automobile starter motors

[Plats]

IS THIS AN APPROPRIATE QUESTION FOR THIS FORUM? Do you have information, experience, or suggestions regarding using starter motors from trucks and cars under continuous operating conditions? My hopes are to use a low cost motor to power my boat. My question is how much can I load a motor without it overheating. How much additional HP can I expect by having the case wrapped with copper tubing and circulate cold water to keep the case cool? What is a good RPM to have them run for best efficiency? I plan on using PWM to keep in the wanted power and speed curves. If I build my own controller, what is the best method to use for speed and power control? Should the field be kept alive constantly and pulse the armature, operate in pulse mode with a series wound motor, or ????? If you don’t have information and or thoughts along this line, any idea where I can go on the net and find people who might have interest in this method of using motors? Thanks for any and all ideas, suggestions, or just comments, Bernie

 

[kuwait]

Hi Plats,
I don't think you can have a normal vehicular starter for power boat application.In cranking application(prime mover of engine) it is in circuit for only a fraction of time and by that time it drains from the battery current in 100s of amps.You need to have very high ampere hour battery which will come very heavy and will drain rapidly - low mileage .Further I think these starter motors are not rated for continous duty.Go for outboard engine instead.

 

[dpc]

I agree with kuwait, a starter motor is designed for a very short duty cycle and would probably not last very long under continuous operation due to overheating.

Even it could operate continuously, I suspect it would be incredibly inefficient and consume lots of power. Plus you would have to provide some type of speed control.

I think the least expensive solution would be to buy an inexpensive electric trolling motor designed for this application.

 

[buzzp]

I agree with the above posters. The starter will only last a short time, like minutes. For every 30 seconds of starting it needs to cool for 2 minutes. Try the suggestions above or look at continuos duty DC motors.

 

[Plats]

Yes I realize it cannot be run continuous at full power, thus the concern about PWM. I have seen them used in commercial applications and last for years and they are a very solid motor thus used. They are built for max. load, and when used under less demanding loads, the bearings and brushes last a long time. I have lost my contact with these folks, and do not know how they were controlled, operated, etc. For my use it will not be turning a prop. A tolling motor will not work. Thanks for all inputs and ideas. They all are very interesting and help me to think about what I am doing.

 

[uppili11]

I HAVE COME ACROSS AN INTERESTING MOTOR.HAVE YOU SEEN A HAND HELD VACUUM CLEANER (I THINK BY ROYAL APPLIANCE).A PRETTY SMALL MOTOR
(46MM STATOR CORE)BUT IMAGINE THE RATING IS 1.0HP!!!!(720WATTS)
YOU CAN OPERATE IT CONTINUOUSLY BECAUSE THE INHERENT NATURE OF THE
VACUUM CLEANER IS TO SUCK AIR WHICH IN TURN COOLS THE MOTOR EFFECTIVELY
THE LIFE GUARANTEED IS 250HRS AND THE VAC CLEANER ITSELF COSTS
20 DOLLARS!!!.TRY TO USE PWM FOR THIS TYPE OF MOTORS WITH APPROPRIATE COOLING

 

[Plats]

Thanks for the info, however my guess is that it is 110 volt, 60 Hz. What I am looking for needs to be DC (Batery) and about 24 volt. I need speed control.

 

[jbartos]

Suggestion: Motors for marine applications are typically built lighter than ordinary motors and they belong to a category "marine applications." Nowadays, permanent magnet motors are becoming more attractive for marine applications. E.g. future Navy ships will have permanent magnet propulsion motors. Please, what is exactly that motor going to be used for if not for propeller?

 

[Plats]

Working on a 20 foot sternwheeler. The motor will be driving the paddle wheel. Thats the reason I need varible speed, and reverse. From a distance she will appear to be an old time sternwheeler. Thinking about putting one on each side. When running would like to have a little over one horse. Of course running slow will need less, thus the need to have PWM.

 

[jbartos]

Suggestion: This application has a hidden hitch, namely, the motors will have to have synchronized speed, else, the rudder would often have to be used to correct the incorrect navigation, which means that the ship sail efficiency is considered in here.

 

[Plats]

The wheel is one system. It is a sternwheeler, not a sidewheeler where there are two wheels. The paddle wheel is not separated into two sections.

 

[GalJanos]

I was wondering similar problem. I planed to build an EV with starter motor. I checked the problem quite deeply. There are some problems while use starter: one is, the bearings. You have to change the bearings to roller type. It needs modified shields. The other is that the starters are designed to give very high torque at low speed. The efficiency is appr. 50-60%. It is applicable, but should be rewound. Without any calculation I would suggest 2 times more number of turnes in both stator pole and rotor armature. And I would change the brushes also to natural graphite. In your application the current will be much lower, so the high current density type brushes like metal-graphite will not be proper.

 

[peebee]

I agree with all above posts. The starter is designed and optimized for a very different application than what you're looking at. Why not look at other 12-24v motors that are designed for continuous usage? There's got to be lots of better suited off-the-shelf motors available for RV, automotive, and marine applications. A troller motor still sounds like a good idea to me -- how come you don't like it? Other motors might include water pumps, winches, hydraulic pumps, tools, hybrid-car wheel motors, blower/fan motors, etc.

 

[SteveHuck]

Just a thought. Try looking for a used golf cart. You can get a smashed up one for as cheap as $100us. The motor is there and the speed control would also be included. Heck, you may even get the charger for the batterys!

 

[jbartos]

Suggestion: Visit

http://www.thomasregister.com

and type Motors: DC under Product or Service which will return 322 companies to inquire about the right solution.

 

[peebee]

I like the golf cart idea.

 

[Plats]

SteveHuck and all: Steve I like your idea of using a golf cart motor. I have been looking for one for several months, and just haven’t been able to come up with what I want yet. That was my original idea. Then I started looking at alternative possibilities. Starter motors, I can get all I want for a song. Price!!!!, that is what got me looking at the them. Controls don’t bother me, that I can take care of. A couple days ago I located a motor out of a powered pallet jack. Price is right. Will check it out. Still looking for golf cart equipment as I think they will come as close to what I want as I can get, at a reasonable price. Thanks to all that had comments, and with a little bit of luck this project will be on the water this summer.

 

[jbartos]

Suggestion: It may be worthwhile to check the motor prices at various electrical distributors and manufacturers. There may be some inexpensive motors available too.

 

[Plats]

I have done some checking, not much, but the prices I have come up with so far are higher than I want to go. Who knows, that may be where I end up, but at this point I am still looking for a bargin. After all, this started out to be just a whim, and a hobby.

 

[Thorn3]

hi,
I am presently building my kids an electric go-cart. It is a new and unusual design. In my search for an appropriate motor to drive it, as well as batteries, chargers and controllers, I have found this site to be the only one on the net that offers all of what I need. Please visit:

http://ecoleco.freeservers.com/scooterparts.htm#MOTOR200

They have 24VDC motors there, at a very reasonable price, with controllers, batteries etc. I have seen an 800Watt motor available there, at 24VDC. These motors are specificaly designed to move people around, up and down hills, for extended periods of time. Maybe this will help you?