CMI PM Motor

[coldspot]

Controlled Motion Inc.

This PM Motor, i got off E-bay $0.99

NOT what I expected.

Freight was $24.

28 Lbs!!!

Even after stripping off the "Control"

on the rear end, It's beyond my scales 5,000 gram Max.

The output? wires don't show anything when turned by hand.

So I took it all the way apart, nothing seems wrong or damaged?

 

[coldspot]

Some pictures of it

I hope to able to make use of it,

my first, New Hub" plan was a 5 blade that fit's this one.

[drdongle]

Cant read the name plate

tell us the specs

[ghurd]

You are testing for VAC, right?

G-

[coldspot]

Thats part of the problem

Name plate info is lacking any spec's

CMI, Controlled Motion Inc.

Plymouth, MN

Part No.   643-206

Model No.  ECM 643c

Serial No. P1032

Date Code. 1687

Customer No.

Revision level.

Thats it.

Nothing more

From Ohm Testing

Green wire to chassis ground screw

b&w= 3.7

b&r= 3.9

w&r= 3.4

El-Cheap-O multi meter seems to work better than

20 year old "FLuke 23", for Ohm testing??

On fluke

b&w= 6.4

b&r= 5.2

w&r= 4.8

Anyway thanks for looking

[Flux]

Is it really a permanent magnet, if that rotor was magnetic your tape in the last picture would be stuck to it. If it is magnetic then check for ac as Ghurd said.

I am not sure it is a pm.

Flux

[coldspot]

Was many days ago

Can't remember

So, I show test AC Volts, from ground to the 3 wires?

Will do later today

[coldspot]

Magnetic center rotor shaft

3 X 4 pc's

Yes magnetic

[drdongle]

The model number suggests that it is an ECM ( electronically commutated motor) type which has external 3 phase drive circuitry. If the rotor is not magnetic I'd say that conclusively that it is an ECM unit. If it is magnetic they you should get an AC out put.

[drdongle]

Then treat it as a 3 phase AC alternator and you will take output from the three leads to a 3 phase rectifier. Ground ( green) has no out put connection.

[Flux]

agreed.

The fact that different meters show different readings to ground suggests that there may be some electronic device to ground. Winding resistance is probably lower. To prove that it works, just short 2 of the 3 phase wires together and turn it, you will soon know if it is working.

Flux

[ghurd]

Set the meter to VAC and test any 2 wires (not to green).

I have a few similar to that.  

The magnets are all lame. Like microwave magnet lame.

Mine all started wired star. One or 2 or all would be better wired delta for sure due to low cut in speed.  A good use for the wife's new ceiling fan blades?

I think it'll be great.

G-

[coldspot]

Flux-

Meter readings

Never tested to ground

Ohm's was between wires

red

black

white

There isn't anything inside

Coils, lots of copper

thats all thats inside

All control stripped off

Testing AC Volts

reads overload

Have to try taping together to a small AC motor I got

to get a fixed reading

spinning by hand just overloads then unloads before a reading can be made

Thanks for looking, EveryBODY !!!

[coldspot]

OK,

Mounted hub, (5-1/2" pully)

When spun by place-n finger on outer lip

Meter @ VAC setting

Showed 11-12 VAC

Between any set of the three wires.

With having three wires

should I place a fullwave bridge on each or

can a diode, (little black schottky type #SD945)

be put on each wire?

If using a full wave bridge,

(two AC in's w/ Pos/Neg outputs)

I never understand just how to wire them

two of the three to one then

other wire to another, not using the extra

AC input on this one?

Couldn't this "extra" AC input

be hooked to another AC machine?

Or when doing "Bridge Rec's"

wire each wire to bolth AC Inputs

and use one for each wire?

yea crazy I am, BUT

I haven't let any "Magic Smoke"

Out of anything in years, lol!

Darn "Electrical Tech" deg was so many years ago, (21)

Not being in the industry

in anyway, sure lost it all. lol

Might have to fish out the books, (but remember the reading DULL)

Thanks

[Flux]

you need a 3 phase bridge, you can't do it half wave without the star point and it is not very clever if you could.

You need six diodes for the 3 phase bridge. Please yourself whether you use 2 single phase bridges or three.

If you use 2, connect dc terminals together + to + and - to -. use 3 of the 4 ac leads and leave one spare or join it to one of the others.

If you use 3 bridges, join dc as before, connect both ac of each bridge to a lead from motor. You now have 12 diodes connected in parallel pairs, works just the same.

Flux

[coldspot]

SWEET

Thanks Flux

I have been doing it right,

The bridge rec's, just makes

it nice when somebody else

explanes it and you see the light

that was there all along. LOL!

[coldspot]

Tested

By strapping tape of tiny little 115V AC motor to

large shaft off CMI unit

Quicky test clipped to a couple little bridge rec's

from computer power supply's

Fluke 23 set on V DC

Computer fan also in loop, (just for fun)

At about 60 RPM, ( I could allmost count it rotating)

24-25 V DC  !!!!!!!

At higher RPM's (little motor would just about get into sync with gen

but tape job sucks from different shaft sizes and gen about 50 times the size it

couldn't quite get there)

BUT, 50+ V DC !!!!!!!!

[coldspot]

Trying to keep in sync a bit more,

sad little sucker, (1.3A little motor, hey it hade switched cord

already on it, for easy testin,  lol)

This time it got to much higher RPM'S

I SAW,  112V DC     !!!!!!!!

SWEET

Great day,

Thanks for the help!!!!!

[coldspot]

OK, OK

I'm still excited a bit from yesterdays "tests"

BUT,

How many Watts might this get to?

Humm,,,...

P=IV

P=I2R

P=V2/R

No, NO that doesn't seem right?

Lets use 4 Ohm's, (each leg was 3.7,3.9,3.4)

Lets say 25 Vdc, (was at low Rpm)

V=IR

I=V/R

25. /4=6.250
    
6. 250x3=18.750, (three legs)
   
   

P=IV

18.750X25=468.750

That seems about there

CMI might be able to get 468 Watts

But as you can see my math skills are slim to say the least

Further testing needed for sure.

Thanks

Please jump in and fix my math if you know !

[coldspot]

CMI-

More testing, hand spinning

by finger against one of ceiling

fan blade holders,(5 blades installed).

OK this baby aint so babyish at 28 Lbs less prop.

But that means lots O Copper!!!

I could get her up to 15 V DC, with one finger. ( no load)

This will need more prop, ceiling fan blades @ 20" + about

5" or so for holder n hub area, with 5 installed

the light winds today, didn't even think about moving it.

O-Well

A tower that tuff is a ways off still anyway.

I'll just keep smiling about the easy higher voltages seen!

[coldspot]

More test-

Tonight getting my toys from truck

The wind was blowing pretty good,so

I figure, why not just get CMI and blades last.

OK, so I get everything else put away then

I go back out with a little 12 V DC Dash light

and a jumper set, with key and allen wrench.

I set CMI on top of truck Topper shell, wire up

the light, flip the shaft with thumb n finger-

A little bit of a glow in the light, GREAT I think!

So, I mount 5 ceiling fan blade set to the CMI and

grab it to walk out it the more open winds in the

middle of the road, (very seldom used dirt alley type

road out back of house next to train tracks).

I turned the unit into the wind and BOY that was about

the wrong thing to do.

The little 20" blades started spinning and very soon

the little light was VERY bright and I'm thinking about now

HOW do I stop this thing?

Only light out there was from the little light.

Girlfriend was calling me to dinner so I figure

I'll just move finger up to the 5 1/2" pully I

mounted the blades to.

I forgot about the bolts hanging about a 1/3" out

the back/bottom of the pully!

After getting clipped a dozen or so times,

I finally got my fingers to the outside

edge of the pully and slowed it down enough

to turn and yaw it to a stop.

Great test and remembering experience!

[willib]

wow i missed this?

[coldspot]

Hi willib

You didn't miss much just me getting

more stuff closer then switching to

another project.

But this PM motor does make good power.

Testing on a real lathe=

70. Rpm =  5.6VDC
    
120. Rpm = 8.85VDC
     
180. Rpm = 13.65VDC
     
420. Rpm = 32.9VDC
     
     

testing was done unloaded

Only Fluke23 hooked to wires.

RPM's I'm not sure about but the VDC

I was watching and even got a pic or two

The "who has the lathe" said "I think this is"

When he was telling me the RPM's

Also tested a "Treadmill Motor"

(2.5HP, 120VDC, 7100RPM)

60. Rpm = .55VDC
    
400. Rpm = 5.14VDC
     
     

This one will need geared up for any usefulness.

But was only $4.00 USD

And I got all electronics out of it

and most of the metal.

(Maybe a good motor for E-Bike, it does have

a good speed controller).