Car Starter Motor

[Doc Sprocket]

I believe that a light vehicle (I think I already mentioned this) geared decently will be a far lesser load than the engine was with all it's compression and resistance. By all means do it, and let us know how the heat thing works out- I don't think it'll be that bad.

 

[gokartmozart]

Well, I measured my flywheel and it is 12 inches across (too many teeth to count) and my starter measures about an inch (the gear). So this is about a 1:12 gear ratio. I remeber reading about the amount of torque needed to turn over an engine but for now it eludes me. I think if I have a 5 inch wheel, solid axle, and a 1:2 gear reduction my little starter will work. I will do the math.

Also, I dont thing I will have to remove the gear, but can weld the gear I have right to the starter gear. (Of course I will have to watch the heat so it does not destroy the motor windings.)

 

[Doc Sprocket]

If you can get it halfway true, you're golden. Although I'm still not sure about the ratio. If 12:1 with the compression makes the starter sweat, perhaps 2:1 on your project may be too much. But let's face it, it's all academic at this point. I think you should put the gear you have (10T?) or whatever on it, build the vehicle, test it out, and adjust ratios as necessary. Don't think we'll ever find a published RPM spec on a starter- it's not normally important.

 

[GreyhoundOfYerfDogs]

Here are some specs I found on the net.
Bosch motor
Engine cranking speed is approx 120 rpm,
no load test its 7100 rpm @ 55 amps 12volts for a 186, and for a 202 its 12volts @ 65 amps,
Lucas motor
8500 rpm at 60 amps and 12volts

 

[honda-gx-power]

Take a crap drill apart and instead of using that button that someone is showing you few post up, Use the trigger out of the drill as a gas throttle for your starter motor and you might be able to limit what power your sending to the starter motor with the drill trigger.Hope you no what i mean.
Just an idea as im not expert

 

[sideways]

Take a crap drill apart and instead of using that button that someone is showing you few post up, Use the trigger out of the drill as a gas throttle for your starter motor and you might be able to limit what power your sending to the starter motor with the drill trigger.Hope you no what i mean.
Just an idea as im not expert

That little trigger wont take the amps the starter will pull, it'd just melt or explode in a shower of sparks. Not good!

Thanks

Hayden

 

[honda-gx-power]

Just an idea that bud^^, you lot will no more than me by far.
Have you seen them wind up radios and torches ect. well the thing that you wind up and it charges the batterys up in the wind up torches radio ect , can you not get big ones of them and fit it to kart wheel some how and have it charge the kart battery as your driving the kart.Have one on each wheel.
Same again just an idea

 

[KieranM]

I have heard that dynamos off older cars before alternators make great motors when there wired up on a kart. Although I dont know if they are easy to find where you live.

 

[sideways]

I have heard that dynamos off older cars before alternators make great motors when there wired up on a kart. Although I dont know if they are easy to find where you live.

Every dynamo I've hooked a battery up to (and that's a lot! A friend needed one for his VW buggy) had pretty much no power at all, stop it with your hand easily. This was from a fully charged 12V battery, even with 48V I don't think it'd push a kart.

Starters can (and have) be adapted to use on karts, your battery will last a few mins max though.

Thanks

Hayden

 

[KieranM]

Every dynamo I've hooked a battery up to (and that's a lot! A friend needed one for his VW buggy) had pretty much no power at all, stop it with your hand easily. This was from a fully charged 12V battery, even with 48V I don't think it'd push a kart.

Starters can (and have) be adapted to use on karts, your battery will last a few mins max though.

Thanks

Hayden

Yes your correct on that one, I looked over that I read it in a robotics forum.

Thanks

 

[honda-gx-power]

Message these guy and you well get info
http://www.youtube.com/watch?v=bERjkSTYOdU&feature=related

 

[gokartmozart]

Yeah, I was looking over the starter, and I forgot about the solenoid kicking out the gear. It just looks more complicated to use then worth.

It is sad there are so few options for electric motors. Even with a good golf cart motor, the batteries are a killer. You could easily spend $500 for something you can accomplish with a small IC engine. God, I have three little engines sitting on my shelf.

But, I just love the idea of a electric go kart.

 

[Doc Sprocket]

Ok. Bolt a generator to the kart. Plug in a kickarse inverter, and run a 120v, 3hp compressor motor. Call it a "hybrid".

Right. Got my laffs out. Don't lose heart. Have a look at the possibility of fixing the gear in place. This could involve removing the solenoid and running a remote relay, or defeating the little "shift fork", or something. Surely you can pull this off, and I'm aching to see it happen.

 

[gokartmozart]

Your funny, but I actually have a spare alternator sitting in my basement. I am still working on my other kart, but I will give a full hearted try after I am finished with it.

 

[anderkart]

Yeah, I was looking over the starter, and I forgot about the solenoid kicking out the gear. It just looks more complicated to use then worth.

You could cut the Bendix down, and then weld your small drive sprocket to its gear, slide that assembly back on the shafts splines and then shim (tack or weld) in place, Just dont overheat that Armature.

You could probably trim a little off that nose cone to get more clearance for the sprocket and chain, but dont get too wild.



I might have another plan to end up with an inch of your Armature shaft sticking out the end of your nose cone, so you can mount any size drive gear out there.


If you first removed the Solenoid, (#16 on the diagram) then unbolt the 2 long through bolts (#31 and 35) and slide the aluminum nose cone (#2) off.

Then remove the snap ring (#6) at the very end of the Armature shaft, you'll should then be able to remove the Bendix assembly (#8).

Ok, here's the real tricky part I'm not sure of... I'm thinking if an inch of the nose cone was accurately cut off, (the side that mates up to the motor) and reassembled, you'd end up with an inch of shaft sticking out the end of the nose cone for your gear.

Another thing you'd probably have to do is shim that end of the shaft so the Armature would only have a very small amount of end play.

Sounds wacky but it just might work, let me know if you need help.

 

[gokartmozart]

Cool...do you know the kinda power a starter can generate?

If I gear it one to two will it provide enough power to move 5 inch wheels with solid axle?

 

[devino246]

Cool...do you know the kinda power a starter can generate?

If I gear it one to two will it provide enough power to move 5 inch wheels with solid axle?

Enough power to move a car in third gear. I forgot to take my plymouth out of gear one day when starting, and because its old, it doesnt have a neutral safety switch. Made me jump.

 

[sideways]

Cool...do you know the kinda power a starter can generate?

If I gear it one to two will it provide enough power to move 5 inch wheels with solid axle?

Anywhere from about 800w to about 5hp.

5hp would be on a big industrial or truck diesel engine though.

Thanks

Hayden

 

[KieranM]

Enough power to move a car in third gear. I forgot to take my plymouth out of gear one day when starting, and because its old, it doesnt have a neutral safety switch. Made me jump.

Same happend to me in an old escort I used to have.

 

[anderkart]

If I gear it one to two will it provide enough power to move 5 inch wheels with solid axle?

I found a couple guys claiming that GM starters like yours free-spin between 1000 and 1500rpm.

So if that's true... A 1 to 1 ratio kinda seemed more appropriate to me. The speed calculator results for this with your 5" tires were:

15mph at 1000rpm.
OR
22mph at 1500rpm.

I think with a fairly light weight kart and driver, your starter motor should have enough power to hit somewhere near these speeds riding on a flat hard surface.