Buying a VMC, what kind of phase converter do I need? How much air pressure do I need

[bellinoracing]

Well I found a VMC that I a planning on buying. It is a Cincinnati Arrow 750. Can anybody tell me what kind of phase converter I need to run it on 220v. single phase? I know very little about electricity but I have heard there are two types of converters and only one will work on a VMC. So can I count on this machine to double my power bill or are they halfway reasonable to run on single phase power?

Also how much air pressure do I need? I have a small craftsman air compressor that I am hoping I can get by with at least until I pay the VMC off and then I can invest in a bigger one. As far as I know they only need air to do a tool change so I wouldn't think they would need much but I honestly have no idea.

Thanks

[ARB]

You should get by with most any 5HP compressor. The cheap ones will drive you crazy with noise but they will work. We have run an Arrow with a little twin torpedo style roofing compressor in a pinch. You may decide to disable the air blow off in the tool changer to save some air. But that is up to you.

As for power. I personally would buy the DPC20 Phase Perfect. But I know that you can spend less on a decent rotary and make parts too. Your power bill will only go up in proportion to how much you run the machine. Your air compressor will hit it about as hard as the VMC will. You will find that most of the time the VMC is not using much power.


Good luck and we will need pictures when you get the machine.

[Ox]

I would reccommend a 30hp convertor.


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Think Snow Eh!
Ox

[cnctoolcat]

Phase Perfect converters seem to be the brand of choice for cnc applications...

[JP Machining]

I run 2 phase perfects DPC 20's for my machines. I think they upgraded models, and the DPC is perhaps no longer available. The new ones are better for the fact that 2 units can be tied together to a common 3 phase distribution panel. So in that aspect the newer ones are more like upgradeable. (new ones are white, DPC's are blue)

JP

[SeanC]

+1 for the DPC-20.

I run a Hurco VM1, a 10hp Leadwell 2 axis turning center, a small manual lathe and a manual mill of the one unit. Yes, VMC and lathe simultaneously ramping up/down with no problems at all.

-Sean

[Ox]

So how much is one of these PP units and how much ambiant hydro does it draw?


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Think Snow Eh!
Ox

[3t3d]

Do not forget the air drier. That machine will blow an air/oil mist through the spindle bearings continuosly. You don't want moisture in the spindle bearings.
Yes, the air does run continuously through the spindle, unless E-Stop is pushed.

If it is an 8,000 rpm machine, the only thing needed to run 10,000 rpm is the spindle chiller. And you can rig up something like that pretty simple.
Then change a parameter and you have 10,000 RPM.

Be sure and block up the head in the lowered position before it gets moved.
Wait until you are ready to move it through the doorway to remove the Z axis motor.

[bellinoracing]

Originally Posted by ARB

You should get by with most any 5HP compressor. The cheap ones will drive you crazy with noise but they will work. We have run an Arrow with a little twin torpedo style roofing compressor in a pinch. You may decide to disable the air blow off in the tool changer to save some air. But that is up to you.


Good luck and we will need pictures when you get the machine.

It will be a while until I get the machine. I still have to build my shop to put it in and I finally did get the building permit now that winter is here so it will probably have to wait until spring. I believe thats what I have is a noisy 5 hp compressor. I am planning to sell it and buy a bigger screw type compressor when money permits and build a shed outside the garage to house the compressor so I wont have to hear any noise.

So what is the air blow off? At work we have a bridgeport vmc that sends a blast of air through the tool holder to get any chips off the tool, a really nice feature I think. Do cinci machine have that ability? I didn't think they did but can't say for sure, if so how do you turn it on?

thanks and I will hopefully have some pics to post this spring

[bellinoracing]

So how much should I plan on spending to get one of these DPC20 Phase Perfect converters?

Also I am hoping to eventually end up with a shop with a VMC (maybe even 2) a manual lathe, manual mill, and maybe a long ways down the road a cnc lathe. Can I run multiple machines with one converter? Would it be cheaper in the long run if I bought a bigger converter(I am guessing they make different sizes) than I needed right now so later I could wire other machines to it also?

[JP Machining]

IIRC the DPC 20 was around 4500. If you are planning on multiple machines you can wire the PP into a 3 phase panel and go from there.

If I were in your shoes, I would get the 20 hp PP (the new white ones) and a 3 phase panel big enough for twice the output amps of the PP. That way down the road if need be you can buy another of the 20hp PP and simply wire both into the same panel (the new white ones can be tied together, old blue ones can not).

JP

[bellinoracing]

Originally Posted by JP Machining

IIRC the DPC 20 was around 4500. If you are planning on multiple machines you can wire the PP into a 3 phase panel and go from there.

If I were in your shoes, I would get the 20 hp PP (the new white ones) and a 3 phase panel big enough for twice the output amps of the PP. That way down the road if need be you can buy another of the 20hp PP and simply wire both into the same panel (the new white ones can be tied together, old blue ones can not).

JP

$4500 are you serious? I was hoping to get this machine wired up for less than $800. I have a buddy that is an electrician and he said he can get me a "good" converter for $400. I believe he said it was a rotary converter. He said he did wire up a mill with one before but he dont remember if it was a manual or a cnc mill. Does anybody know if a rotary converter will work on a VMC? Is there any possible way to get a VMC wired for $800?

[bellinoracing]

Originally Posted by 3t3d

Do not forget the air drier. That machine will blow an air/oil mist through the spindle bearings continuosly. You don't want moisture in the spindle bearings.
Yes, the air does run continuously through the spindle, unless E-Stop is pushed.

If it is an 8,000 rpm machine, the only thing needed to run 10,000 rpm is the spindle chiller. And you can rig up something like that pretty simple.
Then change a parameter and you have 10,000 RPM.

Be sure and block up the head in the lowered position before it gets moved.
Wait until you are ready to move it through the doorway to remove the Z axis motor.

That is good to know but I think 8,000 rpm is fast enough at least for right now.

So how much can I plan on paying for a drier?

I am going to have to have the seller ship this machine to me so hopefully he does everything needed to transport the machine safely. But just curious how do you block the head up? Do you bring the spindle down onto a block of wood until it alarms out and then shut it down or can you put the z axis drive into a neutral somehow?

thanks again

[706jim]

New machines are usually shipped with the head resting on a block of wood, close to the maximum "down" z position. Those equipped with a spindle head counterweight have the weight resting on a bar that fits through the machine frame.
Shipping brackets also immobilize the x and y axis to present ballscrew damage.

[ARB]

On the Arrows there is a air blast inside the tool carousel that helps to keep the tapers clean. It don't amount to much but it uses quite a bit of air. Not a ton but if your short on air it may be worth disabling it.


Ox my DPC20 draws about 6 amps when idling. Which amounts to about one bank of lights in our shop. It also turns on without any large current inrush. IE no lights dimming. I know it is a spendy option but it just works and I mine.

I have mine set-up to power the whole shop. It has handled anything we have thrown at it so far. That's a couple VMC, a turning center, air compressor and the manual machines. It is not uncommon to have 5 machines running and the air compressor.

Mind you that I have carefully shopped my machinery to have low current requirements.


YMMV

[JP Machining]

From what I remember on rotary phase converters, if you want one to run a cnc then you need twice as big a rotary so that the power where you need it is better balanced.

JP

[Ox]

For $400 your looking at a USED rotary converter.

Not that there is enything wrong with that ... but there aint much at all of a used market for the Phase Perfects. (new contraption) So you are comparing a used cheaper solution to a new expensive solution.

If your pinchin' pennies - I would recomend a used rotary. I run many CNC's on mine for many yrs.


Gee ARB! 5 machines? This is your part time - after skewl gig aint it?


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Think Snow Eh!
Ox

[bellinoracing]

Originally Posted by ARB

On the Arrows there is a air blast inside the tool carousel that helps to keep the tapers clean. It don't amount to much but it uses quite a bit of air. Not a ton but if your short on air it may be worth disabling it.

YMMV

That would be nice. My biggest complaint with the arrow machines is that they seem to get chips on the tool holders easily and any speck of anything and they start making bad parts. Most of the time when we use a shear hog tool we put a program stop right after it unloads that tool, and note to clean the tool holders by hand which is a big PITA.

[bellinoracing]

So it seems like the ideal thing to do short of getting 3 phase power put into my shop would be to get a phase perfect digital converter. So what is so bad about a rotary converter? Are they just not as efficient or reliable as a digital converter? How big of a rotary converter do I need? I believe this machine has a 10hp spindle motor so does that mean I need a 20hp rotary converter? I have no idea what it has as far as axis drive motors.

[Ox]

A 20 would quite possibly work. I would opt up to the 30 if you had a choice.

On the other hand, you can git away with less if you set your ramp time parameters longer it will actually draw less amps. (Take an extra second or two to git to 8K)

Another option is to step up your RPM if needed.


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Think Snow Eh!
Ox