Author Topic: 180v dc motor (Read 4645 times)

fordman · « **on:** February 02, 2006, 11:30:08 PM »

Since 180 volt dc permanant magnet motors with a 1750 rpm rating are readily available, could these be used as a generator for a wind turbine? If so what hp motor would be a good choice? Any thoughts would be appriciated!

Jerry · « **Reply #1 on:** February 02, 2006, 05:36:06 PM »

I use a 130 volt, 3050 rpm, 2.5 hp tred mill motor with 4 ft blade.

It does 400 watts top end.

JK TAS Jerry

vawtman · « **Reply #2 on:** February 02, 2006, 05:50:48 PM »

Fordman,3ph motors are even more plentifull and will easily outperform them.No brushes to wear either.

zubbly · « **Reply #3 on:** February 02, 2006, 06:14:17 PM »

hello fordman!

i did fly a leeson 1.5hp, 1750 rpm, 180volt dc permanent magnet industrial line of dc motor for a while with a 9 foot 2 blade prop. very often i got 30-35 amp into a 12 volt bank.

if the commutator and brushes are in good shape to start with, you can expect a long time service from it before brushes or commutator work is needed. i would however suggest a totally enclosed style unit though.

if you can get it cheap, go for it!

zubbly

vawtman · « **Reply #4 on:** February 02, 2006, 06:50:03 PM »

Zubbly how long did you have it flying for?Part of my job is to repair treadmill motors.I cant imagine the brushes lasting more than a few months at most.Also dust from the brushes builds in the holders on some models not good without error codes to lock the machine out.

Norm · « **Reply #5 on:** February 02, 2006, 07:34:45 PM »

But if a dc motor's brushes were designed for

higher voltages and higher speeds wouldn't the

brushes last longer at lower current and speeds?

( :>) Norm

nothing to lose · « **Reply #6 on:** February 02, 2006, 08:52:10 PM »

I have a dayton 2hp or better 180V dc, have not actually flown it though but in testing it looks very promising. Nice power at low rpms and better at higher rpms.

Mine weighs in around 75lbs and I been thinking of using it as a motor, can you beleave that, what an odd use for such a device

I am flying a small treadmill type motor of high DC volts, don't know it's HP off hand. It's got bad blades, in a turbulent area, does not seek the wind very well, and it still makes some power though not allot. Just something I tossed together with condiut, plumbers strapping, and old airconditinare fan blade, tail is a wooden wire spool end with L brakets and wood screws. I had an empty space and just wanted something spinning there till I get another project done.

I was really surprised when it cranked up a 12V 6" fan as a test load in some decent wind. I only thought of this one as a yard ornament really untill I heard that fan buzz at a high speed. Now it sometimes charges small SLA batteries when I need them.

Decent blades in a decent location I think it would make decent power.

How long the brushes would last in these motors I don't know. The big dayton has really nice bearings. I am geussing the tread mill type motor has cheap bushings though. That makes a bg difference also how long they may work.

nothing to lose · « **Reply #7 on:** February 02, 2006, 09:57:06 PM »

I don't know if it would work that way or not?

First look how we need larger wire for 12V compared to 48V for the same distance. Or heavy switches for 12V compared to 48V.

So if we were taking 12V or 48V from a 180v brush??? Less watts but is it less wear?

I don't know how a brush really rides a comunicator. Is it like a car tire where at high speed you slide over the rough spots, but at lower speeds you feel every bump? So kinda like, High speed the brush jumps the gap and not much wear, but maybe lower speeds the brush feels the edges and gets chewed down more?

I just figure if I find them at the scrap yard for almost nothing. Use them for something

Now it ticks me off I was lazy the other day. I was driving down the road and saw a realy nice looking treadmill standing on end next to the garbage cans! Looked like a heavy duty metal frame and I bet it had a great motor too. But I was in my car and no tools. Was too lazy and short on time to worry about going back to get it so I drove on by. Now I wish I had stopped and asked to get it later with my truck. 8 of 10 times people will tell me to move something away from the cans and get it later with the truck if I need too. I could use the metal from that frame now, motor was probably good, and controls most likely worked. I geuss I had the same problem as most people who throw out treads mills, just too lazy! They were probably too lazy to use it, I was too lazy to go back and get it

ghurd · « **Reply #8 on:** February 02, 2006, 10:18:06 PM »

Someone here (jump in if you know something) said low amps and volts could cause more sparking and shorter brush life?

For a factory unit, I'm sold on the 3 phase PM motors. Like an Efka, or a GE ECM. Never flown anything long enough to wear out brushes if they had them or not.

G-

Norm · « **Reply #9 on:** February 03, 2006, 06:15:49 AM »

They had an electric truck that really fried

everything trying to get it back to the charger

when it would barely move, but then that's

different circumstances isn't it?

And another thing you could probably use

lighter brush springs for a lower output generator...but Zubbly could tell

you all about brushes....

( :>) Norm.

zubbly · « **Reply #10 on:** February 03, 2006, 06:21:01 AM »

hello vawtman!

i flew the dc motor for approx 5 months. what had happened was the 2 blade prop totally ripped apart the motors base from the passing of the mast pole (creating that rocking motion) and eventually the blade hit the tower and totally blew up in peices. the motor it self though was fine and i just welded on another base on it.

inspection of the brushes and commutator showed no noticable wear. i had rewound this armature with original data, so there was nothing changed.

permanent magnet dc motors operate over a wide range of voltage and amperage as they are intended just for that. the most important thing to keep in mind is that the commutator and brushes must be in good shape to start with. replacing the brushes without properly refinishing the commutator will only lead to premature wear. there is no reason why you should not get many years of service from the brushes if all is in proper shape to start with.

zubbly

asheets · « **Reply #11 on:** February 03, 2006, 09:46:50 AM »

12VDC at 116 RPM? Sounds good to me...

Drives · « **Reply #12 on:** February 03, 2006, 11:40:06 AM »

I agree with Zubbly.

Please also look at this link.

http://www.fieldlines.com/story/2005/10/10/32025/266

I want to modify some of my comments from the above link....I work with very large industrial drives, and motors. I suspect my comment about being to lightly loaded, and premature failure, as it pertains to small DC PM motors may not be entirely correct. This does apply to the large motors, but the brush material may be different on the small (5HP and below) motors.

The link to the Reliance white paper is a very good read about communtator film.

I currently, am flying a 1/3hp 180Vdc DC PM motor, and it works great. I just need more wind!

vawtman · « **Reply #13 on:** February 03, 2006, 03:18:41 PM »

Zubbly,Your right about making sure the com and brushes are in perfect shape.Nice dark ring and new properly seated brushes before you put it 60ft in the air.Do you think using them as alternators would help the brushes last longer?Commercial treadmill motors have strong bearings and are tough as long as one doesnt neglect them.The brushes only last about 6 mnths or 5000miles.Also you probably need one that is totally enclosed.Sorry about your blades,Good news,I just completed my 5hp conversion.Ill post results.Couldnt have done it without ya.Thanks a lot.

Ungrounded Lightning Rod · « **Reply #14 on:** February 03, 2006, 06:56:20 PM »

Yes: That's HIGH amps, because of the low speed and low back-EMF. Lots of heating.

Ungrounded Lightning Rod · « **Reply #15 on:** February 03, 2006, 07:17:48 PM »

The brush life, assuming good commutator surface and no massive overcurrents, should be essentially proportional to the number of rotations of the shaft regardless of RPM.

RPM is proportional to back-EMF voltage - but the resistive voltage drop works a different way for motor and generator service, and your blocking diode and wiring add some more.

Pulling numbers out of nowhere let's assume about 170V back-EMF for 180V motor service and 17 volts for 12V battery charging. So your brushes should last in the ballpark of 10 times as long in a windmill as doing full-speed motor service.

But the windmill is spinning almost 24/7, so it sees 8766 hours of operation per year. (Call it 8,500 to take into account dead-calm times.) So for every 850 hours of operation you'd get between brush changes, running it as a motor at the rated RPM, you'd get about a year of service as a mill.

Norm · « **Reply #16 on:** February 04, 2006, 07:10:26 AM »

About refinishing the brushes..is there a certain way of cleaning between the segments

or chamfering the edges? I may have been doing

it wrong on all the little motors that I worked

with ?

Awhile back you knocked out my logic of thinking

that a nice bright shiny copper commutator was

the ideal.

I must have went thru dozens of used heater blower motors for the Astrovan trying to get one that would last, rather than spend $80 for a

new one.

The 'ol Astrovan is history now...but still

would be nice to increase my knowledge of those

little blower motors.

Thanks Zubbly

( :>) Norm

Drives · « **Reply #17 on:** February 04, 2006, 07:44:22 AM »

This is what I use after changing a customers brushes, and light cleaning of the commutator.

http://www.idealindustries.com/cm/BrushSeater.nsf

I have seen it where a large build-up of grease/gunk has built up between the communtator segments. If you do not want to remove the armature for cleaning, then use a "O-ring" pick, or some other type of dental pick, to gently scrap the gunk out. I always vacuum first to remove any loose debris. DO NOT use a flammable solvent to clean a communtator. I have seen a couple "rookies" spray flammable solvent on a communtator that was running....nice fireball!

Here is another nice pic of communtator diagnosis.

http://www.remco1.com/tech-tips.htm

Hope this helps.

coldspot · « **Reply #18 on:** February 04, 2006, 09:55:46 AM »

DC Motor commutator-

I am not a PRO like say zubbly but

Over the years I have played with a few DC motor, MUCH smaller.

In the old days when we would race our slot cars and later when RC OFF-ROAD

was my thing, I would use a simple pencil earasor to clean up the commutator.

Granted all we wanted was MORE power OUT and life was short, from over voltage.

But when a race heat was starting, if I didn't have a shinny new looking commutator.

My car didn't pack the front wheels as far as when it did with a freshen'd up commutator. ( had a cop once radar, (him laying on the ground, lol), my 10th scale off-road car with foam road wheels @ 38 MPH in 8' !!!!!)

just my $0.02

vawtman · « **Reply #19 on:** February 04, 2006, 03:03:39 PM »

What size/type turbine are you planning on Fordman?

fordman · « **Reply #20 on:** February 05, 2006, 08:39:05 AM »

I am planning on using a 6' blade with a 1 hp motor/generator. My average wind speed is about 10-12 mph.

Slingshot · « **Reply #21 on:** February 06, 2006, 04:45:41 PM »

If you mean zero to 38 MPH in 8', something must have been wrong with the measurement. That's six G's.

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Author Topic: 180v dc motor (Read 4645 times)