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Centroid atrump cnc mill conversion to single phase

Kennyj64

Plastic
Joined
Jun 14, 2017
I have acquired 2 atrump m218 mills with centroid m400 controls and I am looking to see what I can do to run them on single phase power as low cost as possible. They are setup for 220v 3-phase now. Anyone have suggestions? I have read that maybe setup controls on single phase and spindle on rpc but not seen any details about it.
 
I wouldn't do it. Period! You will not be happy with the results. However, you should consider converting your shop to 3 phase with the use of a single phase to 3 phase inverter.
 
Look under Atrump or Centroid videos. There is a training video that shows how to hook up the machine to either single phase or 3 phase power. I have a Atrump B3EC manufactured in 2008 that meets these requirements, and I operate it with 220 volt single phase power.

Search Centroid Cnc Videos. There is a training video there that is 1 hour and 28 minutes in length, and the wiring for 220 volt 3 phase and 220 volt single phase is covered.
 
I wouldn't do it. Period! You will not be happy with the results. However, you should consider converting your shop to 3 phase with the use of a single phase to 3 phase inverter.

What is the basis of this opinion? Something about a Centroid that does not like single phase?

I've been running my Mori Seiki on single phase for nearly 4 years now with no problems.
 
What is the basis of this opinion? Something about a Centroid that does not like single phase?

I've been running my Mori Seiki on single phase for nearly 4 years now with no problems.

This single phase/3 phase issue has been with us for a very long time. All electric motors work by magnetic impulse regardless of their type. The big advantage 3 phase motors have over single phase is a more frequent impulse count per revolution. In other words, they are smoother and smaller for a given power. The dilemma in the US is that 3 phase power only exists in industrial zones and it is very expensive to bring elsewhere. In the past we had pseudo 3 phase generators using single phase input and idler motors as the only affordable solution, but things have changed today. Inverter technology has improved by leaps and bounds. Inverters now can produce very smooth digitally created sinusoidal output both efficiently and inexpensively with very high reliability. We see this most in VFDs, but inverter use has popped up everywhere, including UPS systems. These make a lot of sense, as they can be powered by a multitude of different sources. Where whatever energy source is available, it is converted to DC. This DC can be stored in batteries and/or directly used to produce eclectically quiet, sinusoidal, voltage correct, smooth AC single or 3 phase at any frequency one desires. Most importantly it can done at less cost than either wiring in a 3 phase service or a mechanical pseudo 3 phase system and every day the cost of these inverters drop. I think today, it is the only way to go.
 
I run one of these every day at my day job. It has pluses and minuses if you need any help with anything quirky about it, maybe I could be helpful to you. We run ours on 3 phase and I don't know anything about wiring for single phase, so I am afraid I can't be helpful there.
-Greg
 
This single phase/3 phase issue has been with us for a very long time. All electric motors work by magnetic impulse regardless of their type. The big advantage 3 phase motors have over single phase is a more frequent impulse count per revolution. In other words, they are smoother and smaller for a given power. The dilemma in the US is that 3 phase power only exists in industrial zones and it is very expensive to bring elsewhere. In the past we had pseudo 3 phase generators using single phase input and idler motors as the only affordable solution, but things have changed today. Inverter technology has improved by leaps and bounds. Inverters now can produce very smooth digitally created sinusoidal output both efficiently and inexpensively with very high reliability. We see this most in VFDs, but inverter use has popped up everywhere, including UPS systems. These make a lot of sense, as they can be powered by a multitude of different sources. Where whatever energy source is available, it is converted to DC. This DC can be stored in batteries and/or directly used to produce eclectically quiet, sinusoidal, voltage correct, smooth AC single or 3 phase at any frequency one desires. Most importantly it can done at less cost than either wiring in a 3 phase service or a mechanical pseudo 3 phase system and every day the cost of these inverters drop. I think today, it is the only way to go.

No relevance really for users of small CNCs. The OPs mill runs the control on single phase 110 or 220 to start with. The servo drives take the incoming power regardless of single or 3 phase and convert it to DC before output to the motors as DC or digitally created AC and many brands are fine with single phase input. The spindle drive could be inverter driven which in many cases will be happy to run on single phase input too. If the spindle is a mechanical variable speed drive with a 3 phase motor, only then will 3 phase need to be used or an inverter installed to run it.

Lots of people have thrown away good money adding roto-phase or phase perfect units to run small CNCs that with a bit of thinking, are just fine with single phase power.

Small machines without hydraulic systems are almost always great candidates for single phase operation.
 
No relevance really for users of small CNCs. The OPs mill runs the control on single phase 110 or 220 to start with. The servo drives take the incoming power regardless of single or 3 phase and convert it to DC before output to the motors as DC or digitally created AC and many brands are fine with single phase input. The spindle drive could be inverter driven which in many cases will be happy to run on single phase input too. If the spindle is a mechanical variable speed drive with a 3 phase motor, only then will 3 phase need to be used or an inverter installed to run it.

Lots of people have thrown away good money adding roto-phase or phase perfect units to run small CNCs that with a bit of thinking, are just fine with single phase power.

Small machines without hydraulic systems are almost always great candidates for single phase operation.

Centroid probably put a VFD in the cabinet so the M400 can control the spindle speed.
 
As Vancbiker said, the controls are run off single phase and the motor is the only 3 phase device. I have a similar setup, although run on 3 phase now, it was connected to single phase previously. I just ran a VFD for the motor and used auxiliary contacts off the motor starters to control forward and reverse. I didn't use the speed control but if your control doesn't specifically have a VFD control, you could swap the speed pot for a different pot and wire straight to the VFD voltage reference input.

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I just bought an Atrump BF6C today. The dealer said I couldnt separate the power and wanted to argue about it so I let it go. He insisted that the entire system required 3 phase and offered to toss in a rotary phase converter to shut me up. I will probably still look into the control box and see what I can do because a 4K spindle is a little bit on the slow side and a motor upgrade or vfd if it’s inverter rated would be ideal. Either that or mount a sub spindle to the side of the head. I imagine the AC servos themselves are 3 phase and not sure other than a phase converter for addressing those so maybe that’s what he meant? The drives are probably 3 phase only. Seems to me I’d have to go to new servos and may as well upgrade entire control at that point. No time at the moment I need a running mill I can depend on.
 
Well low and behold do not use an rpc on an Atrump at all. The dealer is now repairing and replacing the main control board because even through we have the cnc AD15 rpc it still fried out the board. We noticed that the servos were a slightly losing position over the past few days and then poof the board burnt up. The only explanation is the rpc regardless how fancy it was a bad idea. The irony I told them beforehand it should be converted to single phase but they insisted I was wrong. Heck we could’ve just connected the motor/Vfd to the rpc and the rest to single phase and it would’ve been ok.
 
Just adding my 2 bits. I have a B6FC run on single phase. No issues.
The Centroid AllinOne control does the hefty lifting and there is also a VFD involved.

If I moved to a 3 phase location it is a simple matter of moving some power wires around.
Search out that Centroid video mentioned.
 








 
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