New to me Bridgeport Mill

[Johnwa]

Re: missing R8 drive pin. My mill is missing it as well. There is a spot for it but I doubt one was ever installed While researching it, I found some debate on whether it is even desirable to have one. I don’t have any problem running mine without one, but it’s a smaller mill so likely less horsepower.

 

[Tom Kitta]

A lot of items can be got cheap and looking professional from places like Aliexpress and eBay.

Most of the stuff outline is easy fix. You can even look into simply converting machine to 1ph 240V See the frame of the motor it has now & I am sure for under $300 you can get a brand new 1ph 3hp motor to fit. Machine does not have a lot of other "connections" so it should not be a big deal.

 

[Susquatch]

Re: missing R8 drive pin. My mill is missing it as well. There is a spot for it but I doubt one was ever installed While researching it, I found some debate on whether it is even desirable to have one. I don’t have any problem running mine without one, but it’s a smaller mill so likely less horsepower.

I got the old broken pin out easily thanks to my wife. Yes, I can see why some people might not like it. But it is factory and R8 standard, so for the time being I'd rather get a small box of spare pins......

 

[Susquatch]

A lot of items can be got cheap and looking professional from places like Aliexpress and eBay.

Most of the stuff outline is easy fix. You can even look into simply converting machine to 1ph 240V See the frame of the motor it has now & I am sure for under $300 you can get a brand new 1ph 3hp motor to fit. Machine does not have a lot of other "connections" so it should not be a big deal.

Agreed. I'm in the process of pricing and sourcing parts now.

Replacing the motor is tbd. I think for now I'm gunna get a VFD and run it as is to evaluate the health of the mill. The right VFD can be moved to the other mill, but I don't want to sink a ton of money into fixing a machine I decide not to keep and then can't recoup the investment. Some stuff is a no-brainer though.

 

[Susquatch]

So I got the "motor certificate" from the seller......

Turns out its a receipt not a certificate. But the receipt clearly shows it was re-wired to 240V. So that mystery is behind me.

The receipt was for $1650 with no tax. That included re-wiring and new bearings. But it's still a small fortune for something they turned around and sold to me for $1800.

 

[Tom Kitta]

So I got the "motor certificate" from the seller......

Turns out its a receipt not a certificate. But the receipt clearly shows it was re-wired to 240V. So that mystery is behind me.

The receipt was for $1650 with no tax. That included re-wiring and new bearings. But it's still a small fortune for something they turned around and sold to me for $1800.

Wow, they ... paid ... 1650 to have a motor re-wired? For half that I could just send the motor to India, have it re-wired and sent back. I actually saw motors being re-wired in India when I was there - its a popular thing for locals.

For quarter of the price one could just get a brand new motor. Its not like its some special two speed motor or something.

If its 240v just run it off VFD. You can get a rotary converter later on. I would not change the motor to 1ph, not worth the Hussle. None of my large machines are 1ph.

 

[Susquatch]

Wow, they ... paid ... 1650 to have a motor re-wired? For half that I could just send the motor to India, have it re-wired and sent back. I actually saw motors being re-wired in India when I was there - its a popular thing for locals.

For quarter of the price one could just get a brand new motor. Its not like its some special two speed motor or something.

If its 240v just run it off VFD. You can get a rotary converter later on. I would not change the motor to 1ph, not worth the Hussle. None of my large machines are 1ph.

Yup, my view too.

You pretty much summed up where I'm at right now too. Shopping right now for a good VFD. Prolly end up spending a bit more than I should cuz I want to maintain maximum flexibility for down the road. But I won't go crazy.......

 

[Susquatch]

Anybody know what the standard motor shaft size is on a 2HP J2 Bridgeport?

 

[Susquatch]

Btw, the receipt for the motor rewind was fall of 2018. So it was done very recently. I'm guessing it was never even used after that.......

 

[YYCHM]

Anybody know what the standard motor shaft size is on a 2HP J2 Bridgeport?

https://www.practicalmachinist.com/.../bridgeport-2hp-motor-shaft-dimension-177497/

 

[Susquatch]

https://www.practicalmachinist.com/.../bridgeport-2hp-motor-shaft-dimension-177497/

Thanks. On that forum, they say that 1.179 is the correct size for a 2hp BP. My Hartford is 0.988. Maybe a scooch smaller - couldn't get a vernier in there perfectly square. Soooooo...... they are not the same.

There goes yet another swapping opportunity. (insert sad face here)

 

[Brent H]

Holy smokes! $1650 - that is nuts!!! A new - brand new - motor is about 1200 if you buy it from a middle man - yikes!!!

A 575 volt motor does not easily rewire to 240 volts - sort of a pain due to the way the windings need to sort out. - probably why the Cost - but - I agree with Tom, you could probably send the thing away and have it done much cheaper.

The motor for the Bridgeport variable speed is unique as it has a long shaft - the pulley on it moves with the change in speed to keep the belt aligned. I think it is like 7/8” diameter but 4 inches long.

 

[YYCHM]

Thanks. On that forum, they say that 1.179 is the correct size for a 2hp BP. My Hartford is 0.988. Maybe a scooch smaller - couldn't get a vernier in there perfectly square. Soooooo...... they are not the same.

There goes yet another swapping opportunity. (insert sad face here)

Were you thinking of swapping motors?

When I converted my mill to 3 phase the motor shaft on my $50 Kijiji find was a smidge to large to fit the drive pulley. Was a metric vs imperial thing. Not wanting to muck with the pulley I turned the motor shaft down on my lathe.

 

[Brent H]

@Susquatch - yes the 1.179” diameter makes sense but the two mills have different characteristics- check the parts explosion I put on the page - the Hartford you can adapt pretty easy because it does not need the extra long shaft.

 

[Susquatch]

@Susquatch - yes the 1.179” diameter makes sense but the two mills have different characteristics- check the parts explosion I put on the page - the Hartford you can adapt pretty easy because it does not need the extra long shaft.

This might be ok. I may not be able to swap motors, but if I can get a 220V 3Ph for the Hartford, I could use the same VFD for both.

I had also hoped that it could be used on my single phase 220Lathe, but it looks like that isn't gunna happen. On the plus side, it looks like TECO does make a unit for single phase motors.

 

[YYCHM]

On the plus side, it looks like TECO does make a unit for single phase motors.

Post a link please.

 

[Susquatch]

Post a link please.

Sorry, it's ATO, not TECO. Here is a link. Price seems reasonable given very few if anyone else does this. Can't vouch for quality yet and have not evaluated limitations.

https://www.ato.com/2hp-vfd-single-phase-input-output

Other hp units are listed on the same page too.

I'm considering a TECO single phase input three phase output L510 for both mills. That will allow me to evaluate the Bridgeport as is, but I'll have to get a 220 3 phase motor for the Hartford so I can evaluate it. Either way, the VFD will be needed.

 

[Susquatch]

Were you thinking of swapping motors?

When I converted my mill to 3 phase the motor shaft on my $50 Kijiji find was a smidge to large to fit the drive pully. Was a metric vs imperial thing. Not wanting to muck with the pully I turned the motor shaft down on my lathe.

Yes, I was thinking about swapping motors. I'm trying to evaluate both units without spending money on parts I won't end up keeping.

I would have probably trued up the pulley and bored it out instead of turning the motor shaft but there is almost always more than one way to skin a rat.

 

[YYCHM]

I would have probably trued up the pulley and bored it out instead of turning the motor shaft

But then the perfectly good (almost new) 2 HP 220v single phase motor with drum switch the mill came with wouldn't fit the pulley.

When I got my mill, I didn't have a 220V circuit and the motor was wired for 220V, but could be wired for 120V. After exploring wiring the motor for 120V it was concluded that putting a 220V circuit in was just plain easier. 220V single phase lead to.... hey I could go single phase 220V to 3 phase 220V with a VFD and have variable RPM for like $80...well that and a $50 used motor. Regrets... None. Haven't changed a belt since.

A single phase to single phase VFD was not an option when I was looking? Maybe @David_R8 can comment.

 

[Dabbler]

OK, Mr Susquatch, you got me off my butt... My motor shaft is .875 on both my First mill and my Hartford mill of the same vintage as yours... (I measured mine on the shaft instead of the ID of the pulley... )

My Hartford is 0.988

-- Perhaps a little measurement error? I've seen 3/4 shafts and 7/8 shafts and 1" shafts, but not .988... - 25mm maybe?

Try to remeasure on the shaft between the pulley and the motor, and look out for the keyway!