Electric Mower Motors any Good

[trikeman]

Anyone know if this might make a decent motor for an electric vehicle?

http://atlanta.craigslist.org/grd/725035864.html

[AtomicZombie]

If by some fluke the motor actually has a real housing, it will be very difficult to adapt to anything. The motor is probably molded right in to the plastic.

Brad

[trikeman]

Thanks papa. I might like to try a motorized bike, but I am not sure I am ready for the $500-$1500 motor yet.

[TheKid]

I saw a weedwhacker motor used on the MARS site a while ago.

[jaythedogg]

Use a car starter. A little rewiring is all it takes.

Here is a link to the DIY setup: http://www.diygokarts.com/engine/car-starter-motor-conversion.html

Hope this helps. :)

[trikeman]

Thanks jay. How long does a car starter work in that environment? I have always heard that you will burn your starter up, if you crank it longer than about 30 seconds at a time. I never had much desire to test that limit on my car ;)

The guy called me about the mower last night, but I missed the call. I am wondering if I should pick it up for $15? I am not even sure I can put a controller on it. Further investigation reveals it to be built by Black and Decker and it looks like it is 1400 Watts. It probably does noy have a controller other than off and on.

[jaythedogg]

Thanks jay. How long does a car starter work in that environment? I have always heard that you will burn your starter up, if you crank it longer than about 30 seconds at a time. I never had much desire to test that limit on my car ;)

The guy called me about the mower last night, but I missed the call. I am wondering if I should pick it up for $15? I am not even sure I can put a controller on it. Further investigation reveals it to be built by Black and Decker and it looks like it is 1400 Watts. It probably does noy have a controller other than off and on.

Controllers for throttle on an electric motor is nothing more than a heavy duty Rheostat, which is a volume control, or dimmer switch, in essence.

You can buy heavy duty rheostats online & from alot of electrical supply companies. A simple dimmer switch or volume control would not work, as the amperage rating is too low to handle a car battery.

Your rheostat would be your throttle inline between your power source & your motor. Controlling the rheostat could be done by a cable to a throttle handle on the handle bars, or a pedal.

I assume the starter motor would work well, as they recommend it for the DIY electric go kart. I assume this because a starter is meant to push a MUCH heavier load, ie a car engine, which involves compression & whatnot. A 200lb person shouldn't be a huge drag on it. If you are worried about the drag on it, & want better lifetime/performance, put a power band inline between the motor & the drive axle.

Info on power bands can be found:
(AKA Torque Converter)
http://www.bmikarts.com/1-sprockets-ch...hes-torque-converters.shtml (http://www.bmikarts.com/1-sprockets-chain-clutches-torque-converters.shtml)

A Torque Converter is essentially a limitless (limited) gear transmission for small vehicles (in this case). It provides low or high torque based on the load. Good for climbing hills, or gaining speed. It is completely self operating, & helps keep heavy load off of your drive motor.

Can be a bit pricey though, generally between $140-$200, but well worth it! (I have heard, with some experience in machining, you can machine your own)

Hope this helps.

Edit: Starters are a viable option, as they are readily available for a low price, from a junk yard. You can also refurbish them yourself, if you feel ambitious enough to learn. :)

[AtomicZombie]

The real problem with the starters is that they were designed for very short duty cycles. Because of this, there are no real bearings (just crappy bushings), the motor has almost zero cooling, the brushes are small. Add to this to the fact that the shaft is difficult to adapt, the unit is non reversible and the efficiency is rotten.

I would put car starters last on my usabilty list. An alternator is actually easier to convert and much better in the end.

If you really plan to try the starter option, find a Mazda or Toyoto starter, they have a 5:1 or better gearbox on them, so at least you can run them at a decent RPM range.

Brad

[trikeman]

I definitely woudl not want to use a rheostat, since it would consume so much power. The idea of converting a car alternator sounds interesting, but it sounds a bit complicated here

http://www.fossilfreedom.com/alternator-conversion.html

I guess that is why people pay so much for those ready-to-go hub motors.

[jaythedogg]

This is why I am here. :P

I have lots to learn, as I am a bit old school. :)

[trikeman]

As I said in another post to papa, I got the mower for $10. I took the top off and think I found the problem - Canukian electronics!!!! (See the maple leaf on the circuit boards?)

Only kidding lol.

Anyway, the guy told me it had no battery in it at all - obviously it does have two 18AH 12 volt GEL cells in series, a crude controller an a charging and stopping circuit.

I tried spining up the motor with 12 volts from my car battery charger with a 55 Amp starting circuit, but it didn't budge. I am assuming the batteries are shot from sitting around uncharged. I wonder if I can rejuvenate them at all. The motor is pretty cheesy looking - looks like an armature in a tin can.

http://www.atlantamusclecars.com/DeltaWolf/Mower1.jpg


http://www.atlantamusclecars.com/DeltaWolf/Mower3.jpg

http://www.atlantamusclecars.com/DeltaWolf/Mower4.jpg

http://www.atlantamusclecars.com/DeltaWolf/Mower6.jpg

[trikeman]

Some success with the motor. After disconnecting it from the other circuits (mostly) got it to spin up on 12 volts with my car battery charger. Its pulling about 7 Amps. No idea what rpm its turning at (maybe 1500 rpm). Movie is about 4 Megs.

http://www.atlantamusclecars.com/DeltaWolf/MowerMovie.avi

[SirJoey]

Hey guys, speaking of rheostats, do those AC dimmers for home ceiling lights actually save power, or do they just dim the light & still use the same amount?

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[AtomicZombie]

They save power, but have nothing to do with rheostats...

** Geek Text Alert! ***

A light dimmer works by essentially chopping parts out of the AC voltage. This allows only parts of the waveform to pass to the lamp. The brightness of the lamp is determined by the power transferred to it, so the more the waveform is chopped, the more it dims.

Mains power is comprised of an alternating current that flows in one direction and then in the other, along the cable, at the rate of 50 or 60 cycles per second (known as Hertz). The value 50 or 60Hz is dependent on the countries power system. The current alternates back and forth changing direction at the zero point. If we were to look at this waveform it would appear as a stretched S shape on its side ~. Draw a line through the middle and this is what is called the zero crossing point. At this instant in time no current is flowing in either direction. This is the point at which a dimmer is electronically synchronized to turn the power ON or OFF. By chopping the waveform at the zero-crossing point, smooth dimming can be achieved without the lamp flickering. This turning on and off of the power device occurs every time the mains crossing point is reached (half phase), 100 or 120 times per second.

*** End Geek Text ***

A rheostat large enough to handle a few hundred watts of lights might run as hot as a toaster and take up the same amount of space.

Brad

[SirJoey]

Ok, thanx. I thought those variable dimmers WERE rheostats. Shows what I know... :rolleyes:

Hey, at least I can install one!

BTW, would one of those work okay with my ceiling fan?

http://img384.imageshack.us/img384/7131/sirjoeysigmedij1.gif

[AtomicZombie]

The general rule is no, they will not due to the motor having an inductive load. I have used them and they make so much noise that it is not worth it. You can actually get inductive load dimmers, but they are more expensive.

Brad

[trikeman]

Well... Here is the final booty from the mower (other than the very small 24V charger). Now, all I need is a couple of new 12V batteries a controller and I may strap it to a frame.

http://www.atlantamusclecars.com/DeltaWolf/Motor 003.jpg (http://www.atlantamusclecars.com/DeltaWolf/Motor%20003.jpg)

http://www.atlantamusclecars.com/DeltaWolf/Motor 004.jpg (http://www.atlantamusclecars.com/DeltaWolf/Motor%20004.jpg)

These are supposedly exact duplicates (2 of them linked in series) of what was originally in the mower.

http://www.batteryspec.com/cgi-bin/cart.cgi?action=link&product=67&sub2=671115

[AtomicZombie]

Looks like it will work - even has mounting bolts.

I wonder of it is the same as the Bosch750?....

http://howto.killerhurtz.co.uk/bosch_internals.jpg

Should be able to get up to city traffic speeds with a good controller.

Brad

[trikeman]

Looks like I may have jumped the gun on my assumption that the batteries were complete toast. I could not get my charger to push more than a few amps into them, before it said they were fully chaged, so I just assumed they were probably bad. I only have a 12v charger, and since the guy that sold me the mower couldn't find the transformer that plugs in to charge the mower, I put each of the 12v sides on my charger for a bit.

I am guessing that the tiny transformer that comes with the mower and plugs in to charge it must be more than 24V AC to drive the full wave rectifier enough to have something left to charge a 24v battery pack. Maybe I will see if I can find one. Since there is a full-wave rectifier on the charger board, I am also assuming that the "charger" that Black and Decker sells for it is really just a transformer and a tiny one at that.

Hey maybe I should cut my yard with it at least once.

When I connected the motor leads across the battery, I got this:

http://www.atlantamusclecars.com/DeltaWolf/Motor 005.avi (http://www.atlantamusclecars.com/DeltaWolf/Motor%20005.avi)

Noisy little sucker without any sort of cover over the brush end.

By the way Brad, I don't think its a Bosch 750, since it only has two brushes the Bosch has 4. 5/8" shaft with two flats machined on it, and a screw thread. I will look for a sprocket.


Hmmmm. Where did I put the new AZ book with the electric scooter plans?

[jaythedogg]

Looks like I may have jumped the gun on my assumption that the batteries were complete toast. I could not get my charger to push more than a few amps into them, before it said they were fully chaged, so I just assumed they were probably bad. I only have a 12v charger, and since the guy that sold me the mower couldn't find the transformer that plugs in to charge the mower, I put each of the 12v sides on my charger for a bit.

I am guessing that the tiny transformer that comes with the mower and plugs in to charge it must be more than 24V AC to drive the full wave rectifier enough to have something left to charge a 24v battery pack. Maybe I will see if I can find one. Since there is a full-wave rectifier on the charger board, I am also assuming that the "charger" that Black and Decker sells for it is really just a transformer and a tiny one at that.

Hey maybe I should cut my yard with it at least once.

When I connected the motor leads across the battery, I got this:

http://www.atlantamusclecars.com/DeltaWolf/Motor 005.avi (http://www.atlantamusclecars.com/DeltaWolf/Motor%20005.avi)

Noisy little sucker without any sort of cover over the brush end.

By the way Brad, I don't think its a Bosch 750, since it only has two brushes the Bosch has 4. 5/8" shaft with two flats machined on it, and a screw thread. I will look for a sprocket.


Hmmmm. Where did I put the new AZ book with the electric scooter plans?

Cool. :)

BTW I love Daisy Sour Cream. :P

[jaythedogg]

So... Updates available yet?