Help fitting 1.5HP Newton Tesla motor to Union Graduate.

[Brian W]

Good evening All,

I recently obtained an old Union Graduate that I am refurbishing. I have purchased a 1.5Hp 3 phase motor and inverter package from Newton Tesla. I have the lathe stripped out and am preparing it for painting. Whilst I am doing this I wanted to send the motor plate away for re-drilling the mounting threads, however I do not have any measurements for where they need to be. Has anyone fitted this package before and can give me the required measurements?

Thanks

Brian

 

[flh801978]

I have done this many times
mount your old motor on the base whilst its in your hand, rather than in the pedestal

place the base on a sheet of card and mark where the pulley is and mark round the base also
then remove old motor and place new motor on and try and get your pulley to line up with where old motor was.
then mark through your mounting holes and drill

This may not be the end of it though as sometimes the motors to big to go into the pedestal in the correct position

Ian

 

[Brian W]

Hi Ian,

Oh my what a simple solution. I can't believe I couldn't see it, thank you, I shall hopefully get to try it out this weekend as long as SWMBO doesn't have other plans!

Thanks again,

Brian

 

[Sheptonphil]

Hi Ian,

Oh my what a simple solution. I can't believe I couldn't see it, thank you, I shall hopefully get to try it out this weekend as long as SWMBO doesn't have other plans!

Thanks again,

Brian

SHMBO's ALWAYS have other plans

Sometimes they just let us have out own way, so we think we control the schedule.

Phil

 

[PeterCh]

Hello i just bought Graduate Union lathe and next step is buying new motor with vfd ..
i want 1.5 hp 6-pole . Would it fit inside :?: i got email from Newton Tesla and they state that this motor would not fit. Did anyone here got experience with 1.5hp 6-pole ?
Regards

 

[CHJ]

Hello i just bought Graduate Union lathe and next step is buying new motor with vfd ..
i want 1.5 hp 6-pole . Would it fit inside :?: i got email from Newton Tesla and they state that this motor would not fit. Did anyone here got experience with 1.5hp 6-pole ?
Regards

Without knowing anything about the details of relevant motor sizes in relation to your lathe I can tell you that in my experience a slow speed 6 pole motor will be considerably bigger diameter than a standard 4 pole unit.

If you have a vfd why do you need a slow speed motor, surely with the combination of existing pulley options and 4 pole motor you will have a slow enough speed with adequate torque.

 

[PeterCh]

Hello thanks for reply. I just quote one article :


..."One tip is to employ a slower motor, a 6-pole one running at 960 r.p.m. (or even an 8-pole at 720 r.p.m.) rather than the more common 4-pole 1420 r.p.m.. These speeds assume a European 50 Hz supply, motors in the US, being fed with a 60 Hz current, run faster, their "normal" 4-pole motor speed is 1700 r.p.m. Oddly, against what would seem to be common sense, a slower motor helps because the inverter (at least with vector drive) will hold a nearly constant torque from minimum speed up to its normally rated top speed. Beyond the marked maximum power remains constant but, unfortunately, the all-important torque falls off. Hence, doubling the speed of, say, a 0.5 h.p. 720 r.p.m. motor lets your set up act just like 1 h.p. 1420 r.p.m. motor. A disadvantage of the 1 h.p. 1420 r.p.m. motor is that slowing it down reduces the power (power = speed X torque) and the motor has no way of increasing torque to compensate for this. The result is that, with inverter control a 3-phase 720 r.p.m. motor will always have the same or better torque than a 1420 r.p.m. type together with the same or better power output. It's best to avoid cheaper 2-pole 2800 r.p.m. motors (3600 r.p.m. in the US) as they have little torque and slowing them down means a significant loss of power"

I am kinda beginner regarding to motors ..anyway i found out that metric 0.75kw 6-pole motor would fit graduate (B3/90s frame says 312mm lenght of motor .. but i just saw youtube movie when person states he has graduate union "short bed" with 1.5hp 6-pole motor inside. But he dont respond to msg. so i am looking for information here.
The 1.1kw 3 phase 6-pole motor sits on B3/90 L1 frame which means 337mm lenght of motor.
Once i got all info and go for proper motor i would make photos and movie of my setup and upload here !
Thanks for help. Kind Regards

 

[Retire2004]

Hi Brian,
I agree with Chas' comments regarding motor speed, a 4-pole motor should be fine.
The normally accepted method is to use only 3 of the 4 available pulley ratios (i.e. the three biggest pulleys on the spindle should be aligned with the 3 biggest pulleys on the motor). This means that the motor can be moved outward towards the access door by an amount of 1 pitch (approx. 15-16mm) the two smallest pulleys (on motor and spindle) should therefore no longer be used, or even removed by machining away if you want to be that fussy. This creates a little more room for the motor within the body casting. Theoretically, a slightly longer belt may be required, but this is partly compensated for by the higher frame size of the replacement motor. If you intend to replace the spindle bearings, this can be addressed at the time and the correct size belt fitted. Good luck with your project!
Regards
Tudor