What do you guys think of this combo?

[speedracerrc]

I think this will work well... A winch motor, and robot speed controller...

This motor:
http://cgi.ebay.com/ebaymotors/NEW-MOTOR-WARN-WINCH-12V-KEYED-SHAFT-HEAVY-DUTY-8274_W0QQcmdZViewItemQQhashZitem35a60c1374QQitemZ230419075956QQptZOtherQ5fVehicleQ5fParts

Winch Specs:
http://www.warn.com/truck/winches/src/M8274-50.shtml
(This shows that the actual motor I'm looking at is rated to go to 24V, the bummer is that they list it pulling down 273A when the thing is really pulling... will I ever do that on a go-kart?)

This speed controller:
http://www.robotmarketplace.com/products/IFI-V885.html
The controller can handle up to 120A continuous and even 300A for less than a second...

To see the maximum my controller can possibly push out: 24V(120A) = 2880W = 3.8HP

The motor is rated at 4.5HP, how do I make sure I don't pull that? I'm guessing a fuse like this would do the trick...
http://cgi.ebay.com/ebaymotors/BLUE-SEA-120A-THERMAL-CIRCUIT-BREAKER-7113-LATEST_W0QQcmdZViewItemQQhashZitem2c5109ee17QQitemZ190338166295QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear

Onto the motor math

it's listed at 2100rpm at 12V, that means that at 24V it goes 4200rpm.

I want to go about 45mph at top speed... with 11" tires that is 1352.55rpm

4200/1352.55 = 2.75 gear reduction totally feasible with normal gears...

Does any of this sound insane? I'm also kicking around the idea of a CVT, maybe modifying this to work:
http://cgi.ebay.com/X-2-X-8-R-6-Pocket-Bike-CVT-Transmission-with-cover_W0QQitemZ150387685772QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2303cdf98c
Main thing I'm unsure of there is getting it to actually engage at the lower rpm's that an electric spins at... Even thinking of manually pushing the drive pulley with levers or something similar to a slave cylinder on a tranny...

Any input before I start fabbing? I'm brand new to this but have a lot of mechanical experience and a full machine shop at my disposal... this should be fun.... I'm putting it into a powerwheels mustang!

 

[mike75925]

Oscar?

 

[speedracerrc]

Oops here are the stats on the motor
http://www.amazon.com/gp/product/B002SZ0I9S/ref=pd_lpo_k2_dp_sr_2?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B002T4U6HW&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=1FVHAFJ530DZSSCG2JFS

Factory 12Volt Warn WInch Motor

This bidirectional, 3 post motor has a KEYED SHAFT and is very popular on WARN and many other winches. Shaft diameter is .669 inches

Specs: 4.5 horsepower - 2100 rpm

This motor replaces part numbers 8274, 8796, M3600, MBJ4401, MBJ4401S 3 POST-KEYED SHAFT.

Voltage: 12
Rotation: Reversible
Field Hsg OD: 113.9mm / 4.484in
Overall Length: 225.2mm / 8.866in
Shaft OD: 17mm / 0.669in
Shaft Notes: Long Keyway
Terminal 1 Size: 5/16-18
Terminal 2 Size: 5/16-18
Terminal 3 Size: 5/16-18
Weight 20 pounds

I'm not Oscar, I'm Travis... New here from Everett Wa

 

[mike75925]

yes, i was acting like i answered the door, and defered to oscar (oscaryu1), yelling the aforementioned. he is the main one i know of that deals in electric karts and such. nice to meet you travis, i'm mike

 

[freakboy]

hi mike and travis.... im kyle and were is oskar.. maby tyler can help... or dante... mabey anderkart... idk COME ON GUYS GET OVER HERE lol..... roger....

 

[mike75925]

shruggs. ah, hi kyle, nice to have met your aquaintance.

 

[dpaxson]

well gearing 2.75:1 is probably going to pull some serious amperage, and if you use a fuse, it'll just burn out every time you try to accelerate really hard. Also, that motor controller is designed for a PWM input instead of a normal potentiometer input like in alltrax and curtis controllers. you would have to buy a servo tester to create the signal to run that controller. I don't have any real experience with electronic karts, but I bet a controller designed for a vehicle would be better suited for your project

 

[speedracerrc]

I'm planning to use this circuit breaker
http://cgi.ebay.com/ebaymotors/BLUE-SEA-120A-THERMAL-CIRCUIT-BREAKER-7113-LATEST_W0QQcmdZViewItemQQhashZitem2c5109ee17QQitemZ190338166295QQptZBoatQ5fPartsQ5fAccessoriesQ5fGear
so it won't matter if it blows.

What would you recommend though? I cannot find a higher current handling unit on my own (at least not for less than $500)

I'm not really concerned if I just have to push a button, I can learn how hard I can push it I suppose, of course I would rather have one that can handle all the current the motor can take...

This servo tester is what i will use when I'm not driving it with RC controls...
http://www.robotmarketplace.com/products/RL-SRVTST.html
(which I will do also... I already have a 14mph speed racer power wheels RC vehicle... I can ride in it, but it's more for my son...)

 

[dpaxson]

i would use a golf cart controller, but if you're planning on making it R/C too, then the one you picked out is probably a better bet.

 

[speedracerrc]

Thanks for your input! Can you point me to the cheapest source for the golf cart controllers?

I can easily make a very cheap RC servo turn a potentiometer to make any 5K pot turn, so on second thought... you may have a better solution than I had come up with! I may have been very lucky to find this forum.... I had no idea that larger current handling controllers existed... However looking at them, are they less efficient? PWM seems to be a much less current wasting method than resistance? Do the cart models just dissipate heat when at low throttle? I guess I don't understand how they operate. I know the robot ones just pulse the full voltage at varying speeds to control speed. How do the cart ones do it? Large resistors (potentiometers) would waste energy in the form of heat...

 

[speedracerrc]

Dpaxon, how do those controllers work? I see they need "programming" and some are pre-programmed? How difficult is it to program them and what does it do?

Thanks again for all your help, looks like I will be going this way! I am also looking for a good deal on one, is Ebay the best place?

Also "plug brake" vs "momentary" a brake would be great if it doesn't blow anything up... how well does the brake work? would be cool if I didn't have to make a separate brake... or at least if i had electric assist for low speeds...

I plan to limit the top speeds at times when my son drives it, can these internally limit top speed?

 

[Qmavam]

I think this will work well... A winch motor, and robot speed controller...

This motor:
http://cgi.ebay.com/ebaymotors/NEW-MOTOR-WARN-WINCH-12V-KEYED-SHAFT-HEAVY-DUTY-8274_W0QQcmdZViewItemQQhashZitem35a60c1374QQitemZ230419075956QQptZOtherQ5fVehicleQ5fParts

This speed controller:
http://www.robotmarketplace.com/products/IFI-V885.html
The controller can handle up to 120A continuous and even 300A for less than a second...

Any input before I start fabbing? I'm brand new to this but have a lot of mechanical experience and a full machine shop at my disposal... this should be fun.... I'm putting it into a powerwheels mustang!

I would be concerned about continuous use of the motor,
ask the manufacturer about the duty cycle for that motor.
Have you looked at the Alltrax motor controllers?
http://www.alltraxinc.com/Products.html
When I floor my kart from a dead stop it draws about 250
amps, and this drops as speed increases. Cruises at about 40 amps. (48volts) Here's a youtube link.
http://www.youtube.com/watch?v=5MKjbXltAew
I have new batteries and a stronger motor mount now.
Mike