# another "teach me" motor question



## dmac257 (Jun 30, 2010)

I am looking at different motors for some small conversions of a lawnmower, bicycle, and maybe a go kart, and I realize that I have some confusion about the different types of motors.

Brushed DC motors
Brushless DC motors
PM motors
Sep Ex motors
Series wound motors


Are there other types of DC motors used in EV?

most common seems to be series wound brushed DC motor with PWM controller?

Can the same controller be used for different types of motors? I was watching a couple of auctions for motors and low voltage controllers but I need to get straight in my head before actually buying anything.

Also, there are a couple of motors termed gear head motors with motor turning way faster than the drive sprocket. Are these any good or should I just use normal motor and drive it with a controller without the gear box?

I am sure I will have more questions,
Don


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## Guest (Jul 30, 2010)

Thats pretty much it but there are variations on each kind. The most common type is the Series DC motor with brushes and uses a PWM controller. For Golf carts you have small AC drives and DC SepEx motors. For low cost and ease of use I'd go with the SepEx motor and SepEx controller for small projects. If you have a go cart you can use regen to stop and you can use that too on a small motorcycle. If you want to go freeway speeds I'd say a good AC or DC Series system with a proper controller. 

A DC SepEx controller will not work with a DC Series motor. You need a matching controller for each motor and you need one with the proper voltage range too and stick within that range. I am going to do a Cushman Truckster and it is already electric but old style. I am going to use a D&D SepEx motor and run 48 volts and use regen too. It will be street legal and should go pretty darn good. I may even go with 72 volts as the controller will do that. It will be easy and it will be fun. I can easily put 12 6 volt batteries in this thing. It will be a flat bed with removable sides when done. 

SepEx for large fast vehicles is pretty much a dead horse. Voltage too low and not enough controllers on the market to make it a true viable source. 

Pete


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## juddmeyers (Jul 14, 2010)

I thought I was confused, but now I'm not sure. I have been thinking about trying some smaller projects like bikes and god forbid my lawnmower, but I thought the benefit of trying smaller projects was I could make lead acid work as the battery pack. My understanding is that Regen is damaging to batteries that can not accept a rapid charge (such as lead acid). Is this true, or are we talking about a high tech battery lawnmower? I live around people who could be swayed by a single deep cycle battery powering a lawnmower, you're never seen working on, but all I have is golf cart motors. A little over the top for a push mower. Has anyone made any awesome push mowers with 1 or 2 6 or 12 volt deep cycles?


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## Guest (Jul 30, 2010)

A golf cart motor and controller will work fine for a lawnmower. You will need to make a bracket to hold your batteries and it will be a bit on the heavier side if you use large golf cart batteries. They do make small format AGM batteries that would work just fine. I'd say you could get away with a couple Optima batteries and do great with a push mower. If you can get one with the larger diameter wheels it will be much better. The motor I take out of the Cushman will more than likely be used in our push mower. I will use two 12 volt optima batteries and that should do just fine for the front or back yard per charge. It will keep it lighter too. A simple switch will do as well. I don't plan on enough voltage for over speeding the series motor which is in the Cushman right now. It is a 24 volt setup. Should be easy to mount two optima's on the frame and just plug into our 24 volt charger. I may use a cheap curtis 24 volt controller. 

It is perfect to do a small project then do a larger one. I decided to go for broke and build a car first then go for the smaller projects. It worked. 

Pete


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## dmac257 (Jun 30, 2010)

gottdi said:


> A golf cart motor and controller will work fine for a lawnmower.
> [SNIP]
> 
> The motor I take out of the Cushman will more than likely be used in our push mower. I will use two 12 volt optima batteries and that should do just fine for the front or back yard per charge. It will keep it lighter too. A simple switch will do as well. I don't plan on enough voltage for over speeding the series motor which is in the Cushman right now. It is a 24 volt setup. Should be easy to mount two optima's on the frame and just plug into our 24 volt charger. I may use a cheap curtis 24 volt controller.
> ...


Is a controller really necessary for a push mower? Would it make a difference in how long the battery will last?

Also, from what I could find, most lawn mower motors turn at 3600rpm and I am having trouble finding a motor that turns that fast at either 12v or 24v. Anyone have a source for 12v motor that will shread grass? Or would be better to have 1:2 pully setup to double the blade speed under the deck. Lots of 1750rpm motors and that would get close to design speed for the mulching blade. How would this effect the battery? I need to get one hour out of a charge. 24v would make it pretty heavy to push around... hmm maybe self propelled (now would that be a separate motor for the drive wheels?) 

Don


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## Guest (Jul 30, 2010)

Yes a controller is required but if you need an hour you need a riding mower with more batteries. Many motors will do 3000 rpm. The electric motor has more torque than a gasser so will just eat through the lawn. It can do so at lower speeds but still fast enough to cut good. Most folks don't have that size yard that would require an hours run time to get the job done. I'd do one yard one day then the other the next. No need to do it all at once either. Search out riding mowers on EVDL. You will be well ahead to do so. 

Pete


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## Duncan (Dec 8, 2008)

Hi Dmac

You can buy a battery lawn mower - we have one it works well!

If I was going to build one on the cheap I would look at radiator fan motors,

If I go back to your original question about motor type
- on DC motors if it has brushes it *can be run* without a controller

If it does not have brushes it needs a controller!

Saying that it will run but the "control" will be the amount of voltage you give it - too many volts and it could over-speed or melt

Brushed motors from AC machines can also be used on DC

If you are just messing about get some motors - fans, vacuum cleaners, radiator fans
Hook some batteries together and play

A lawn mower may work with an old radiator fan motor - might take two!


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## Guest (Jul 30, 2010)

> ...........too many volts and it could over-speed....


Hence the need for a controller even with a brushed DC. You have a throttle on a gas engine don't you? Well, you should use one on your motor as well. I'd use a bit larger motor than a radiator motor due to the fact you have a large heavy blade spinning around and cutting grass vs a fan pushing air. Use an old golf cart motor with controller.


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## dmac257 (Jun 30, 2010)

gottdi said:


> Hence the need for a controller even with a brushed DC. You have a throttle on a gas engine don't you? Well, you should use one on your motor as well. I'd use a bit larger motor than a radiator motor due to the fact you have a large heavy blade spinning around and cutting grass vs a fan pushing air. Use an old golf cart motor with controller.


I am inclined to go with the golf cart motor and controller as that is what I am attempting to learn about on small scale before I do full auto conversion .. but that would be for a go kart.

All the lawnmower conversion project sites i looked at do not mention any type of controller.. but they are matching a 12v motor to one 12v source or 24v motor to 24v source ie:
http://visforvoltage.org/topics/gas-conversion-lawnmower 

what are the advantages to having a controller?

The motor i am considering is Leeson 108052 - 3/4hp 1800rpm 24v 29a

and would something like :

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250656622904&ssPageName=STRK:MEWAX:IT 

work or do you recommend something else for the controller?
Don


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## Guest (Jul 30, 2010)

The advantage is speed/power control. If you need to accelerate (kart) or hit a think patch of grass (mower) you can increase the power/speed of the blade to chew through the grass or if your in a kart, to pass someone. One speed one power level is not too efficient and leaves no room for extra if needed. You should go with a controller that can dish out some amps. You don't have to use it all but having that extra is a good thing. I'd say no on that controller. Use one from a golf cart. The golf cart will provide all the parts required to convert your kart or mower.


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