Best use for this motor?

[mickeyf]

Another PSC motor (Fuji Electric, very solid looking) followed me home as part of a collection of odds and ends. This one claims 1700 rpm, 13.1Amp at 120Volts, 550 watts output - which I figure to be approximately 3/4 hp. It is the type with symmetrical windings (per ohmmeter test) and I have run it both CW and CCW by switching the input. The most interesting thing is that it came with a magnetic brake which releases when power is applied. This means that although it is single phase, by powering the brake simultaneously with the motor with a center off DP switch it can switch direction as quickly as I can flip the switch.

Now I'm wondering what to do with it. If I had a smallish lathe (like 9") it might be useful, but all my machine tools have suitable motors already, except perhaps the drill presses, but I don't see it making any sense there.

What would be a useful thing to do with a motor of this type and size? Some kind of gadget I could build? Suggestions?

[J Tiers]

The thing about those is that their speed regulation is not very good compared to a regular induction motor. So the application would ideally be one that does not need good speed stability.

While it might not be a good unit for a drill press, the simple reversing might be an advantage for tapping. How about a dedicated tapping machine?

[chipmaker4130]

13A at 120V should be a whole lot more than 550W. Maybe 1550?

[mickeyf]

Maybe 1550?

Yes, I calculated that also, but that's what the label says. It does say "output" not power consumption.

[Mike Burch]

13A at 120V should be a whole lot more than 550W. Maybe 1550?

I would imagine these things have a particularly horrible power factor.

(As you probably know, anything inductive running on AC will have the current out of phase with the voltage, so the actual power produced will be less than that calculated by simply multiplying volts by amps.)

[JRouche]

Yes, I calculated that also, but that's what the label says. It does say "output" not power consumption.

yeah, I thought what? Then oh, its Fuji Electronics. Always output shaft. No sim-leading. JR

Edit: Not "sim-leading"

Dysldlex a lil. Miss-leading is what I meant.

Nice article on split phase (cap also) electric motors and the other types of small electric motors. JR

https://www.beckettcorp.com/support/...to-psc-motors/

[J Tiers]

I would imagine these things have a particularly horrible power factor.
.........

Most PSC motors can have a power factor near 1.0 (the best) at full power. So probably not a bad PF. Most every motor has the worst when idling, when it can be 0.1 to 0.2, which is very low.

[darryl]

Sounds like a motor for a fairly large garage door system. It might not like continuous operation over time because of low efficiency. Maybe run it for awhile in either direction and see how fast it heats up. If it gets really warm quite quickly, it might not be suitable beyond a few minutes at a time. If it stays quite cool, that would expand its potential uses.

It can make something open and shut, go up or down, side to side, or back and forth. Up and down is interesting, could be used with a worm gear drive to run a platform up or down a tower. Set it up as a winch. I kind of like the elevating platform, as I'd like to rise above the ground sometimes and take a look around. I don't suppose something like that would be allowed-

There are few ways I can think of to use this motor appropriately in one direction only. Not that you couldn't of course.

Perhaps it could be used to animate a Christmas display- make Santa stand up and wave, then sit back down. You can use it to run a fan when you want to choose the direction of the air. Cold in summer, warm in winter kind of thing. A lot is going to depend on how fast it gets hot. If moving air can cool it enough, it might gain a continuous operating status.

Here's a use, for those who still have a mailbox- a cable loop driven by the motor first opens a door on the side of the house. A life-size likeness of grandpa comes out and moves across the front lawn and stands there like a sentinel, waiting for the mailman. He's probably holding the mailbox in his hands. When he detects that mail has been received, he turns around and comes back in. In a variation of this, you could animate some kind of halloween figure-

Every idea I've had so far means using a gearbox. I'm trying to think of how you can use its rated rpm directly, and where you'd use both rotation directions.

[mickeyf]

. It might not like continuous operation

It apparently came out of some sort large paper guillotine machine - This thing was already disassembled before I saw it, but it had (and I also got) a very heavy blade such as you might find in a metal shear, maybe a couple of feet long, and a gear box with cams triggering micro-switches, and an acme screw not quite long enough to raise and lower the table of my large drill press. I think it was meant to run more or less continually. But yes, I'll see if/how it warms up.

I did think about a tapping machine. What I'm stumbling over here is how to gear down the speed enough. I suppose making a worm gear would be a good project, but a ways in the future at this point. I like the Halloween type display ideas, but those are also down the list behind a few more practical get-to-its.

[Doozer]

It might not have the torque,
but I am always on the lookout for
single phase motors of high quality
that DO NOT exhibit the single-phase
cogging and vibration that is inharent
in single-phase motors most of the time.
I have a 1/6 hp GE motor on a small drill press.
It is sooo smooth, not a trace of single-phase
cogging and harmonic hummm.
It makes the drill press a pleasure to use.
Things like surface grinders especially need
a good single-phase motor (or a 3 phase motor).

--Doozer

[mattthemuppet]

my usual response:

1) spiked portcullis
2) squirrel catapult

[I make chips]

Oh no,, Matt is gonna get me watching squirrel launcher videos again. There goes an hour.

[mattthemuppet]

yeah, but you'll be happier at the end of it than at the beginning

Tempted to make one here but houses are so close together I might accidentally hit a neighbour's child playing out in their yard. Imagine how traumatic that would be, for both of them?

[Mike Amick]

Nothing to contribute, but I find it amazing that a steel armature spinning at 1700rpm can instantly go the other direction.

It's like rubbing momentum into physic's face. It's like .. grabbing your crotch and saying .. "Here's your momentum"

[mickeyf]

Not quite instant - but less than a second. And yes, all that energy must go somewhere....
I used a center off 2PDT switch. So power to the motor is cut off more or less at the same time as the power to the brake. It must take some number of milliseconds for the brake, powered by mechanical springs, to actually bring the motor to a halt, and some further amount of time for the motor and brake to be re-energized the opposite way when the other set of switch contacts connect.

So what happens with a 3 phase motor when it is "instantly" reversed? (I can imagine the magnetic fields needing a visit to the chiropractor...)