Found Bad*** Briggs and Stratton Electric motor in garage.

[jace]

so, i was digging around in my grandfathers garage, and came across a Briggs and Stratton "e-Tek" motor, i'd like to use it for an electric cart because from what i read, it's a MONSTER, i made the mistake of holding it and attaching it to a 12v battery and it ripped straight out of my hands(and i had a death grip on it)


Does anybody have an idea on what electronics i would pair with this motor? here's a link http://www.robotmarketplace.com/products/ETK-ETEK.html

also the link says this thing is capable of making 15hp?

 

[anderkart]

Wow cool motor

Your link says that motor can have up to a 330 amp draw. If you found any speed control components rated that high they'd probably be super exspencive.

That motor can draw as much amperage as a cars starter. If you want an easy/low cost option, you could simply instal a foot-start switch (like old 1940's cars and trucks used) as your gas pedal.

Heres one you could order online for $13: http://www.partdeal.com/switches/specialty/foot-operated-starter-switch.html

You'd just need to conect your (4-gauge or larger) positive battery cable through it. It'd work awesome, only drawback is you'd just have full power or off.

 

[jace]

that doesn't sound very safe.... so what your saying is without a speed controller, it's full speed or no speed? how would i stop?

 

[jace]

i couldn't use a potentiometer for the gas peddle to control voltage? which, would control speed, right?

 

[Doc Sprocket]

Yep- full on, full off. Neck-snapping, dirt spewing, tire-frying acceleration from a standstill! I don't believe you're going to find a potentiometer capable of that much current.

 

[anderkart]

so what your saying is without a speed controller, it's full speed or no speed?

how would i stop?

Yep, full or nothing.

To stop you'd just let off the button and hit the brake pedal, just like driving a car.

 

[anderkart]

that doesn't sound very safe....

That motor is designed for 48-volts. If you just used a single 12-volt battery, the motor would still run fine, it'd just have less power and speed. This would make it much safer/easier to control the kart with the on/off push-button throttle system.

Then after you got used to riding the kart and wanted more power and speed, you could add 1, 2 or 3 more batteries (wired in series) to get up to 48-volts, then you'd be getting full power and speed from your motor.

 

[r97]

I would not suggest using the on/off switch. Another member on here had problems with the contacts inside the switch fusing, making it so the switch would not disengage... bad. If you want to use that motor to its full potential you are going to need to either spend some money on a controller (I have no clue which one that would be), OR you can look into making your own. I believe a member here offered to provide plans to make one yourself for a reasonable cost. Whether or not that offer still stands I do not know, his thread should be in this section somewhere. If you haven't already, please read the sticky at the top of this section, it is very informative.

 

[91blaze]

Maybe you can do like on an electric golf cart. You can have 4 batteries hooked up to switches. As you push the gas pedal further, it will engage 4 different switches. The first switch will connect only one battery to the motor, then the next will connect 2, and so on. Essentially this is still an on-off type control. Except, if you push the pedal just a little, then you will only have 1/4 power. If you floor it, you will get full power at once.

 

[jdmkid]

^ like gears pretty much. seems like a interesting project, lota thinking gonna be happening.

 

[anderkart]

I would not suggest using the on/off switch. Another member on here had problems with the contacts inside the switch fusing, making it so the switch would not disengage... bad.

I'll bet that guy wasn't using the genuine Cole Hersee brand foot-switch I recommended. Just like any parts, there's lower quality brands sold that are total pieces of trash.

These foot start switches were used before automotive starters had solenoids or a relay. They have huge beefy contacts inside because the 6-volt starters draw twice as much amperage as 12-volt equivalents. I worked at an automotive-electrical specialty/starter-alternator rebuild shop for 17 years. We dealt with 1000's of vintage cars and trucks that used these foot-starter switches, they all had 300 to 500+ amps of current flowing through them. I never saw a single one that stuck on, although I did experience dozens of modern 12-volt starter solenoids & relays that the contacts had fused/stuck on.

But you did have a very good safety point, This type of switch was not designed for constant duty use. It's certainly possible its contacts could fuse/stick-on, especially with the OP's motor. Our gas powered karts have kill switches for use in this situation, and it'd be a really good idea to instal a battery disconnect switch within easy reach of the driver on the OP's kart. There's several different styles of battery disconnect switches available. I'd suggest the OP installs one, no mater what type of speed control system is used.

Edit:
It's be prety easy to instal 2 of the foot-switches I recommended, they would share the load lowering the stress on each switch. You'd just need to wire them in parallel and use a throttle pedal that simply pushed against both switches.

 

[Bluethunder3320]

the 4 switch idea sounds good, but i think you should have some kind of master shut-off that is easy to pull, just in case.

 

[anderkart]

Maybe you can do like on an electric golf cart. You can have 4 batteries hooked up to switches. As you push the gas pedal further, it will engage 4 different switches. The first switch will connect only one battery to the motor, then the next will connect 2, and so on. Essentially this is still an on-off type control. Except, if you push the pedal just a little, then you will only have 1/4 power. If you floor it, you will get full power at once.

That wouldnt work using the OP's motor. 48-volt golfcarts that use this type of speed control system have
4-speed motors with 4 posts to conect all the battery cables, like this pic:

The OP's 48-volt motor just has 1 power and 1 ground post, like this pic:

_________________

the 4 switch idea sounds good,

The problem is 4 batteries would need to connect in series to achieve 48-volts. Each of your 4 switches would have to control both power and ground. It's probably do-able using 4 dual pull/dual throw type switches, triggering multiple solenoids, but it would be very complicated and exspencive for the OP's situation.

 

[jace]

i'll have to talk to my grandfather about it, i'm sure he can get ahold of some type of speed controller for the motor, i'm pretty sure he got it out of some machine he worked on, like most the things in the garage...

 

[anderkart]

Good Idea.

Check out the pics in this google image search link: http://www.google.com/search?q=Brig...4i09QSy0oGgAg&ved=0CEMQ_AUoAQ&biw=783&bih=315
You'll find several pics showing e-Tek motors on bicycles, motorcycles, go karts and even an outboard motor. If you click on some of those pics you'll find that some have info on what kind of speed control system they used on their DIY projects. I didnt research all of them but I found a guy that installed one on a motorcycle, he ended up using a mosfet speed controller (rated at 600 amp) that cost over $1000...

I still think the foot-switch I recommended will work just fine. Lots of barstool racers use simple on/off switch systems with their car starter motors that have similar power/amp-draw as you e-Tek motor. Most of those barstool guys just use a small pushbutton/momentary switch to trigger an RV-Solenoid like the one sold at this link:: http://www.americanrvcompany.com/To...lation-Solenoid-Trailer-RV-Camper_p_2543.html You could use one of those on your kart as another low-cost option too.

 

[sparhawk817]

speed controls are overrated... just sayin.

i've used just dimmer switches, standard from a hardware store on 120 volt ac motors, and you can just run them on the eighteen volt bvatteries for cordless drills and stuff, and wire a few in series. no need to buy a real expensive speed control usually.

 

[r97]

I remember reading some posts on here a while back STRONGLY recommending against the use of dimmer switches as a speed control device. I believe the main problem is that they eat a ton of power.

 

[anderkart]

An automotive dimmer switch can only handle maybe 30-amp's of current before frying.
Most dimmer switches intended for AC-voltage/house-lighting are only designed to handle a max 600-watt/5.5 amp draw.

The push button starter switch i recommended can handle starting car engines that have a 500+ amp draw, and typically last for 50+ years at this task. These switches were not intended for continues-duty use, but I still feel its the best low-cost option for the op's situation.