# Question on a VFD and my Mill



## CRCJeff (Feb 9, 2010)

I have a PM 10x50 Mill with v-pulleys. Here's the link: 

http://www.machinetoolonline.com/PM1050Mill.html 

I use a 5HP Rotary Phase converter, my question is, If a buy the correct VFD for my AC motor does that make my mill variable speed?

Thank You


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## 65535 (Feb 9, 2010)

You'll need a 3HP 220V 1PH VFD. Or a 3HP 220V 3PH VFD.

THe latter uses the RPC to generate the 3PH and is necessary to keep the RPC.

The Single Phase VFD eliminates the RPC and converts your 220V 1PH to 220V 3PH.

So depending on pricing you may be able to sell the VFD and buy a single phase input VFD or just stick to a 3PH.


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## precisionworks (Feb 9, 2010)

The easiest way to go is run the mill directly from your 240v 1ph supply, using the VFD for both phase conversion & variable speed. Keep the RPC as you'll probably want to use it for a larger lathe or something similar.

Will Quiles has a detailed thread on VFD conversion for his mill - and yours will be much easier as the 3ph motor is already on the machine.


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## CRCJeff (Feb 9, 2010)

So the VFD will eliminate the need RPC completely?

Thanks guys


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## wquiles (Feb 9, 2010)

CRCJeff said:


> So the VFD will eliminate the need RPC completely?
> 
> Thanks guys



Yup, it not only eliminates the RPC completely, but it also gives you the soft-start and variable speed as well. Here in this link, starting on post #135, I showed my VFD conversion for my knee mill, just a smaller version of yours.

Will


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## CRCJeff (Feb 9, 2010)

Thanks again guys. It seems I'm constantly changing the belt configuration for speed, this will save me some time and hassle.

Any suggestions on which brand? I've been looking on ebay(I'm a junkie)and their are many to choose from.


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## wquiles (Feb 9, 2010)

CRCJeff said:


> Thanks again guys. It seems I'm constantly changing the belt configuration for speed, this will save me some time and hassle.
> 
> Any suggestions on which brand? I've been looking on ebay(I'm a junkie)and their are many to choose from.



Suggestion: Stop looking at Ebay - you have no idea if the stuff will work at all, what documentation comes with, that support (if any) you will get from the manufacturer, etc.. (darn it - I am starting to sound like Barry :devil. Buy a new/quality VFD, like the AC Tech that Barry and I used. I purchased mine (2 so far, and another one shortly) from WolfAutomation:

NEMA4: link ...

NEMA1: link ...

Will


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## StrikerDown (Feb 9, 2010)

I wish you guys would stop talking about VFD's! My RF-31 already suffers from poor finish quality from a motor that vibrates and the need to swap belts around to change speed!

So next thing you will be saying is that a Baldor motor would be smoother and more balanced than my cheep Chinese motor as well as a 3 phase motor being even smoother yet! 

... Not to mention the variable speed thing!

Edit:

Jeff I love your mill!


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## CRCJeff (Feb 9, 2010)

wquiles said:


> Suggestion: Stop looking at Ebay - you have no idea if the stuff will work at all, what documentation comes with, that support (if any) you will get from the manufacturer, etc.. (darn it - I am starting to sound like Barry :devil. Buy a new/quality VFD, like the AC Tech that Barry and I used. I purchased mine (2 so far, and another one shortly) from WolfAutomation:
> 
> NEMA4: link ...
> 
> ...



Thanks Will


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## precisionworks (Feb 9, 2010)

> next thing you will be saying is that a Baldor motor would be smoother and more balanced than my cheep Chinese motor as well as a 3 phase motor being even smoother yet!


You are reading my mind, Ray 

The only drawback to VFD controls is that there is always the need for "just one more". My disc/belt sander was first, the Burr King second, the wire brush machine third, and the drill press fourth. Funny, but the drill press is the machine that's gone from almost useless to totally awesome (the Bison keyless chuck also helped).

Just one more, for the mill, and I'm done. Maybe.


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## wquiles (Feb 9, 2010)

precisionworks said:


> Just one more, for the mill, and I'm done. Maybe.


Right. Maybe. That was exactly my though as well after doing the VFD on the knee mill - I now just have the lathe to do. That was "before" the deal on the Quincy ...


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## precisionworks (Feb 9, 2010)

> Suggestion: Stop looking at Ebay


+1

I search eBay constantly for drives, and there are always a bunch that won't work for me - either they are 480v (really common), or they require a shaft encoder (which comes attached to a $3000 motor), or they are incomplete (no digital operator, no documentation, etc.).

A few nice drives are listed from time to time - some of the better Allen-Bradley models, Square D (Telemechanique) Altivars, T B Woods E-Trac, Siemens, etc. Most sell for about what a new ACTech SMVector goes for, but the ACTech comes with a full warranty plus tech support.

Drives are like most everything else electronic - they are a commodity item. Hard to beat a new one.


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## CRCJeff (Feb 10, 2010)

OK, So the best one to go with is the NEMA-4X, correct? This one will eliminate the RPC?

Next, I have a 120v drill press I need to vary the speed on, will I need the same unit or do they make something different for that application? 

Bear with me guys, this electronic stuff is a little complicated for me


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## 65535 (Feb 10, 2010)

CRCJeff said:


> OK, So the best one to go with is the NEMA-4X, correct? This one will eliminate the RPC?
> 
> Next, I have a 120v drill press I need to vary the speed on, will I need the same unit or do they make something different for that application?
> 
> Bear with me guys, this electronic stuff is a little complicated for me




What you're looking for is a Nema-4X 1PH input 240V VFD.

Nema-4X is a dust tight enclosure, keeps the drive protected from shorting when in dusty environments.

1PH 240V input is the part that eliminates the RPC, it converts 1PH AC to 3PH AC. With that you can pull 220VAC from the wall socket and run the motor with variable speed.

For a drill press with a 120VAC motor you'll need to buy a new 3PH motor and a VFD for that motor. Some of the conversion threads go over that step by step.


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