NEWLY-ACQUIRED JET 1236PS

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liveaboard
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Re: NEWLY-ACQUIRED JET 1236PS

Post by liveaboard »

I haven't had any come off all the way, but have had a small amount of unscrewing that ruined the job.

The chuck that came with my lathe has a set screw that fits into a shallow hole in the spindle. I never use it, but if there's a need it's there.
The hole is up when the spindle is locked, so it's possible to drill other backplate collars for a screw.

An idea if things ever get desperate.

The VFD is great for threading too. Even without adding a braking resistor, it will stop the machine fast enough to avoid the tool hitting where it shouldn't hit.
At slow speed of course.

Adding the VFD was the greatest thing to happen to this lathe since the original motor was rewound for 380V in the '50's
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Steggy
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Re: NEWLY-ACQUIRED JET 1236PS

Post by Steggy »

BigDumbDinosaur wrote: Sat Aug 22, 2020 12:17 amThe vendor is taking their time about righting this problem. I bought it through their eBay store, which means I could get unpleasant about it if they don't soon respond to my request for an exchange. eBay vendors don't like it when they get neutral or negative reviews.
Finally heard from the vendor, who said they will ship another backing plate to me. We'll see about that.
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Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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Steggy
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Re: NEWLY-ACQUIRED JET 1236PS

Post by Steggy »

liveaboard wrote: Sat Aug 22, 2020 4:46 amAdding the VFD was the greatest thing to happen to this lathe since the original motor was rewound for 380V in the '50's
Speaking of motors, the one that came with this lathe is a real boat anchor. It's a two horsepower, single-phase, split-capacitor unit, all cast iron, and around the size of an ODP NEMA 145T, but with a smaller shaft. I'm guessing it weighs around 75 pounds. It's definitely overkill for a 12" swing machine.

As part of converting to VFD, I will need to replace the motor with a three-phase unit. In the two horsepower range, both frame 56 and 145 are available, with the former being smaller in overall diameter and thus easier to mount. That said, a frame 145 motor will run cooler and last longer. Something to ponder...
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Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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liveaboard
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Re: NEWLY-ACQUIRED JET 1236PS

Post by liveaboard »

I have something like that on my drill press; it's supposed to be 1.5HP but it's the size of a truck. And as heavy.
I don't know when that drill press was made, but iron must have been really cheap at the time because they used a LOT of it.

I've discovered that HP ratings are a bit stretchy.
I have an old wood machine made in Belgium with 3HP motors.
My neighbor has the same machine, but 15 years newer. It has 4HP motors.
He had some trouble with it so I took a motor out and compared it with mine; they're identical in every respect, except the power claim on the plate.
Cooling is everything with motors.
Like a lathe, these wood working machines don't often require full power for long enough to melt the motor.
I only melted one so far.

I'd go with the big frame if you can. With all the time it will take to get it, mount it, wire it, the difference in price will be lost in the mail.
And with the VFD making it do things it probably wasn't designed to do, a little extra cooling surface could be a good thing.
armscor 1
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Re: NEWLY-ACQUIRED JET 1236PS

Post by armscor 1 »

Get rid of those inefficient, noisy, capacitor failing power sapping motors.
Replaced my 2 lathe and mill motors with 3 phase and vfd's.
Even put a 3 phase motor and vfd on my air compressor.
Full load current was 15 amps, now a mere 6 amps on the compressor with new motor.
Huge energy savings.
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GlennW
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Re: NEWLY-ACQUIRED JET 1236PS

Post by GlennW »

BigDumbDinosaur wrote: Mon Aug 24, 2020 12:52 am Speaking of motors, the one that came with this lathe is a real boat anchor. It's a two horsepower, single-phase, split-capacitor unit, all cast iron, and around the size of an ODP NEMA 145T, but with a smaller shaft. I'm guessing it weighs around 75 pounds. It's definitely overkill for a 12" swing machine.
The weight of that motor is what tensions the drive belt on that lathe.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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Re: NEWLY-ACQUIRED JET 1236PS

Post by Steggy »

GlennW wrote: Mon Aug 24, 2020 5:23 amThe weight of that motor is what tensions the drive belt on that lathe.
Actually, not.

There is an adjustable tensioning link for that purpose, which is not shown in the exploded view of the power transmission setup. It was something I had to repair due to the previous owner allowing the shoulder bolt securing the link to the motor base to become loose and wallow out the base's threads. I reworked the base so I could use a standard 1/2" stripper bolt in place of the original, whose threads had been damaged as well.

liveaboard wrote:I'd go with the big frame if you can. With all the time it will take to get it, mount it, wire it, the difference in price will be lost in the mail.
I found a source for a frame 143T motor, which has the same shaft size (7/8") as the frame 145T, but a slightly smaller overall diameter—that is the critical dimension in getting the motor to fit within the available space. I will have to bore out the motor pulley to get it to fit, and drill and tap some new mounting holes in the motor's base plate. Ironically, I will have to use someone else's lathe to bore the pulley...
And with the VFD making it do things it probably wasn't designed to do, a little extra cooling surface could be a good thing.
The motor I've selected is a TEFC inverter-rated unit. As a fairly general rule, it's best to not use a non-inverter-rated motor with a VFD, for reasons other than just cooling considerations.
———————————————————————————————————————————————————————
Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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GlennW
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Re: NEWLY-ACQUIRED JET 1236PS

Post by GlennW »

BigDumbDinosaur wrote: Mon Aug 24, 2020 11:46 am
GlennW wrote: Mon Aug 24, 2020 5:23 amThe weight of that motor is what tensions the drive belt on that lathe.
Actually, not.

There is an adjustable tensioning link for that purpose, which is not shown in the exploded view of the power transmission setup. It was something I had to repair due to the previous owner allowing the shoulder bolt securing the link to the motor base to become loose and wallow out the base's threads. I reworked the base so I could use a standard 1/2" stripper bolt in place of the original, whose threads had been damaged as well.
Interesting!

The previous owner must have added it. Mine relied on the motor weight, hence the cast iron 75 pound motor on a hinged base.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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Steggy
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Re: NEWLY-ACQUIRED JET 1236PS

Post by Steggy »

GlennW wrote: Mon Aug 24, 2020 12:54 pmInteresting!

The previous owner must have added it. Mine relied on the motor weight, hence the cast iron 75 pound motor on a hinged base.
It appears to be OEM. There is a tab cast into the motor mount plate and that tab was drilled and tapped to accept the shoulder bolt. The adjusting link also appears to be an OEM part. Next time I have the camera out I'll take a picture so you can see.
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Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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liveaboard
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Re: NEWLY-ACQUIRED JET 1236PS

Post by liveaboard »

BigDumbDinosaur wrote: Mon Aug 24, 2020 11:46 am As a fairly general rule, it's best to not use a non-inverter-rated motor with a VFD, for reasons other than just cooling considerations.
Geez, I just wired the shiny new VFD to the [very] old lathe motor.

If it melts, I'll make a post about it.
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Steggy
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Re: NEWLY-ACQUIRED JET 1236PS

Post by Steggy »

liveaboard wrote: Mon Aug 24, 2020 5:55 pm
BigDumbDinosaur wrote: Mon Aug 24, 2020 11:46 am As a fairly general rule, it's best to not use a non-inverter-rated motor with a VFD, for reasons other than just cooling considerations.
Geez, I just wired the shiny new VFD to the [very] old lathe motor.

If it melts, I'll make a post about it.
Oh, it will work. The question will be how long. :D
———————————————————————————————————————————————————————
Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
User avatar
Steggy
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Re: NEWLY-ACQUIRED JET 1236PS

Post by Steggy »

BigDumbDinosaur wrote: Mon Aug 24, 2020 12:40 am
BigDumbDinosaur wrote: Sat Aug 22, 2020 12:17 amThe vendor is taking their time about righting this problem. I bought it through their eBay store, which means I could get unpleasant about it if they don't soon respond to my request for an exchange. eBay vendors don't like it when they get neutral or negative reviews.
Finally heard from the vendor, who said they will ship another backing plate to me. We'll see about that.
Received another collet chuck backing plate. It gets a little tight as it nears the spindle shoulder but does fully seat.

backing_plate01.jpg
backing_plate02.jpg
———————————————————————————————————————————————————————
Music isn’t at all difficult.  All you gotta do is play the right notes at the right time!  :D
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