Bridgeport single phase motors ?
 

Ron Coffey writes:

Is there a replacement from a 3 phase to single phase motor for an
older J2 type bridgeport head? Around a 1 to 1/12 hp.

Surely if there is no direct replacement, it must be possible to make an
adapter plate?

Bridgeport single phase motors ?
 

Now I'm not sure if it is a J2 head. It is a 1 hp , belt pulley type not the
variable.
I have plans on making the rotary converter, but was just wondering what the
big deal and headache was to trying to find a single phase motor instead.
Thanks for the info and I would like to see the "adapter plate" idea that
Russ is talking about also.
"DoN. Nichols" wrote in message
...
In article ,
Ron Coffey wrote:
Is there a replacement from a 3 phase to single phase motor for an older
J2
type bridgeport head? Around a 1 to 1/12 hp.

Those motors are rather special to Bridgeports, and rather
expensive -- especially the pancake-style ones used for the variable
speed heads (and I think that the J2 is a variable-speed, and I *think*
also a 2HP motor, not 1 or 1-1/2 HP. When rebuilding the motor on mine,
I had to spend something like $800.00 just for a new shaft with a rotor
already installed -- with the old one as a "core charge". Consider the
complete motor as being significantly more than that -- and even more
wired for single phase. (I'm not sure whether there is sufficient room
in that housing for a centrifugal switch, which would be needed for the
single-phase version.)

The only time that replacing it might make sense is when the
motor is damaged, and has to be replaced anyway.

Instead -- why not *make* three phase for the Bridgeport?

You have two reasonable choices, starting with a 240V outlet in
your shop.

1) Build a rotary converter out of a larger three-phase motor.
(A 3HP would be plenty. A 2HP would probably do for the 1HP
version.) A google search for "rotary converter" on this
newsgroup will pick up tons of discussions on how best to do
this.

2) Pick up a VFD. This gives you the ability to vary the speed
of the motor as well. Do a search for "VFD" on eBay. Look for
one about 50% higher horsepower than your motor to allow for the
fact that is running from single-phase instead of three-phase.
There are a couple of suppliers often quoted when this comes up.
I remember "Dealer's Electric" as being one of them, but I
forget the other name. Someone else here will almost certainly
post it.


Option (1) would probably be cheaper, unless you are really no
good at scrounging. Option (2) gives you more control of the motor.
And I'll bet that it will be a lot cheaper than finding a single-phase
motor which will fit the Bridgeport. (Especially if the Bridgeport has
a variable-speed head, in that the motor has a *long* keyed shaft about
1" diameter which drives the fixed and sliding halves of the
variable-speed pulley.

Good Luck,
DoN.
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Bridgeport single phase motors ?
 

"Ron Coffey" wrote in
:

Is there a replacement from a 3 phase to single phase motor for an
older J2 type bridgeport head? Around a 1 to 1/12 hp.
tia,
Ron



I wouldn't bother. Go to http://www.dealerselectric.com and buy one of
their 1hp Teco Westinghouse VFD's for about $150. Else build a rotary
converter. you could instantly reverse the motor (tapping) if you did....

Marty

Bridgeport single phase motors ?
 

I made a adapter mount that allows me to use any 56C size motor. If I
recall correctly I also had to make a sleeve for the shaft.

stan

Ron Coffey wrote:
Is there a replacement from a 3 phase to single phase motor for an older J2
type bridgeport head? Around a 1 to 1/12 hp.
tia,
Ron

Bridgeport single phase motors ?
 

..

My Model M head has a nice 3/8" adapter plate. Simple and works good.
The motor is a Gryphon, from the UK I believe. The motor is quite
tall, maybe twice as "long" and 1/2 the diameter as the original
pancake would have been.

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXXXXXXXXX
On Wed, 06 Aug 2003 04:02:19 -0500, Richard J Kinch
wrote:

Ron Coffey writes:

Is there a replacement from a 3 phase to single phase motor for an
older J2 type bridgeport head? Around a 1 to 1/12 hp.

Surely if there is no direct replacement, it must be possible to make an
adapter plate?

Bridgeport single phase motors ?
 

Hi Ron
How about taking the guts out of the motor on the mill and just use
it for a jack shaft to hook an other motor to the mill?
GD

Ron Coffey wrote:

Is there a replacement from a 3 phase to single phase motor for an older J2
type bridgeport head? Around a 1 to 1/12 hp.
tia,
Ron

Bridgeport single phase motors ?
 

I may have to give that one some thought......hmmmm.
I guess since I'm almost finished with the rotary converter I should try it
first but I still like the idea of having only single phase in the small
shop (garage). A jack shaft is something I could do..... hmmmm.
thanks GD,
Ron
"GD" wrote in message ...
Hi Ron
How about taking the guts out of the motor on the mill and just use
it for a jack shaft to hook an other motor to the mill?
GD

Ron Coffey wrote:

Is there a replacement from a 3 phase to single phase motor for an older
J2
type bridgeport head? Around a 1 to 1/12 hp.
tia,
Ron

Bridgeport single phase motors ?
 

In article ,
Russwizinsky wrote:
I've made one and was going to put some plans for it and the required switch
modifications up on the inet for a small fee, I never got around to it yet.
The adapter plate is pretty simple, but you'll also need to hook up a relay so
when you click your switch off it'll actually turn all the power off to most of
the single phase motors. An electriction friend of mine tried for about a
month to do it with out having an extra relay in there but it just wouldn't
work out. I'll post some picks on my web site tommorow for you to check out.

If it is a dual voltage (e.g. 120/240V) single-phase motor, and
you're operating at the higher of the two voltages, there is a way to do
it with the standard drum switch for thee-phase motors. I've posted an
ASCII drawing of the wiring needed at least a couple of times -- once
within the last month, I think. No relays needed at all.

Enjoy,
DoN.

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Bridgeport single phase motors ?
 

It is a dual voltage motor, but I wired it up as 110. I don't yet have 220 in
my garage, and would like to sell the beast at a later time and purchase a
newer one. I couldn't find the spot on your web site with that diagram. I'd
be very interested in viewing it.
Russ
www.professorwiz.com

Bridgeport single phase motors ?
 

In article , DoN. Nichols says...

If it is a dual voltage (e.g. 120/240V) single-phase motor, and
you're operating at the higher of the two voltages, there is a way to do
it with the standard drum switch for thee-phase motors. I've posted an
ASCII drawing of the wiring needed at least a couple of times -- once
within the last month, I think. No relays needed at all.

I am willing to go farther out on a limb, and say it most certainly
can be done with a 120 volt motor as well, using the standard
three pole, center off, three position drum switch. I know because
I've done it on my 9" south bend, and others as well.

The essence of it requires, however, that there be seven or so
wires in the conduit between the switch and the motor. And
further that most of the leads in the motor be connected to.

The motor is basically two, two terminal devices. The run winding
is one, and the series combination of the start winding, centr.
switch, and capacitor, is the other. That gives four leads in the
conduit right there. The thermal overload protection gives two more,
because that has to interrupt the main power, and the green
ground wire is the seventh.

The drum switch has one pole that interrupts the run winding's
hot leg, and the other two poles are cross-wired to reverse
power direction to the start windings.

This sort of system is best wired up using liquid-tite conduit
between the motor and drum switch, because one can pull the
exact number of THHN conducors into place neatly. It works
with half inch liquid tite and makes a nice job. There is
never any need to employ relays or extra contactors for
machines like this.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Bridgeport single phase motors ?
 

In article ,
Russwizinsky wrote:
It is a dual voltage motor, but I wired it up as 110.

O.K. There was another followup to my article which described
how to do it with 120V -- though it does not open *all* wires to the
motor with the switch. It keeps the neutral (plus ground) connected,
which is reasonable enough for 120V wiring.

I don't yet have 220 in
my garage, and would like to sell the beast at a later time and purchase a
newer one. I couldn't find the spot on your web site with that diagram.

For the very good reason that I have never *put* it on my web
page. I mentioned ASCII graphics, which indicated that it was probably
in a usenet posting, and it was -- in this very newsgroup, at least
twice, and I suspect more than that. You could find those using google.

O.K. I've now made a quick-and-dirty downloadable schematic.
The URL is:

http://www.d-and-d.com/misc/PROJECTS...or-reverse.pdf

Note that it is in PDF format. You will either want to download
it to a file, and print that later using Acrobat reader, or view it and
attempt to print it from the screen. I don't use any wire names on the
motor, or terminal names on the drum switch, simply because these vary
from unit to unit. You're better off figuring out from the wiring data
on the label (often under the wiring plate on the motor, and stuck to
the inside of the drum switch housing. And the junctions between the
centrifugal switch, the starting winding, and the starting cap are often
buried inside the motor, with only two wires brought out as the ends of
the series connection. It really doesn't matter what order the switch,
cap, and winding are in -- in series is in series. :-) I drew them as
was convenient for me. Your motor may well differ, and it doesn't
matter.

The crossover wiring is often built into the drum switch --
either by the design of the wafers in a wafer switch, or as dark wires
permanently built into the switch, and rather hard to see. (I've got
examples of each, and I'm sure that here are others.) What I have drawn
would be sufficient to use with any 3PDTCO switch. The main thing about
the drum switches is that one input terminal connects to the same output
terminal in either FWD or REV position. The other two input terminals
connect straight through to the corresponding output terminals in FWD
position, and each connects to the other terminal in the REV position.
I've drawn the first one as the center switch section in my drawing, and
the other two are the top and bottom sections. In real switches, the
connect straight through in either position will probably either be the
first or the last of the three decsl.

Oh yes -- I forgot to draw in the safety ground, which is
connected from the safety ground at the outlet to the frame of the
machine tool and the motor, just to be sure.

I'd
be very interested in viewing it.
Russ
www.professorwiz.com

Enjoy,
DoN.
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Bridgeport single phase motors ?
 

In article ,
Stanley Baer wrote:

Ron Coffey wrote:
Is there a replacement from a 3 phase to single phase motor for an older J2
type bridgeport head? Around a 1 to 1/12 hp.
tia,
Ron

I made a adapter mount that allows me to use any 56C size motor. If I
recall correctly I also had to make a sleeve for the shaft.

Yours must be the kind with the motor above the belt housing.
Mine (the Series-I CNC) has the motor below the belt housing, and
anything longer than the original "pancake" motor would hit the ram.
(Of course, in my shop, I don't have enough overhead clearance for a
longer motor above the belt housing anyway. :-) It makes me glad that
this uses a quick-change spindle, and thus I don't need to get to a
drawbar. :-)

Enjoy,
DoN.

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Email: | Voice (all times): (703) 938-4564
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