here in cnc zone is an entire section on it: http://www.cnczone.com/forums/uhu-servo-controllers/
you can drive dc servos with step/dir signal with it.
Re: retrofitting anton cnc lathe servo question
OK, I see. No, those controllers will not run that motor. The uhu controllers are for brushed DC motors. You have a Brushless DC motor, which is a 3 phase motor.
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Re: retrofitting anton cnc lathe servo question
so then it would be best to lengthen the spindle and put a pulley and a spindle index pulse on it. i have a 1,1kw 3 phase motor with 2800 u/min laying around and use that with a regular vfd?
the end of the spindle is 12.5mm thick and i could put another bearing in the end plate (see photos) for support. mounted ist a 125mm chuck. the idea is not to rough 5mm in steel on this lathe. would that be a good and easy solution?
Re: retrofitting anton cnc lathe servo question
If the present motor and drive is working, I would look at attempting to use this over a regular motor and VFD, the one you have is far superior.
It could well have ±10vdc control.
Al.
Re: retrofitting anton cnc lathe servo question
My first choice would be to see if the original spindle drive works. Nothing wrong with 30 year old electronics if they are working, I'm running almost 30 year old servo drives in 3 machines. If the drive doesn't work, then installing the other motor might be an option.
Re: retrofitting anton cnc lathe servo question
the owner said it would be working but it was sitting in his garage for a long time. so i would not bet my life on whether the motor is working or not. and i can not test it because the old control is already taken out. if i understand correctly to get mach3 put out a +-10vdc signal, you have to use the csmio which is more then 500€. as i am on a budget i would rather buy a vfd for 150€ and some pulleys. it is said that with a spindle index signal you can also control the speed of the spindel with mach3 and also do threading. why would the old spindle drive be superior? i aim to use this lathe for hobby/semiprofessional use, it will not run all day.
thanks for your help,
michael
Re: retrofitting anton cnc lathe servo question
Most likely the original had not only rpm syncing but possibly positioning down to zero, also the motor is superior to AC Induction motor.
±10vdc control. on mach only requires a simple D/A convertor as this is how Mach usually controls a VFD/spindle.
The method of threading with Mach is AFAIK still with a once/rev signal off the spindle to indicate the rpm, unlike some higher controllers, Kmotion, Galil etc that use gearing.
Al.
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Re: retrofitting anton cnc lathe servo question
It looks like you could simulate an analog signal by hooking a 1.5 volt battery between pins 11 and 12 on the drive, or maybe pins 12 and 13. That would tell you if the drive as working. Looks like pin 5 might be the enable switch.
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Re: retrofitting anton cnc lathe servo question
jim and al,
if i understood you right that would be great news. the bob can put out 0-10v depending on the rotation speed. would i use that signal from the bob or as an alternative this d/a converter: https://www.ebay.com/itm/PWM-0-10V-D...QAAOSwFdtX1iH6
additionally i would have to install the pulse index sensor on the spindle to let mach3 control the speed?
i made again some more photos of the servo drive, especially the pins. so you suggest to fire up the control and put 1,5v between pin 11 and 12, the delta ref pins or between pin 12 and 13, the delta ref and com?
Re: retrofitting anton cnc lathe servo question
Depending on the BoB you get, some of the better ones have a 0-10V analog output. Basically the same circuit as the D/A converter that you linked to.
For testing, you will have to supply proper power to the drive. I have no idea what voltage it is designed to run at. The input to the drive is supposed to be 3 phase, but if you don't have 3 phase power available it should work on single phase at reduced output, but you must have the input voltage correct. I was not able to find any documentation for that drive, but there are a few repair shops that have that drive listed. So maybe you could email some of them to see if they would help.
It looks like pins 11-12, or 12-13 are the analog input. I would try 12-13 first.
It also looks like you need a switch between pins 3-4-5 and COMM to enable the drive.
There is also a pretty good chance that the motor would run on a VFD, you just have to get the voltage and output power correct. Electrically there is not a lot of difference between a modern VFD and a servo drive, the servo drive is just more precise in its control. A sensorless vector VFD might work just fine with that motor, but I have never tried to run a BLDC motor with a VFD.
To run with Mach3, you would have to install a sensor on the motor shaft.
Re: retrofitting anton cnc lathe servo question
thanks jim, that is good news. i have 3 phase power available, i can use the old setup for test. did i understand you correctly that i bridge pin 3,4 and 5, put them to a switch (or relay in a later mach3 setup) and connect the other pin to the COMM?
do i need the transducer and a rotary encoder rod 420 c 1000 to be attached to the servo controller?
Re: retrofitting anton cnc lathe servo question
I think bridging pins 3-4-5 to COMM is correct. It looks like that enables the drive.
I'm pretty sure the transducer needs to be connected. I think it is a resolver and is used by the drive to properly commutate the motor. The problem here is that you have already remove the transducer and it needs to be timed to the motor for proper operation. I hope there are some alignment marks that will allow proper timing.
I don't think the encoder needs to be connected.
Re: retrofitting anton cnc lathe servo question
hi jim,
today i tried to connect just as you told me.
i first removed the two existing leads at pin 11 and 12, then connected a power supply to pin 11 and 12 (3-5v). i bridged pin 3,4 and 5 to com.if i switch on the main power for the servo amp, the green led for power lits. if i then connect the pins 3,4 and5 to comm, three more led turn on: torque enable, stand by and speed enable. unfortunately the motor does not turn. i mounted the transducer from photographs i've taken before, so it should be somewhat in the position as before.
the other cables from the other pins i left in the connector. that where pin1,2,3,14,15,18. was that alright or should all of them be disconnected?
do you have any ideas?
thanks,
michael
Re: retrofitting anton cnc lathe servo question
That's a good sign that the LEDs light up. Understand that I am making my best guess as to what terminals should be connected. Try disconnecting the wire that turns on the torque LED, and leave the speed one connected. Terminal 5 seems to be the one that turns on the output, but maybe it needs to be disconnected to run rather than the other way around.
Not sure about the other terminals, they are not shown on the diagram pictures.
If you can find the documentation for that drive it would be very helpful. The manufacturer seems to still be in business, so that might be a resource.
Re: retrofitting anton cnc lathe servo question
thanks jim, it seems you were right that terminal 5 should be not connected. i bridged pin 3 and 4 to comm and the green led with torque control did not lid this time. however the motor also does not turn. the stand by led is still on. is that all right? if comm is not connected, just the power led is lit.
i contacted el.ge milano but dont have great hope that i will receive an answer.
Re: retrofitting anton cnc lathe servo question
i tried a little more. if i disconnect the original cable from pin 3 and leave pin 4 not connected (pin4 stsw= standby switch) and connect pin 3 to comm, then only the speed enable and power led lit. still no motor.