Bridgeport motor conversion - buckaroo article

I remember seeing an article in one of the buckaroo mags where they converted a 3 phase bridgeport to a 220 motor. Does anybody have that issue? or any tips to help?

 

Well first off most bridgeports have a 440 220 motor to start with.. They prolly only converted it to single phase. Some of them had really wierd motor shafts. If I was you id do a google search on a phase convertor. This will allow you to convert single phase to 3 phase and all around its a better deal.
Dave

 

yeah, i think a phase converter is the way to go....i just got mine running a week ago....only took a few minutes to wire up

Zach

 

ill have to find it i belive it was in a rodders digest almost 2 years a go and it was done by adaptin a single phase motor in place of the three

 

thanks, the machine we are looking at is priced right, however the motor may be going out. We also do not have 3 phase at our shop, so swapping motors would kill two birds...

 

it is in rodders digest aug 2005 pg74

if ya want a photo copy just drop me a pm and ill send it to ya

 

AS already mentioned - the bridgeport motor is a "special" in terms of shaft configuration - maybe that's what the article was all about. If so make sure the motor you get will be able to run both directions - backgear runs opposite direction as the direct drive so you gotta get a motor that'll work both ways.

I know you didn't ask, but if it were me - I'd KEEP the bridgeport motor - toss some new bearings in it if needed. Do yourself a BIG favor and build a RPC (rotory phase converter) nothing more than a glorified 3 phase motor LARGER than your biggest LOAD(tool) motor and wire your shop for "3 phase". The thing is IF you're sticking a mill in your shop you are likely gonna stumble across MORE cool stuff as time goes on and odds are that it's gonna be 3 phase - so why fight it - take the plunge now - I guarantee you'll never regret it.

BTW there are better phase converters than the old rotary - but the rotory's are stupid simple and dead reliable - and with a little effort work pretty darned good.

Food for thought anyways

 

I run mine off a phase converter and there's been no issues. I can't imagine what you'd be doing to be be able to notice a power decrease from the stock motors. Here's a DC motor swap someone done, which with a DC motor controller can make any non-variable speed B'port into VS. Mine is the stock B'port VS with the crank dial, if it weren't I'd convert it, I wouldn't want one without variable speed. Good luck.

http://truetex.com/dcdrv.htm


.

 

I've run a home brew rotary phase converter for years. Beats the hell out of the "static" phase converters. Neighbors (or the wife) have never complained about messing up the TV or radio or anything else. The addition of some balance caps will optimize them quite a bit. I run ALL my machines off the same system (less my Pullmax which is 480v) - Mill, bandsaws, lathes - so long as the converter motor is BIGGER than your largest machine - there will be no issue for "size".

 

I'm in the same boat...
I just picked up a Bridgeport myself (my dream machine!), except mine is 550 volt.
I too am somewhat interested in swapping out the motor for a single phaser. However, I wouldn't mind rockin' a phase converter - I'm kinda partial to keeping some things original though - but I really don't know how to deal with the 550 volt issue.

 

Don't worry about keeping it original. Take a 3/8 alum plate mount 1 ph motor to it. Having trouble uploading my photos.





Ago

 

A VFD would be another way to go. You can run the three phase motor off single phase power and you also have variable speed.

 

I am leaving in a few minuites on a six-hour trip to pick up a three-phase Millrite milling machine. I have a VFD, but don't know how to hook it up. I may change the motor...

 

I agree a VFD is the ONLY way to go you can get them in almost any combo needed they don't allow torque loss and you have variable speed. The prices arent that much higher than phase convertors and less than rotary.

 

I agree. When I installed mine I used a small Hitachi unit. There are more parameters than I use in that little thing...Start up speeds, stopping speeds. Variable speed, etc. It works great. I wired it into the original drum switch and I still use that to start the machine, reverse it, etc.

-Scott

 

How much do these VFD s cost and where is a good place to purchase?





AGO

 

Trying to upload photos






Ago

 

Ago - that looks sweet!
What are the specs on that motor?
...And the original switch still runs FWD & REV?
Awesome.

Coincidentally, I was just looking at similar setups on http://truetex.com/dcdrv.htm

 

Jug,

It is a 11/2 HP 1 ph. 1725 rpm 110 VAC type 56 frame. the switch works fine, For.- Rev. the switch is mounted on the motor base plate, if it was mounted horizontal. The motor is screwed into the alum. plate with the screws that hold the case together. been using it this way for 20 years.


Ago

 

I think I bought mine off of EBAY. It's a small Hitachi, but there are other manufacturers. Any industrial supply should be able to source them, especially those in the electro-mechanical field. These are basically industrial motor drives. I think on the low end you're talking about a couple of hundred $$. PM me if you need more detail, and I can look up the model of what I'm using. For reference I have the B'port in my home garage, feeding it with single phase 220V. The VFD gives me balanced 3 phase 220. The mill is a step pulley machine and I think it's 1 or 1 1/2 HP.

-Scott

 

For a easy start app like a mill a static converter is fine ,around $150. Got one on my 1.5 HP vairable speed B/port. Hard starting/heavy loaded things like air comp and big clutch-less lathes ya need a rotory. Got a 18"+ swing clutch-less lathe with a 16" chuck that is one HARD starting mother.

 

I bought a single phase 220 reversible motor from WWGrainger, I can get the part number if you like. I installed it on a Model J Brigeport with an adapter made from the center of a Chevy dually truck rim. Instead of wiring the motor for CW, or CCW, I extended the wires to the reversing switch, and can run it either way. Total cost was about $300 several years ago.

 

I just looked at drives www.driveswarehouse and found a hitachi model L100-007mfu for $199 it converts 115 1ph to 230 3ph 1hp. I also noticed they had wiring instructions that might help you out Richard D.

 

I'm horrible with wiring and I was able to set mine up. Wired it to the drum switch on the motor so that still works to operate the machineand was able to program some of the operating parameters that I would need. I set the ramp up time, slow down and stopping time, max power out and min power out. I think I go down to 45VAC and up to 90VAC so I have some speed control. The VFD works nice when reversing for tapping. You can reverse on the fly and the drive controls slowing the motor down-stopping-starting back up reversed.

-Scott

 

Here is a link to an earlier thread on this same subject:

http://www.jalopyjournal.com/forum/showthread.php?t=246543&showall=1

 

I got an Allen Bradley 1336 For $80 on Ebay.

 

Yea AB is good stuff used one at work to hook up the cnc mill I use. I used to have a rotogen right behind my workcell, noisey bastard would kick on and scare the shit out of ya.

 

you have 2 choices if you want to keep original motor;

a step up transformer to 550 volts.....

a rewind shop can alter the motor to run at a lower voltage...

 

Can they change a three phase to single phase?

 

http://www.homemetalshopclub.org/projects/phconv/phconv.html