3phase servo retrofit

[sbrpollock]

Al:

Does the Phase converter have to carry the whole load for this cabinet? The motor drives are the only components that are going to be three phase. Aren't the controlers and everything else single phase? If so wouldn't it pay to look into using the phase converter to supply only the motor drives?

#1 The Phase converter could be sized smaller if it isn't carrying the single phase load.

#2 Won't the phase converter loose efficiency if it is carrying an unbalanced (single phase) load? Wont it run better if it carries only the three phase?

[Al_The_Man]

Patrick, That is true it could be sized just strictly for the 3ph. Although Donny did mention that it was all three phase, However I would think the controller side should be no more than 1kva, If the controller side is single phase fed it could go on the two main feeds to unburden the artificial phase.
Al

[petek]

Originally Posted by whiteriver Does it matter that my motors are AC Servo Motors not DC???? Donny www.whiterivermfg.com

looking at the name plate on the motor you provided back on the first page it states that they are permenant magnet.dont be fooled by the term three phase these are not the same type motor as a standard three phase ac.If you try to plug them into a three phase outlet extremely nasty things happen!!!probabley giving the name plate info to rutex will verify if their drives are compatible.---i blew the picture up and saw the "ac"--- I don't know ask rutex.
Petek

[unterhaus]

My robot had a big dc power supply inside hooked directly to the three phase, but anything that used AC was single phase. Just a thought. Also, I would think the servo drives would work just fine on single phase. The first step in any such drive is to convert to dc. I can't see too well, but are the drives hooked up to single phase?

Those amps and motors would go for big bucks on ebay, I think. But I'd hate to see you downgrade from brushless servos. Of course, if you wanted to go to Mach2 control, you're going to need a step and direction interface. So far, the only step/direction interface to brushless is Rutex, and it's $100 per axis.

[whiteriver]

Unfortanatly all the motors are 3phase ac going into the drives. So getting them to DC as far as i can tell would be imposable without replacing the motors.
I decided against hooking up a phase conveter and running it as is with the teach pendant. It is not practical for what i need it to do. So now its a full retrofit to dc steppers or servos. I have a line on nema 42 2600oz/in steppers cheap. I could use gecko drives and Mach2.
The reason for the retrofit is 3 fold.
1 don't wanna spend the money on a phase conveter.
2 Hand programing or teach pendant for 5th axis continous carving Impractical
3 Converting output from CAD/CAM software to Karel language not possable.

A full retro fit is in order as in Arm and wrists will be pulled from the turrent and be placed on a 8' Z axis with a 9' X axis. That will give me a working envelope of 8'x4'x8' X,Y,Z. It will be used with one other axis for the turn table. Should make a hell of foam carver. I already have one screw Now need to locate the Z screw and the thk slides for the X and Z. The arm already has thk slides with a ball screw. Just need to pop in a nema 42 on it and be good to go.
From what i can tell Polar or Spherical corodanats are hard to program so going to a simple cartesian based design will be simple to come up with a post code. MAch2 should handle it just fine.
In the future if I need speed I can upgrade to servos. I'm hopeing for another $2000 i can get this going. And I guess I now have a 5 axis fanuc servo system for sale for $1000 or obo.
Also have 3 water cooled laser benders for sale that came out of the arm.

Donny

www.whiterivermfg.com

[unterhaus]

To be clear, the drives take the ac input, convert to dc, and then convert back to 3 phase to drive the motors. You almost surely can use single phase to power the drives. It might be a problem if they were twice as powerful.

EMC will drive a robot using G code.

[Al_The_Man]

Originally Posted by unterhaus You almost surely can use single phase to power the drives. It might be a problem if they were twice as powerful.

Not Generally with Fanuc, they have 3ph detection, if you lose one phase the drive shuts down and shows error, these are proprietary digital signal drives and are extremely hard to interface with other controls.
Al

[whiteriver]

I am not sure how to drive them with single phase. Each drive has 3 250vac inputs so that would make for 3 phase input. I don't wanna take a chance of burning up a perfectly good drive.

Donny

[Al_The_Man]

Its not only the power, for a while Fanuc has communicated with the drives by downloading the digital information to the drive and reading the status back from the drive processor. It is not as simple as a straight analogue drive etc.
Al

[unterhaus]

Originally Posted by whiteriver I don't wanna take a chance of burning up a perfectly good drive. Donny

Don't blame you for that.
I'm a big fan of your gallery by the way. Is that all your work? If it is, it's very impressive.

Don't forget that robots are potentially lethal.
Eric

[whiteriver]

Thanks Eric,
Yes all the work in my gallery is mine. I like to play to see what I can make with what i have. Check out my web site for more pics. Thats why i'm retroing the robot. Wanna do full 5 axis carving. Should be a blast once its done. Still looking for parts to get it all together. Hopefully 1 to 2 months top on build time. It all depends on what i find at what price. Need some 10' thk slides for the X and a 8' screw for the Z next..

Donny

www.whiterivermfg.com

[smoke]

Any chance the sst1500 from http://www.worldservo.com/ would drive some of the smaller 3ph motors. I have a couple of small Fanuc that I thought it may be possible to change the encoders on and use these drives or at least that was what I was hoping. Believe cntmotion.com folks use these drives. These folks, http://www.msys.net/cnc/ may handle the sst as well. Believe Dan Mauch, http://www.seanet.com/%7Edmauch/ sold some way back so would be familiar with them. Hope you folks will stay around as I want to scratch builld a table. Probably plasma, 5X10 and will need some help
Norm