Bridgeport motor questions

Hi folks
I have finally taken the plunge and bought a Bridgeport mill.... well the Adcock built version of it actually J2B with the vari-speed head,
the machine is 3 phase and I only have single phase here, so...it has one of the modern ad-on drives to the X-axis (110volt) and a coolant pump which I assume is 3 phase. It also has a modern Sino 3 axis DRO just fitted which I have asked to be supplied with a simple 13 amp plug fitted.
I can't see much of a reason to go down the rotary phase convertor route if I ignore the coolant pump and the X-axis motor, I'm just left with the main motor to worry about.
I have been told that the 2 speed Bridgy motors don't take kindly to being asked to run on inverters/converters, now, I assume that the motor fitted is 2 speed since it has the switch on the left side of the head?
Does anyone know if my info is correct, or has anyone on the "panel" gone down the inverter route for the main motor alone and can put me right?
I run my Myford 254 lathe on a Newton Tesla inverter set up and I would not hesitate to convert the Bridgy over to their stuff if the OEM motor won't be right on "pretend" 3 phase the only thing that worries me is the motor mounting, since it is flange mounted...is that unique to Bridgy's or can they be easily sourced in other brands? I have not asked Newton Tesla if they can supply a bolt on package for it yet.
I won't be fused if the Bridgy electrics become redundant provided I'm not missing something obvious here? It will perhaps be a bit ugly with all the different supplies coming on to it but since I have been quoted 800 notes for a rotary phase converter I'll learn to live with it and I don't want to have a another motor running noise wise if I can avoid it.
If I'm sounding a bit vague about the details it's because it ain't here yet I am working off pictures, it comes on Monday and the next challenge will to see if my Fergie 135's front loader will lift it off the guys trailer, should be fun and I'll take some pictures when we do it!
Cheers
Rich
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I (somewhere) have a CD from that stout fellow Stevenson with the manual for a Bridgie on it.
Since I no longer own the machine, you're welcome to it. Email me (at nigel dot eaton at gmail dot com) with an address and I'll pop it in the post.

I ran mine on a Powerwave static converter with no problem. In fact, I still have the converter. I should probably sell it... ;^)
--
Nigel

When the only tools you have are an X3 mill, a
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On Fri, 26 Jun 2009 22:52:40 +0100, Nigel Eaton

Or download them
http://bbssystem.com/viewtopic.php?tb
Charles
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First off all Bridgies have the switch on the side, many with spurious legends on them. If it 3 position it's a single speed motor, it needs three positions as it has to reverse because when you engage backgear the spindle goes the wrong way.
If it's a 5 position switch then it's two speed and you need a CONVERTOR as it needs 440v 3 phase
If it is the popular 3 position model then an INVERTOR will manage it.
Now the next problem. Many of these although made under license by Allballs and Shipley had the American motor fitted with 6 coils / 9 wires as opposed to our more technical advanced 3 coil / 6 wired metric framed motors.
They can still be run on an invertor but you need to alter the wiring in the connector box to suit.
You can do this yourself easily with a wiring diagram and an off the shelf inverter far cheaper than Newton Tesla can offer you one.
Newton Tesla will not be able to offer you a motor as they are very special to Bridgeport with an extended shaft to carry the variable speed.
A two speed can be wired as a single speed but requires the expertise of a rewind shop as they have to get the start points out from inside the windings.
John S.
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If it has got a vari-speed head i don't think it will have a 2 speed motor, all the Bridgeport's that i have seen or used which have a 2 speed motor have got the manual belt change heads. This is good news for you as its and easy job to run the machine from a 150 - 200 inverter. The 110v table feed unit with have a transformer in the control cabinet which will run off single phase.
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No, the 2J's, [ the variable speed models ] also had the two speed motor fitted, some were Brookes and some were Texas Prairie and Missed Spittoon Motors, Inc.
John S.
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On Fri, 26 Jun 2009 16:18:34 -0700 (PDT), John S

240-415V step-up transformer-> 415V inverter. Job done. run the auxiliaries off it as well, since they ought to be fed from a 415-110V transformer.
Mark Rand RTFM
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On Fri, 26 Jun 2009 15:17:29 -0700 (PDT), John S

Thanks for all that info John, I hoped it was going to be easy...sling the motor and bolt on a new one, job done.
Obviously I'll know the answers about the motor on Monday when it arrives.
I hope after that I'll just be looking for some advice on the best invertor to go for, one of things that I'm not clear on is.... can I set the parameters for max motor speed and soft start etc how do you interface with the thing?....laptop??
I think I'm one of those vertical learning curves!
Cheers
Rich
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Rich wrote:

Rich,
Inverters are pretty straightforward but some of the far eastern ones have chinglish manuals which can require sitting down in a darkened room with a bottle of aspirins!
Programming can usually be done from the front panel via a rather clunky interface without the need for a laptop. This is ok providing you are not going to be reprogramming every other day. A bit of a dirty trick is that quality manufacturers are able to reduce the price of their inverters by selling a base version with no controls on. In order to programme these, you need either to buy an operator panel (BOP = Basic Operator Panel) to match your inverter or you need to go down the laptop route. I tend to favour BOPs as they also tell you what is happening in normal use as well as programming.
You are also likely to need a voltage step up transformer to get from 240 to 425 volts. Wait and see which motor type you have, then decide.
A good source of transformers is a secondhand CONVERTER off ebay or similar. Even one with buggered capacitors is OK as you only need the tranny.
Order of events
get the motor details see if you need a transformer see if you can get one cheep then get the right sort of inverter (they are either 240 or 415 not both) Some suppliers sell a converting inverter. I've had no experience of these yet.
hth
Bob
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If it is a single speed motor than it's just a question of remaking the terminals inside the box. No real difference between any of the modern inverters, they are all a muchness, down to availability and personal choice.
Yes you can set min speed, max speed, acceleration [ soft start ], braking, max amps for overload etc, etc.
It's all done from the simple keypad on the front of the invertor. They have what is called functions which is a posh name for parameters and as you prees the keys they work thru one at a time. most entries you leave as stock and it's only a few you need to change but they depend on make of inverter. Whan you get sorted give a shout and someone will talk you thru it.
I have spreadsheets for many of the common inverters IMO, Yaskawa, Fuji, Telemechanique as we used to fit many of these.
John S.
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wrote: <<<SNIP>>>

made
If it's low-off-high I make that a dual speed motor
AWEM
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Andrew Mawson wrote:

Perversly Andrew I think this makes it a single speed motor which has to be reversed when low gear is engaged in order to keep the spindle turing the right way.
Bob
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On Mon, 29 Jun 2009 20:35:45 +0100, "Andrew Mawson"

Andrew
The way I read John's post, the simple switch means that the low postion just runs the motor in reverse for the back-gear?
Please go easy on me.....I have never actually seen a Bridgeport under power...including this one!
Cheers
Rich
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Andrew Mawson wrote:

My BP has a single speed motor and has a 3 position switch marked 0, 1, and 2. 0 is central and off, 1 is one direction, and 2 the other either side of centre, so the 1, 2 positions are switched when going to/from back gear to correct the rotation direction. I have a 2 speed motor for a BP and that has a 5 position switch. All consistant with the various BPs I've used in the US and UK over the last 30 years IIRC.
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On Tue, 30 Jun 2009 00:19:01 +0100, Rich
<snipped about 3 pages worth>

Low Range refers to the spindle speeds (not motor speed) when back-gear is engaged. So High Range for normal running, Low Range for when you engage back-gear, as the back gearing actualy reverses the drive to the spindle, so the switch changes the motor direction otherwise you'll be running all your cutters in reverse!
Peter
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On Fri, 26 Jun 2009 22:44:30 +0100, Rich

Sorry for the delay in this saga, I was rudely interupted by having to go to work.
I now have the problem cracked, the clues were in JS's post about the motor wiring and another John at Newton Tesla who have provided me with a Mitsubishi inverter and and one of their control stations.
On the motor plate there are two choices for wiring, "hi-volts & lo-volts" the motor as it was was hi-volt (delta I think) and it needed to be changed to star. Since all the wires are numbered, it was a simple job (even for me) to change it over. For the record if anyone cares to look back at this post on my motor what I did was:
Connect No's 4-5-6 together.
Then 9 & 3 to one phase
8 & 2 to one phase
7 & 1 to one phase.
I had got a length of 4 core cable on a scrap chit from work for the 3 phase side (3 phases + earth) and some advice from the sparks, then followed the wiring diagram for the inverter, quite simple really and also hooked in the remote station that gives full speed control, jog, forward & reverse. The inverter gives a read out of frequency it's programmed to give a max of around 58hz and the jog function is 5hz so the spindle speed is ultra low.
I hooked the single phase up to 13 amp plug and got the wife to switch it on so I was in no danger.........
It all worked perfectly apart from the rotation so I shut down waited for the recommended 10 mins and changed around two phases, job done.
Next things that came to light were that I couldn't select back gear on the head, this proved to be that the lever that pulls out the detent plunger had sheared the hook off the end, (could be I did that when lifting it off the trailer so I'll give the seller the benifit of the doubt) I phoned Hardinge in the hope that it would be as cheap as chips to buy a new one and it not to be worth the time to make a new one.....of course it is the old type and to change it to the latest version would have cost about a 100 notes....I declined of course.
The other problem that had me scratching my arse was the vari-speed seemed to be working in reverse, turns out that the nugget that changed the spindle bearings wound the chain on to the shaft the wrong way, only took a couple of minutes to sort out but annoying all the same.
There remains a problem in there that when it is on max speed it sounds like one of the pulleys is hitting the cover, that one will need to wait a while until I whip off the motor and cover to have a look at what's going on.
I am going to remove all the native Bridgy electrics and put aside incase I ever sell it on, I will run the X-axis drive from a 110v transformer and the Sino DRO is a straight 13 amp plug-in.
Thanks to all who chipped in I now understand the wiring for the flux capacitor..... it now makes sense although if the wires had not been numbered then I would have been f*cked...... and a special thanks to Nigel Eaton for the manuals on CD, like I said Nigel if you are heading this way give me a call and pop in for a visit.
Cheers
Rich

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