120vac, 3450rpm, 10.2a motor… is it possible to lower the amperage used?

Thread Starter

skeer

Joined Oct 28, 2022
58
So continuing from my previous and first post on here, I have a Chinese 5-speed drill press with a now bad motor. I have another motor that’s known good that originally powered a jet well pump.
It’s specs are: 120/230vac, 3450rpm, 10.? Amp, Brushed

OG motor is a 120vac 1600rpm 2.3a job, provided the stand and head will support the extra ~8lbs of this other motor I can get it to mount and work. However I don’t really want or need a motor that eats upwards of 10 amps.

Is there a reliable way to lower both the rotational speed and amperage required without tons of expense and work?
 

MaxHeadRoom

Joined Jul 18, 2013
28,761
So continuing from my previous and first post on here, I have a Chinese 5-speed drill press with a now bad motor. I have another motor that’s known good that originally powered a jet well pump.
It’s specs are: 120/230vac, 3450rpm, 10.? Amp, Brushed
If that motor runs on AC and is a brushed motor, then it indicates a Universal motor and is not really a good candidate for a drill press.
It operates in a run-away condition where rpm is governed by load.
A motor does not draw the rated current until loaded.
 

Thread Starter

skeer

Joined Oct 28, 2022
58
If that motor runs on AC and is a brushed motor, then it indicates a Universal motor and is not really a good candidate for a drill press.
It operates in a run-away condition where rpm is governed by load.
A motor does not draw the rated current until loaded.
Hmm I must be wrong on that part then. A well pump can’t really have it’s rpm based upon load
Its an older Doerr, model LR-22132.
I should really stop relying on memory for spec numbers.
1hp, 120/230; 17.8/8.9 amps, Cont duty

from what I can google these were commonly on 15-20gl air compressors from the late 70s-mid 80’s. Did they have brushless back then?
 

Thread Starter

skeer

Joined Oct 28, 2022
58
Had no idea inductions were older than like, idk the past 30 years? Lol.

Ok so speed control would be accomplished ideally by pwm or possibly a variac? I used to have one too crap, it was a big guy. I guess what I’m getting at is a typical voltage regulator wouldn’t be ideal for induction would it?
 
Last edited:

MisterBill2

Joined Jan 23, 2018
18,963
Indeed, the well motor is a 2 pole induction motor, about 1HP. And certainly not right for a drill press.
Induction motors have been around a whole lot of years, I had a used one one back in 1955. And I inherited a grinder setup that uses an induction motor mad in 1948. So induction type motors have been around a long time. They are cheaper to make and they last a long time, and they have a useful speed/torque curve.
A variable speed drive with a brushed motor would be good for a drill press because of being able to run very slow when needed.
 

MaxHeadRoom

Joined Jul 18, 2013
28,761
Had no idea inductions were older than like, idk the past 30 years? Lol.
N.Tesla came up with the induction motor late 1800's ! :cool:
Many have used ex treadmill DC motors and (MC2100) controllers for drill press etc.
Most 1ph AC induction motors do not control well above 1/4 HP especially in machine tool applications.
 

bassbindevil

Joined Jan 23, 2014
836
Some washing machines had motors with a 2 speed solenoid controlled gearbox; those are great for drill presses because you can change speed with the flick of a switch.
 

MisterBill2

Joined Jan 23, 2018
18,963
A two-pole 3450RPM induction motor is not suitable for most drill press applications. It is really not even readily adapted to variable speed operation with a VS drive package. And for a pump application the mounting is probably not right either. So the best move will be to swap it for either a 4 pole or a six pole induction motor rated perhaps 1/4 HP or even 1/6 HP.
 

shortbus

Joined Sep 30, 2009
10,049
And for a pump application the mounting is probably not right either
Again why? He said it was a jet pump motor and most of them are mounted with a base mount on the pump pressure tank. And the shaft is there after the pump is removed, if it was direct"C face " mounted. But many of the old ones used a belt drive to the pump.

While on the motor topic read this quote -
if this person is correct, then the load determines amperage draw
It works the same for your other motor argument about a motor with a driver.
 

MisterBill2

Joined Jan 23, 2018
18,963
There had been a comment about the inconvenience of changing speeds with the stepped pulley, and besides that, drilling in most materials seems to be better with the slower speeds, unless the fastest production speed is most important. The drive motor for the drill presses with a stepped pulley for speed selection was not face mount on any of the drill presses that I have used.
And I have never seen a belt drive jet pump for a water system.
 

shortbus

Joined Sep 30, 2009
10,049
besides that, drilling in most materials seems to be better with the slower speeds,
Most of these small presses are used by wood workers, and higher speeds are the reason. But the 4 pole motor is used because of the step pulley arrangement to get both fast and slow speeds from a small number of steps on a pulley.
 

Thread Starter

skeer

Joined Oct 28, 2022
58
Yeah this old motor was off a jet setup, and I believe is was in a belt drive however i highly doubt that was its original configuration.
Anyway that idea is out, too large and heavy.. the press would fall over too easily. Right now the game plan is to fab up some mount for a 120v, 1/2 horse, induction 2 speed washer motor.
This guy should work plenty fine for what I normally do.
 
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