I want to go faster.

Moderators: robnewyork, bassiclyLouDog, gameboy

By mcneil84cj
#20016
I've installed a 36v controller and 4 - 12v 12ah batteries to my kids razor and it only reaches 10.6 mph.

How can I get more speed from this set-up? New motor?

After running for 5-6 minutes you can smell the motor.

Thanks!
84CJ
User avatar
By bassiclyLouDog
#20018
48v on a 24v motor? smoke. it'll be fun for a couple blocks, but that smelly burnt copper smell will put you to a halt. I tried just using partial throttle...didn't work. not even a mile.
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By aidanworthington
#20025
yes a bigger motor is what you need and a new rear sprocket
most people bolt a 750-1000w motor up top
ontop of the original motor mount
all you have to do is drill 4 holes and bolt it down
and trimm the body work to allow the chain to pass
1000w.png
1000w.png (54.57 KiB) Viewed 2936 times
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By bassiclyLouDog
#20046
I know I bring it up a lot, but 2 small motors can be just as good if not better. Think 2 350watt are almost 20amp current a piece...there's 40amps to play with and the heat can be dispersed over 2motors instead of one. You can also run more volts than with just one motor. 2 24v motors can run up to 72v. On the flip side you run 48v on high amps and not burn out. Of course you'd have to upgrade batteries to run 100amps but you can probably run 50amps easy with what you have.
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By bassiclyLouDog
#20048
Too bad there's no simple way to mount to motors in a pocket mod. Lots of room for batteries. Sit down so the weight wouldn't be as scary. I suppose a face plate and a couple Currie types to bolt in. I just saw a 450 for $45...not a bad deal but again an industrial for$105?! Yeah. No comparison
By mcneil84cj
#20058
I thought of one more question, about the throttle. It's currently the original throttle. would this limit in any way the full potential of the currie 900W motor?

If so, any suggestions on which throttle to use?
By robnewyork
#20065
the throttle plays no part, goin from 36v motor to 48 v pack is 33 percent gain top speed, goin from 24v motor to 36v speed controller yeilds 50 percent,.. if u have the skills id do 900watt motor on 50 amp controlller, gain torque and speed all at once,any hall throttle will work.
By mcneil84cj
#20091
Anyone render a guestimate on how fast the dune buggy will be with the 900 @ 36v?

Plan is to complete the project by New Years. Once complete, I'll post a video of it with confirmed MPH.
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By maurtis
#20098
I used this calculator on my Dune Buggy build and it was pretty much spot on: http://www.compgoparts.com/TechnicalResources/JackshaftRatioCalculator.asp

Once you enter the sprocket sizes, motor RPM, and tire size you can play around with the sprocket ratios to increase speed or torque. The easiest one to change is the motor sprocket, of course.

Is this a 24V Currie? I see a couple online rated at 2,600 RPM at 24V. If that is the one, and you are using the stock gearing at 36V, you are looking at 3,900 RPM. If stock speed is 8 MPH, you should see 12 MPH. That is what we saw on ours when we went from 24V to 36V on the stock motor.

The stock controller is a 20A controller, so the 28A controller will give you some more torque. Not neck snapping torque, but should be noticeable. Running a 50A controller would definitely be an upgrade you feel, without smoking the motor.
By mcneil84cj
#20100
could you point me to a site where I could pick up a new motor sprocket?

Looking for 15-18 mph - approximately how many teeth?

Sorry, that calculator link is a bit more than I can digest (at this point)!

Thanks.
By mcneil84cj
#20117
robnewyork wrote:i dont think on stock controller it will climb much,and tnc is simpler


Sorry, I do not follow.

As previously mentioned in this thread, I've upgraded the controller to 36v 1000W 28amp.

Are you saying there would not be enough torque if I went with a higher tooth count in the engine sprocket?
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By bassiclyLouDog
#20265
your video explains everything a lot better! 48v on the stock 24v motor will fry it..QUICK! running 36v on a 24v motor will give you a 50% speed gain. running 48v on 36v motor will give you a 30% gain. motor current is listed in amps, the higher current, the better performance(speed :) ) The higher amp controller, the more torque it'll produce. The trouble here is 36v controllers are rated between 28-40amps, when you step up to 48v controllers, there are 50 and 100 amp models available.
You alreaday have batteries and a controller, your best route my just be stepping up the motor to a larger 24v. If that doesn't do it, get a large buttocks 36v, run it on 60v lol!
By robnewyork
#20268
run that 900 watt at 36v, and maybe 50 amps if u can find it, kelly makes one, but it will handle 36v 28amps no issue no heat..top speed should be 50 percent gain.
By mcneil84cj
#20500
Would you recommend a different one? My plan is to stay at 48volts, can't go back now.

Also, would you recommend changing the motor or axle sprocket? Changing one with more teeth would make it faster, right? You saw, there is no worry about torque, so for pure speed whats the best option?

Thanks again Rob!
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By bassiclyLouDog
#20505
I'm going to caution again. 24v motor plus 48v equals smoke. Awesome vids but I'd hate to see a project burn out. When you smell burnt copper its usually too late. Check and see how hot your motor is getting. You may get away with such a light test pilot.
User avatar
By bassiclyLouDog
#20513
ran my pocket mod with a 30amp razor controller took less than a mile to fry it, but i weigh a lot lol...good rule of thumb is never more than 1.5X overvolt, but as he says he already went there so thee is no going back lol
By robnewyork
#20521
its the overall watts that count, what motor was it ?? keep in mind a unite 24v 250 watt will handle 60 volts on 10 amps carrying a mouse in a 12th scale rc car ..
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