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some may know that my 900 watt beast motor blew up on a hill, pulling my rig with me walking besides it. tsk tsk. these currie motors are not ventilated, and are poor candidates for cooling solutions, given my power/weight/size requirements.

living in so cal, it's hot all the time, and i prefer to have a motor that is ventilated open with a fan for optimal cooling. worry about dirt/debris entering the motor is second. i've been doing a lot of research, and there aren't very many options for a high powered motor with a 10mm shaft, to directly mount the original currie sprocket on. so, i'm looking at motors with a bigger shaft, with an eye to put in a reducing method, using jaw coupling/spider assemblies, to fit my #25 chain setup/investment, if i cannot find a 7/8ID sprocket, made for #25 chain. comments/referrals invited.
the yk43b, yes, the same. my theory is this, regarding power: if you have more than too much, then when you don't need it all, it's plenty. right, the high draw is just mainly starting off, then once up to speed, barely have to tweak the throttle just to keep moving. the other is, i'm gearing up. stock was, let's see, 90 tooth drive sprocket, driven by a 11 tooth stock currie sprocket. the smallest sprocket i could find was this one that fit the 7/8 shaft referenced in the line drawing for the motor, from mcmaster-carr ( ... s/=18dee65 ) and the transmission will have 14 teeth on both sides, , for 1:1, so really it's geared up to 20:90 at its simplest. yes. more speed, but still have plenty of power, on my un-small-car scooter. hee..
20-90 ratio should be ideal , gain some top speed, and the motor will never get warm no matter what kinda hills u climb,. much like an industrial build except the motor u bought is actually capable of more power than most industrials.
i think they screwed up their website-- i look at the page for the motor, and click on add to cart. now i have an invoice for a BRUSH HOLDER for the motor for 99 dollars? I thought i was buying the MOTOR for 99 dollars. dang it.
so, as voltage goes up, the amperage draw of the relevant motor goes down. theoretically, the same batteries i have would give a longer run time at a higher voltage configuration, no? my current stock of batteries are 6 of the 12 volt, 12 amp-hour rating, lead-acid. i was using them in a 3 bank 24 volt config, for 36 amp-hours. i could also wire them as 36 volts, with 2 banks, for 24 amp hours. or even 72 volts at one bank, for 12 amp hours.
The motor will accept whatever amperage the controller puts to it. Now if you are light on the throttle it will last longer. If a motor is rated 30a than that's what it can handle safely but it will draw as many amps as it can up to its rated rpm or overvolted rpm. Then draw more amps based on load and controller capability. Higher ah is better but I wouldn't use below 36v. I am changing a mx500 to 48v because the motor and controller I want to try is only available in 48v.
david coffin wrote:so, as voltage goes up, the amperage draw of the relevant motor goes down. theoretically, the same batteries i have would give a longer run time at a higher voltage configuration, no? my current stock of batteries are 6 of the 12 volt, 12 amp-hour rating, lead-acid. i was using them in a 3 bank 24 volt config, for 36 amp-hours. i could also wire them as 36 volts, with 2 banks, for 24 amp hours. or even 72 volts at one bank, for 12 amp hours.

NOOO// the controller regulates the amperage, as laundry said above.. you are still better off in most cases with a lower voltage system , because you simply have to carry less batteries for the same AH//
example / 6 batteries in parallell is 12v 72 ah ( 12 ah batteries for this example )
running a 30 amp comtroller and a 12 v motor , ur run time will be insane
now , take the same 6 batteries, and run series , u now have 72 v 12 ah
your run time will normal , 12ah supply..
NOW the advantage to the 72 v system is that you are running 72 volts times 30 amps or 2100 watts
on the 12v system you are running 12v times 30 amps or 360 watts..
BUT YOUR NOT RUNNING 30 AMPS , you are running 200 amps
so 200 amps times 24v = 4800 watts , alot of power in a small scooter
were you to run a 72v motor , 72 volts at 200 amps you are now running 14,400 watts//
SO it all balances out , Until you decide to over volt the motor/. Because controllers for scooters are widely limited to 60 volts, its simply less effieicent to carry extra batteries to overvolt at a higher voltage.Ive tested it all , NO ONE in the history of this forum has build a powerhouse at higher voltage , the fastest karts and scooters were always below 48v .. this also ties into rpm per volt , or KV as they call it in rc motors.. a 24 v motor spinning at 3000 rpm is getting over 100 rpm per volt , a 72v motor spinning at 3000 rpm is getting less than 50 rpm per volt.. SO , if you wanted to gain 1500 rpm , which is easier to do ??? run the 72 v motor at 108volts , or simply run the 24 v motor at 36 v ?? ok im done . GO LOW VOLTAGE < it leaves you with more options .
ok, all. for now, i've ordered from the 36 volt 1000 watt motor. 11 tooth initial sprocket, connected to a 14 tooth transmission that drives a 90 tooth final drive. what's the final ratio? i've tried but don't know how to do the math.

edit: aha. tells me that the gears in the middle don't matter. it's still 11 tooth to 90 teeth ratio.. but wouldn't torque be improved? or no difference?
do those Unite motors have a timing bias on the brushes? when hooked up to forward voltage, are the brushes timed for greater efficiency in that direction of rotation, as opposed to lesser efficiency when the power leads are reversed?
just had a thought. this motor i bought is nominally a 36 volt motor, for close to 3000 rpms at full. i fully know the rpms will DROP if i run a LOWER voltage through it. i'm wondering about the power requirements, if i run it at 24 volts (motor shouldnt get hot at all, yeh?), does it suck up more juice at full throttle and shorten the battery life, or is it the other way around?
that yk43b, my1016 36v 1000 watt motor, and all my lead acids (6 of them) reconfigured for 36 volts, 2 banks, 24 amp hours. so far, have gone 10 miles up and down hills and around back to my house, making sure not to run under 32 volts (as i think the yk43b doesn't limit to prevent battery damage) and 8 miles on the flats with the throttle at its lowest, and it pushes me happily, and doesn't go under 35 volts, then, for that distance. wednesday, i have an extreme distance trial coming up, one way to 32 volts at rest, and that'll help me set the tone for my battery discharge curve. motor gets hot, so i added a big fan atop the motor, and it helps reduce it to a slightly burning temperature rather than a hissy hot temperature whenever i touch the motor, and this is in the daylight, 100 degrees outside. i also added a scoop to the side of the motor, to force air through the vents on one side of the motor to exit the other side of the motor, when i am in motion. pictures will come soon, promise. my only issue is charging the batteries, only have a 24 volt and 12 volt chargers, so i am charging the batteries piecemeal, manually, using smart chargers.. it'll be a while, them 36 volt chargers are expensive..
my rat scooter as of today. lots of motorcyclists on the road giving me thumbs-up. heh. the things i got to do to cope with desert-like heat here in Southern Cali/Lousy Angeles..
the yk43b up front for cooling
scoop with vents on motor, to out other end
battery box, see high clearance underneath
front view
right side view of motor deck
left side view of motor deck
coming up
right, that motor does not have an internal fan, does it? so forcing air through the motor from vent to vent is necessary, yes? and yeah, that whole road warrior series is my inspiration, as well as junkyard wars (lots of junk i have in garage to put to good use)...
Yes I don't think it has internal fan. Air induction definitely help, but if I were you, I will also install the heat sink on the motor. With your fan, air induction, and heat sink...I believe that's the best solution next to liquid cooling.
That hotel pan as the battery tray tickles me a bit David, that's a very smart and creative of you lol.. How did you attach it to the body ? did you weld it?
I also want to know if your s750 already came with the disc brake and front caliper brake? My s500 came with crappy drum brake and I install the disc brake by myself.
i wish i could weld it. don't own a welder, and not so much wherewithal. just basically bolted it down and gravity does the rest.. my 750 already had front caliper brakes, and nothing on the back, so was putting a lot of work onto the front brake. rubber melts fast when its hot going downhill. so that's why i upgraded the back end, once i realized i could since the back wheel hub was already threaded.
went on a distance ride this morning. so it seems a 2 bank 36 volt battery is comparable to a 3 bank 24 volt battery. i think i went a bit further, as the yk43b doesn't seem to have a low voltage cutoff except for the one at 21 volts, so answered my own question as to whether it would cut off according to the battery pack voltage sensed, (31.5 for a 36 volt pack, 21 volts for a 24 volt pack, 17 miles i did, 8.5 downhill and 8.5 uphill (I live in the west end of san fernando valley in california, so my house is considered uphill, as evidenced by the los angeles river going east down the valley, downhill) i hope i didn't damage my batteries, as i had it reading down to 24 volts before i quit and walked the rest of the way home. we'll see..
ok.. i have various ages on my batteries, and despite that they are all 12 volt 12 amp hour batteries, i like to keep tabs on them individually. will also make charging easier to make connections, since i do not have a 36 volt charger, just 24 and 12 volt chargers, so charging is a little involved for the nonce. also allows for tapping 12 volt fan to the pack, since a dc/dc converter for 36 volts down to 12 volts is another annoyance to think about.see pic, heh, see, MANUAL bms. using a voltmeter
the metamorphosis continues.. replaced the 90 tooth rear wheel sprocket with a freewheel and an 80 tooth sprocket. huge difference. i get speeds of 20 mph on the flats, now. acceleration is affected only slightly, and climbing hills, too. but the unite motor is chugging along great. i think i get more mileage out of my batteries too, since i'm going faster now than with the old sprocket (which was great for hill climbing) and the batteries aren't going down as quickly as i thought they might, since more amps for a lower gearing with 360+ pounds all together. love the freewheel, as i can coast more than i think, the only drawback is the shock when engaging, although i'm getting used to 'tweaking' the throttle ever so slightly to bring the freewheel clutch up when applying power back up from coasting along..

Hi Waxmonkee! Wow, where to start? I'm new to […]