Ian's Bridgeport mill

[Canadium]

You can see the motor is DC so Ian is poking around the rectification circuitry

Exactly correct! I did notice there was one loose wire inside. I suspect it got inadvertantly disconnected when the power cable was being removed. I will have to trace it and figure out where its supposed to be connected.

 

[Canadium]

For what it’s worth regarding the motor in the head, LN Electric is where I have had motors rewound. They did the motor on my old Williams horizontal mill and my excello. Both times a rewind and new bearings was around $400. The only place in Hamilton that would even give me a quote rather than try to sell me a new motor wanted $800.

Electric Motors Toronto | Swimming Pool Pumps Toronto & Vaughan| LN Electric Motors

LN Electric Motors sells and services electric motors and swimming pool pumps in Vaughan, North York and Toronto. Give us a call at (416) 661-5667.

www.lnelectric.com

Thanks @Rauce for the info!

 

[Canadium]

Just had another look at the wiring for the x-axis power feed. Studied the wiring very carefully, decided where the aforementioned loose wire should go and did the test. Voila the power feed now works!!! And I am a very happy camper!

 

[Susquatch]

It's been a little while. But I see your posts here and there so I hope you are doing better.

After reading this thread over again, I'd suggest the following approach: first and foremost, separate the power feed, DRO functions, and mill functions. That way you can debug them one at a time. After you have each of them working, you can reconnect them as appropriate having full knowledge of how each works.

I think your first task should be getting the mill portion wired up and working. The good news is that motor changes on the pulley version of the Bridgeport are MUCH simpler than they are on the VariDrive model.

For your mill, I believe you have 3 choices to make.

1. Have the motor rewound to 3 phase 220V and get a VFD to convert 2 phase to 3 phase.

2. Get a rotary converter or similar device to generate the existing power requirements.

3. Replace the existing motor with a new or old 220 3Phase motor and get a VFD to convert 2 phase to 3 phase.

I favour number 3 and that's what I did with mine. Mine is a pulley drive like yours but was 440V instead of 575.

The reasons I chose #3 is detailed in my thread on my new to me Hartford. But it can be summarized very simply. I wanted to get a VFD ready motor and a good VFD so I could get much wider and better speed control. This also leaves me with the original motor should I ever want to go back, and it makes my mill much more sellable if I have a stroke or similar life changing event. I am mid 70s so I have to be realistic about my future expectations.

In hindsight, I am glad I chose that direction. A good VFD and VFD ready motor are an amazing combination and a pure joy to use.

 

[Canadium]

Thankyou @Susquatch for the reply!

After reading this thread over again, I'd suggest the following approach: first and foremost, separate the power feed, DRO functions, and mill functions. That way you can debug them one at a time. After you have each of them working, you can reconnect them as appropriate having full knowledge of how each works.

The power feed has already been wired separately and found to be in working condition. The DRO was removed before I got it, only the scales remain and I was told will be useless so should be removed. It's the mill functions that have me stumped.

I think your first task should be getting the mill portion wired up and working. The good news is that motor changes on the pulley version of the Bridgeport are MUCH simpler than they are on the VariDrive model.

For your mill, I believe you have 3 choices to make.

1. Have the motor rewound to 3 phase 220V and get a VFD to convert 2 phase to 3 phase.

I'm told could cost about $400. Would require taking it to a distant shop.

2. Get a rotary converter or similar device to generate the existing power requirements.

By coincidence there is a transformer attached to the back of the mill that reduces 575V 3 phase to 120V or 240V single phase. If I'm not mistaken this could be wired backwards to take 220V 3 phase from an RPC to deliver 575V 3 phase. Just some capacitors and a pony 220V 3phase motor and I could have 575V 3 phase in my shop? Or is that mistaken? Since a lot of old industrial machinery around here seems to require 575V 3 phase including my mill this option appeals a lot. Of course the devil is in the detail.

3. Replace the existing motor with a new or old 220 3Phase motor and get a VFD to convert 2 phase to 3 phase.

I already have an old 220V 3 phase motor from a different model of Bridgeport ie it doesn't fit mine and would require an adapter plate. I am uncertain if this option would require completely altering the look of the machine since the motor might not fit the housing the same. I appreciate the advantages of using a vfd but don't don't want to change the original appearance of the machine by way of using a different motor. Also the motor I have is not VFD ready.

I favour number 3 and that's what I did with mine. Mine is a pulley drive like yours but was 440V instead of 575.

The reasons I chose #3 is detailed in my thread on my new to me Hartford. But it can be summarized very simply. I wanted to get a VFD ready motor and a good VFD so I could get much wider and better speed control. This also leaves me with the original motor should I ever want to go back, and it makes my mill much more sellable if I have a stroke or similar life changing event. I am mid 70s so I have to be realistic about my future expectations.

In hindsight, I am glad I chose that direction. A good VFD and VFD ready motor are an amazing combination and a pure joy to use.

So in summary I like all 3 options equally and can't make up my mind which way to go. I'm wondering if any one would know where I could get a suitable VFD ready 220V motor at an affordable price.

 

[Dabbler]

If I'm not mistaken this could be wired backwards to take 220V 3 phase

You don't quite have the right of it. When wired as it was installed, it converts the 575 3PH to 120 or 240 3PH - If you only use on leg of it, it is single phase.

When wired backwards, it doesn't do the thing you hope for. If you only power one of the 3 phases, it will heat up and not magically convert the output to 3 phase in any meaningful way (there will be potential on all 3 phases, but not *power* to those phases. The majority of the power input will be converted to heat by parasitic inductance on the *240V side*.

Also the motor I have is not VFD ready.

All of my motors on VFDs are conventional non-VFD motors. In milling and lathe work, we only use a portion of the horseopwer in continuous mode, and they work find in lathes and mills without the extra expense. I have a RPC and rarely use it.

 

[Canadium]

You don't quite have the right of it. When wired as it was installed, it converts the 575 3PH to 120 or 240 3PH - If you only use on leg of it, it is single phase.

When wired backwards, it doesn't do the thing you hope for. If you only power one of the 3 phases, it will heat up and not magically convert the output to 3 phase in any meaningful way (there will be potential on all 3 phases, but not *power* to those phases. The majority of the power input will be converted to heat by parasitic inductance on the *240V side*.

Perhaps I wasn't clear in my meaning. I meant if an RPC converting 220 single to 220 3 were connected to the transformer then you would get 575 3 phase out.

 

[Susquatch]

I'm wondering if any one would know where I could get a suitable VFD ready 220V motor at an affordable price.

If you want to use the existing motor as is you must go RPC. I don't think the transformer you have will work. As I understand it (keeping in mind that I am NOT a high power expert) single-phase power can be derived from a three-phase power source using a transformer, but a transformer cannot convert single-phase power to three-phase power. Converting single-phase power to three-phase power requires either a rotary phase converter (RPC) or a variable frequency drive (VFD). As of right now, I don't know of any VFDs that will convert 220 to 550. This is my understanding.

With the wonder of electronics, there may be other solutions here now or around the corner, but I am not aware of them.

Therefore, to use your existing motor, you only have two options - RPC or a rewind.

I bet you can find a better price on a rewind but don't have any recommendations.

A rewind will not achieve VFD ready. You will be limited to about 45Hz to 100Hz. Safe would be 50 to 75. Not really enough to make chasing it a no-brainer.

If you want good variable speed control 5Hz to 120Hz, you need a VFD ready motor. It will NOT LOOK THE SAME and YOU WILL NEED an adapter plate. In my mind a VFD ready motor is a highly desirable solution.

E-Motors has great delivery and good support. I was lucky and got a seconds motor (prolly a return but they guaranteed it), but I gotta tell you that knowing what I know now, I would buy a new one at full pop without batting an eye.

You will also need to make an adapter plate. It was way easier than I imagined. If I had to do it over I would use a rotary table to make it. But that assumes you have a working mill and a rotary table. So I did what I had to do. I used a cutting torch and a side grinder. It's not gorgeous but I don't even notice it anymore.

The mounting plate on the motor will take a box of some kind in the future for controls and master switch etc. Today it sits there looking ugly and..... I don't even notice it now.

Edit - I didn't see @Dabbler s post till I pressed submit. What he says complements what I said.

 

[Susquatch]

Perhaps I wasn't clear in my meaning. I meant if an RPC converting 220 single to 220 3 were connected to the transformer then you would get 575 3 phase out.

Assuming the transformer has 3 phase in and out then Yes. But not anywhere near the power level you need. That transformer was just used to create lower power for the other devices on the mill. Not to run the mill.

But I bet the transformer only has 220 single phase out not 3 phase. In fact it might only be 120 single out.

 

[Canadium]

If you want to use the existing motor as is you must go RPC. I don't think the transformer you have will work. As I understand it (keeping in mind that I am NOT a high power expert) single-phase power can be derived from a three-phase power source using a transformer, but a transformer cannot convert single-phase power to three-phase power.

I wasn't considering trying to change single phase to 3 phase through a transformer. I wanted to make an RPC that took the 220 single to 220 3 phase then transform to 575 3 phase. My "magic" is in the RPC.

Converting single-phase power to three-phase power requires either a rotary phase converter (RPC) or a variable frequency drive (VFD). As of right now, I don't know of any VFDs that will convert 220 to 550. This is my understanding.

With the wonder of electronics, there may be other solutions here now or around the corner, but I am not aware of them.

Therefore, to use your existing motor, you only have two options - RPC or a rewind.

I bet you can find a better price on a rewind but don't have any recommendations.

A rewind will not achieve VFD ready. You will be limited to about 45Hz to 100Hz. Safe would be 50 to 75. Not really enough to make chasing it a no-brainer.

Great point! I wasn't thinking about that.

If you want good variable speed control 5Hz to 120Hz, you need a VFD ready motor. It will NOT LOOK THE SAME and YOU WILL NEED an adapter plate. In my mind a VFD ready motor is a highly desirable solution.

The aesthetics are precisely what is holding me back. I would prefer to keep the original look of the machine and that is a big reason I'm leaning towards RPC. I guess its a matter of performance over aesthetics and which matters most.

E-Motors has great delivery and good support. I was lucky and got a seconds motor (prolly a return but they guaranteed it), but I gotta tell you that knowing what I know now, I would buy a new one at full pop without batting an eye.

You will also need to make an adapter plate. It was way easier than I imagined. If I had to do it over I would use a rotary table to make it. But that assumes you have a working mill and a rotary table. So I did what I had to do. I used a cutting torch and a side grinder. It's not gorgeous but I don't even notice it anymore.

Where did you get the steel for the adapter plate and how big a piece did you need?

The mounting plate on the motor will take a box of some kind in the future for controls and master switch etc. Today it sits there looking ugly and..... I don't even notice it now.

Edit - I didn't see @Dabbler s post till I pressed submit. What he says complements what I said.

 

[Susquatch]

So in summary I like all 3 options equally and can't make up my mind which way to go. I'm wondering if any one would know where I could get a suitable VFD ready 220V motor at an affordable price.

I think you need to jump in your car/truck and come pay me a visit. Nothing beats hands on to see what you might want to do, or not do. My shop is messy but its a barn first and a shop second and I personally prefer organized chaos over so clean you are afraid to get it dirty.

Maybe find someone running an RPC and go visit them too.

Just keep in mind that variable speed is much harder to do with an RPC. That said, the pulley choices built into your mill will do everything you want it to do.

My decision to go VFD instead of RPC was based on my desire to have variable speed tools and to stay away from high voltage. My future plans are to stick with 220V 3Phase and 1phase power throughout my shop.

 

[Canadium]

Assuming the transformer has 3 phase in and out then Yes. But not anywhere near the power level you need. That transformer was just used to create lower power for the other devices on the mill. Not to run the mill.

But I bet the transformer only has 220 single phase out not 3 phase. In fact it might only be 120 single out.

Transformer plate says 5kVA. Dunno if thats enough or not? I thought I read somewhere that 3 phase can easily be converted to single phase by just drawing on one of the 3 lines?

 

[Canadium]

I think you need to jump in your car/truck and come pay me a visit. Nothing beats hands on to see what you might want to do, or not do. My shop is messy but its a barn first and a shop second and I personally prefer organized chaos over so clean you are afraid to get it dirty.

If your shop is messy I bet mine is messier! I would love to drop by sometime to see what you have. Will PM about a mutually convenient time.

Maybe find someone running an RPC and go visit them too.

Just keep in mind that variable speed is much harder to do with an RPC. That said, the pulley choices built into your mill will do everything you want it to do.

My decision to go VFD instead of RPC was based on my desire to have variable speed tools and to stay away from high voltage. My future plans are to stick with 220V 3Phase and 1phase power throughout my shop.

That somehow sounds like very sage planning to me! Thanks!

 

[Susquatch]

I wasn't considering trying to change single phase to 3 phase through a transformer. I wanted to make an RPC that took the 220 single to 220 3 phase then transform to 575 3 phase. My "magic" is in the RPC.

Yes, I saw that in your reply to @Dabbler. And replied that your transformer won't work because it's too small.

Yes, an RPC will work but you will lose variable speed.

Great point! I wasn't thinking about that.


The aesthetics are precisely what is holding me back. I would prefer to keep the original look of the machine and that is a big reason I'm leaning towards RPC. I guess its a matter of performance over aesthetics and which matters most.

Ya, I get that. Get a nice paper bag to put over the motor...... Well, maybe not paper.....

Seriously, keep your original motor like I did and remember that you want to make nice things with your mill not sit there and look at it.

Besides, I bet my mill will be beautiful after I put a nice control box on the motor mounting plate. If not, maybe I'll make a red velvet bag to slip over the motor...... LOL!

Where did you get the steel for the adapter plate and how big a piece did you need?

10x10x0.5 at Metal Supermarkets (I think).

I cut it with an OA torch, cleaned it up a little bit with a side grinder, then put it on my lathe to recess it by 3/8 inch for the motor and cut the nose out for the motor. Then I drilled all the mounting holes on my old mill/drill.

 

[Susquatch]

I thought I read somewhere that 3 phase can easily be converted to single phase by just drawing on one of the 3 lines?

Yes, but not the other way around. In fact, you don't even need a transformer to do that. But the result will be an unbalanced load.

If you go out into the country and look at the overhead power lines, you will find that it's common to just split off one of the 3 phases to run a line to someplace with just one of the three phases. There won't even necessarily be a transformer there. Generally they do that so that one wire (one phase) serves one group of customers and the other wires serve other customers.

If you come and visit I'll show you an example right close by.

 

[trlvn]

@Canadium You might consider giving a call to PhaseQuest in Mississauga:

Phase Quest - Canadas #1 Transformers, Phase Converters, AC DC Motors

Phase Quest - Canadas #1 Transformers, Phase Converters, AC DC Motors

www.phase-quest.com

They sell both rotary phase converters and VFD systems. They're local so hopefully you could get some good information. I expect they're familiar with the issue of 575V requirements whereas a US-based outfit might not be. If you describe your situation and have the motor and transformer tags handy, hopefully they can lay out the options.

OTOH, they seem pretty expensive from a gander at the web site. YMMV...

Craig

 

[DavidR8]

The other place I'd try is e-Motors Direct. I've bought two VFDs and the three-phase motor for my mill from them and am very pleased with their pricing and service.

eMotors Direct - Canada's Online Source for Electric Motors, Gearing, and Controls

Delivering anywhere in Canada, eMotors Direct provides the best selection and knowledge of electric motors, parts, and accessories to get them what they need fast so that they can get back to business.

www.emotorsdirect.ca

 

[Rauce]

The other place I'd try is e-Motors Direct. I've bought two VFDs and the three-phase motor for my mill from them and am very pleased with their pricing and service.

eMotors Direct - Canada's Online Source for Electric Motors, Gearing, and Controls

Delivering anywhere in Canada, eMotors Direct provides the best selection and knowledge of electric motors, parts, and accessories to get them what they need fast so that they can get back to business.

www.emotorsdirect.ca

I can second that, I had great service there and picked up my order in person at the Oakville warehouse.

 

[Susquatch]

I can second that, I had great service there and picked up my order in person at the Oakville warehouse.

If you guys didn't catch it, that's where I got my VFD Ready Motor too. I was lucky to get a returned motor though. Regardless, I would have paid full pop. They were great to work with.

 

[Canadium]

Assuming the transformer has 3 phase in and out then Yes. But not anywhere near the power level you need. That transformer was just used to create lower power for the other devices on the mill. Not to run the mill.

According to https://www.inchcalculator.com/horsepower-to-kva-calculator/ the 5kVA transformer should easily handle the 1HP 3 phase motor on my mill?