# Bridgeport Voltage 3 phase to single phase



## Dadgumit

I have my first Bridgeport mill it is a 1hp 9x36 table.  what is the best way to run this mill on 220 voltage ? I have heard a bunch of ways !!  Thanks Dadgumit


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## CluelessNewB

A VFD would give you the ability to run your 3 phase machine on single phase 220 at full power.  It will also give you variable speed, overload protection and low voltage control (replaces a magnetic starter).    

If you have more than one 3 phase machine you might consider buying or building a rotary phase converter.   This will give you full power but it will NOT give you variable speed.  

The 3rd and least desirable is a static phase converter.  It will NOT give you variable speed and it will only supply about 2/3 of rated power.  These were common before low cost VFD's became available but I don't see much reason to go that route anymore.


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## JimDawson

+1 what CluelessNewB said.


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## jmarkwolf

I also installed a VFD to make 220V 3ph from 220V 1ph for my 1.5hp Bridgeport.

Works great.


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## alloy

I briefly considered phase converters when I got my 1HP Bridgeport but after doing some research I went with a Hatachi VFD and couldn't be happier. It's so nice just to reach up and change the speed by turning a knob. 

So plus one more vote for a VFD. You won't regret it.


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## Rangerjoe2

VFD ' S are the way to go.  I have one on my mill and lathe.


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## sdmuleman

VFD. Unless you have the parts lying around already you'll likely get close to the cost of a VFD trying to setup a RFC and a VFD is much easier to work with and takes up less room. 

Worth noting that the VFD is pretty noisy (electronically) though, so if you have a CNC machine or electronics around the machine (computers, radio, etc) you could get noise issues. Not likely to be a big problem, but something to keep in mind.


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## Karl_T

I think we're up to +5 on the VFD...

I suggest you make it REALLY NICE while you're at it.

A braking resistor will allow you to make your machine stop in under a second. If you're a cheap skate like me, power resistors off eBay work fine.

Remote forward/off/reverse switch makes it much nicer to run. I'd use the existing one on your mill.

I'd also suggest replacing the speed pot with a unit placed where its handy for the operator. The one on the VFD isn't sturdy enough to last.


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## alloy

Make that 6 on the VFD. 

I have the same mill and have a VFD on it.  It's fantastic, variable speed control at the twist of a knob, added an E stop switch, soft start and stop.  Soft reversing for ridged tapping.

We have a vari speed Bridgeport at work and it's only a few years old where mine is 52 years old.  I'm much rather use my mill than the one at work.  I'm actually trying to talk them into putting a VFD on the mill.  

You won't regret getting a VFD.


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## Smithdoor

My first Bridgeport mill I put a single phase motor on with 56C frame. Work great for long time till I sold the mill. The other way is to use a DC motor like find on a tread mill 

Dave




Dadgumit said:


> I have my first Bridgeport mill it is a 1hp 9x36 table.  what is the best way to run this mill on 220 voltage ? I have heard a bunch of ways !!  Thanks Dadgumit


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## sdmuleman

Only thing to be careful of with a VFD is using is too much for speed control. 

My post in this thread http://www.hobby-machinist.com/showthread.php/28595-Phase-Converter-BP-Series-1-2-HP talks about issues. Yes, I'm being lazy and not retyping....


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## gwade

I have the exact same mill - a 36" BP with 1HP motor.  I went with the TECO 1 HP with a variable pot built in (JNEV-201-H1).  I could not be happier but would like to add a reverse switch and emergency stop sometime.


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## metalmole

The Teco 1HP VFD, is the way to go....single phase 115 volt in 3 phase 1 HP  out and about $125, and about 15 minutes and you could be makin chips.....I love mine....its a no brainer....


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## jmarkwolf

Same here.

I've got a Teco on my J-head 12x42 1.5HP Bridgeport. 

220V single-phase in, 220v 3-phase out.

Works great.


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## Hamstn

Another plug for VFD. Even if I had 3ph power I would  be running a VFD just for the versatility it adds.


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## keyster

Another vote for the VFD.
I just got mine running.
The original switch is used to control the VFD.
I mounted the speed pot in the name plate.  Handy spot and an empty cavity behind it.
I will add the e stop when the button comes in.
I can run the motor from zero to 75 hertz to give me a little more speed range available for each belt step.


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## Winegrower

Here’s a vote for a simple static phase converter if you have multiple 3-phase machines.   I run my Bridgeport, my Kalamazoo saw, and my Powermatic PM2000 from a single 3 phase line.  (Not simultaneously).   I also have a Powermatic wood lathe that I control with a VFD, because rpm is so important moment to moment while turning.   

The VFD has to be somewhat customized for the particular motor in use, and should not have any switching inserted between a VFD and motor, so driving multiple machines from one VFD doesn’t seem desirable to me.  And of course where do you put the VFD so it’s accessible from all stations?

I have never come close to running out of power with the phase converter on any machine.


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## Winegrower

Plus, don’t fall for the VFD “zero rpm” idea.   The classic machines we have will not have “inverter ready” motors that can handle inverter switching transients, and can overheat at low speeds.


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## warrjon

+7 for the VFD.

I run my 3hp Lathe and 5hp mill from VFD's. I do not use the VFD for speed control. It is used for single to 3ph conversion.

If you do use the VFD for speed control you must keep the motor in its frequency/voltage curve, you do this by setting the motor parameters in the VFD


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## GDS12

Sorry, I know this is an older thread but I am considering using VFD's for my Enco (Bridgeport clone) as well as a couple of other machines.  Is there a simple stand-alone version of a nice VFD drive that doesn't require any fancy DIN rails or elaborate housings?  My mill is a 3 phase 2HP model so the ability to smoothly control speed would be nice...


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## JimDawson

Here is where I had my VFD mounted, just put it in place of the original motor switch.




I did some other mods and part of that was replace the VFD so this is where I have it mounted now, on the back of the electrical panel.  Don't panic, most of those cables have nothing to do with the VFD 




And the new VFD controls


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## GDS12

Thanks for the reply.  That looks like a nice and compact installation.  Very similar to what I was hoping to achieve.  As I read more about these installations I seem to come across many references to people changing motors in the process of these conversions.  Is it necessary to change motors as well?  I already have 3 phase power available (at least after I wire up a sub panel) and I really didn't want to go through the hassle of messing with the motor.  Is the issue that the old (cheap?) motors can't readily deal with a wider frequency range?  

Sorry for all the questions, but I am trying to figure out what the best way is to wire things up here...


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## JimDawson

If you stay between 30 and 90 HZ you should be fine with almost any motor.  I ran my old clone between 30 and 120 Hz with no problems.


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## alloy

Here is a pic of my VFD control panel.   I loosely designed it,  Jim refined it and made it on the mill he showed pics of.

A nice feature of that particular VFD we are both using is that it has a tachometer output.  Very handy since the head on my mill was specifically made for a VFD and you have no speed dials or belts to swap for certain speeds.


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## dlane

This is how I did my VFD , mounted in a box I made with a computer fan pushing air out the bottom . 
Plexiglass window


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## Dynahoe Dave

I set up my 1HP J-Head Bridgeport with a
*Mitsubishi VFD FR-D720S-025-NA*

Works great.   I found it on ebay for $125.   Made a remote switch & pot box and mounted it to the side of the head.


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## FOMOGO

I vote for a nice reliable overhead line shaft, with an economical wood fired boiler and steam engine. You kids and your new-fangled gizmos. Why when I was a boy, yada yada yada. For a single machine a VFD would be the way to go. Mike


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## markba633csi

Rotary phase converters are very popular and reliable, especially if you have more than one machine to power


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## GDS12

Thanks for all the feedback.  I like the fact that many of these have been made to almost appear OEM.  Is there a default pulley configuration when you go the VFD route?  Do you leave the pulleys in a state where something close to maximum torque is produced at the spindle (i.e. motor gear reduction)?

Sorry for all the dumb questions...

Gary


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## Dynahoe Dave

Mine came with a static converter, but I learned those reduce the power you can get from the motor.  I thought about setting mine up with a rotary.  But the power loss while on standby just annoys me.  With the VFD I got, the efficiency is at least 80% no matter what, worst case.  Also, at normal speed , you have full motor power.  Not that you often would need it.  Plus the extra noise I didn't want either.   And it does a nice ramp up to speed, and brake to stop.  AND I have the variable speeds.  I switch the belt for coarse  speed selection, then turn the pot on the VFD to get the speed I like.


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## JimDawson

GDS12 said:


> Thanks for all the feedback.  I like the fact that many of these have been made to almost appear OEM.  Is there a default pulley configuration when you go the VFD route?  Do you leave the pulleys in a state where something close to maximum torque is produced at the spindle (i.e. motor gear reduction)?
> 
> Sorry for all the dumb questions...
> 
> Gary




Back in the day when I had a change belt mill, I pretty much left it in the 660 RPM belt position.  Then adjusted the VFD as needed.  If I needed more torque or or higher speed, then I would change the belt/back gear as needed and use the VFD for fine control.


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## Fishchips

You can now get a 120v vfd that will give you 3 phase 240v.


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