# lawn mower motor?



## thedarlington (Aug 17, 2008)

hey guys what do u all think of a lawnmower motor for an ebike? i dont really know what type of motor they usually tend to carry and how easy a battery conversion would b from ac cord power


----------



## zig06 (Aug 3, 2008)

It might be just a waste of time, unless your willing to find (and pay for) a DC to AC controller.

Lately it seems like the cheapest and most direct route is getting a controller from an old golf cart, and a Hi-Lo series wound DC motor, that's been reworked to have the correct output shaft for your application.


----------



## skullbearer (Jul 9, 2008)

Not to mention all push sized electric mowers run on extremely low power motors. Even a riding mower doesn't need very much power, and I've seen some modern ICE riding mowers that only have maybe 15% more HP than an ancient ICE push job we traded in to SMUD for an electric a year back. That old mower was loud, a gas hog, but man when it hit a rock that thing would embed itself in the fence, whoo wee! Once it embedded itself in my leather boots, so we got rid of it.


----------



## Amberwolf (May 29, 2009)

Old topic, I know, but for anyone new looking at threads like this for answers:

There are lawnmowers using PMDC motors. My used Black & Decker (1HP?) green-and-black one did, and simply had a bridge rectifier between the wall-outlet's power cord and the motor. The motor itself might or might not have had much torque; I never had a chance to find out, as while I was mowing the lawn with it (long before I decided to build an e-bike), one of the magnets inside came loose from the casing due to vibration and rust, and shattered on the spinning armature, then pieces of it sheared thru most of the top-end armature windings. 

I have no idea what the mower went thru before I got it, but I'd guess not a lot of good things. 

But I think that motor, with suitable reduction gearing, would have made a decent ebike assist motor.
________
Colorado Medical Marijuana Dispensary


----------



## Dennis (Feb 25, 2008)

> It might be just a waste of time, unless your willing to find (and pay for) a DC to AC controller.


Wrong! The motors used in electric mowers, vacuum cleaners, corded power tools, and blenders is a universal motor which is nothing more than a series wound DC motor with thin steel laminations to reduce eddy currents since they are being powered by AC. Now it may seem a paradox for a DC motor to be able to run on AC, but it is true for field wound motors able to work on either because series and shunt wound motors cannot be reversed unless you change the armature polarity OR the series field polarity or shunt field polarity for shunt wound motors, *but NOT both*, else the motor's rotation will be the same.

If you have studied AC then you should know that AC reverses polarity every half cycle and thus it is like someone reversing the battery leads on the battery terminals with the other end of the leads connected to a series wound motor resulting in no change in motor direction because they reversed both field and armature together. Only PMDC will not work on AC because the fields are permanent magnets that have a fixed magnetic polarity.


----------



## Amberwolf (May 29, 2009)

What you post above is true, except you should probably add "Most of" to the sentence starting after "Wrong!". Most definitely not all of the motors in all of those devices are always universal motors; certainly my B&D lawnmower was a PMDC motor.
________
Web Shows


----------

