Curiosity aroused...š¤
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extremeodd
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The downside to those is they are about 6-7in across from mounting hole to mounting hole and about 3-4in thick. In theory, if you replaced the pulley with a sprocket you might be able to mount one in the same place a stock tensioner would go if you made a custom mounting bracket. Not sure if it would be spinning fast enough (or even too fast) but that would probably be the best shot.
Mcdonns
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Couldnāt really find anything, as far as dimensions. In the 2-3hp range, it might be more load than itās worth, but the work to customize may make sense in the 5-7+ arena... Looks like itād still need a rectifier/regulator, as well (again, not enough info to tell). Gonna keep ponderinā it, though. 
extremeodd
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I've done a fair bit of research into these little tractor alternators before I gave up and went with rechargeable 18650s. They all are in the 4-6in wide range and they all require an external regulator but those regulators are simple 2 wire units that are fairly small.
For lighting, a bike light with an external pack is more than good enough with 4-6hrs of run time. If you want a rear light that will never have a battery die, look into induction lights. They work by mounting a couple of magnets to your spokes that pass by the light which generates enough electricity to run the LED.
For lighting, a bike light with an external pack is more than good enough with 4-6hrs of run time. If you want a rear light that will never have a battery die, look into induction lights. They work by mounting a couple of magnets to your spokes that pass by the light which generates enough electricity to run the LED.
JerboaJohn
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I thought about these too few weeks ago and decided at that size, they would be noticeably heavy like 4 or 5 lbs bcs they are stuffed with copper windings and a steel rotor plus the heavy stamped steel case. reliable as hell, but an LED system can be bright, powered by Lipos and weigh almost nothing unless you need 8+ hours on headlight
FNTPuck
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The 212 guys use these to run lights. Not sure how it would work on a chinagirl since you would have to adjust the gearing for the much higher RPM to not overrev it. I have seen guys run waterpumps off the chinagirl magneto so in theory you could run this off it as well.
I plan to run something like this with a control board and lithium battery for no maintenance lights and starter on my big 4stroke build.
I plan to run something like this with a control board and lithium battery for no maintenance lights and starter on my big 4stroke build.
Mcdonns
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Well, FNTPuck, I donāt even know what my final RPM actually is at the output (10T) sprocket. I havenāt opened the crankcase/clutch side, to count āem yet...
Mcdonns
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Iāve heard final numbers from 13:1 to 16:1, but I havenāt actually done that part of the math, yet. Been so durned focused on just gettinā alignments, small bugs anā safety covered that I havenāt dug into the heart.
Thā point of thā PM alternator is essentially tā maybe do a USB power hub, since everything I have is rechargeable. The question always lingers that if I could get everything smooth and reliable, what would be the problem with a hundred-mile road trip. Well, mostly, the issue comes down to a good breakdown kit, and onboard reliable power.
Thā point of thā PM alternator is essentially tā maybe do a USB power hub, since everything I have is rechargeable. The question always lingers that if I could get everything smooth and reliable, what would be the problem with a hundred-mile road trip. Well, mostly, the issue comes down to a good breakdown kit, and onboard reliable power.
extremeodd
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Divide engine rpm by 4.1 to get output sprocket speed. 2-8k engine rpm is approx 487.8 to 1,951.2 what the output sees.
These alternators are typically driven directly off of the machine's crankshaft at a 1:1 ratio and yard tractors typically sit somewhere around 2500-3500 rpm. Keep in mind that rpm is needed for the full output which can be 20+ amps. For our uses, just a few amps should be plenty to run a couple of high drain lights and still be able to charge a small battery.
If you want a better idea of the size of the john deere alternator and some info on wiring it up, take a look at this page:
http://www.n56ml.com/corvair/dynamo.html
Honestly, I think looking at "alternators" is the wrong way to go about making power. Many DC motors can be turned into a generator by simply spinning its output shaft. An old (but not burned up) battery powered angle grinder might make a great donor, its motor is fairly high powered and it comes with an "overdrive" gearbox that conveniently shifts the input 90 degrees so it won't stick out(as bad). Mounting it and regulating the voltage could be tricky but if it dumps out less than 16v at full speed you wouldn't even need to regulate the output. Just hook it up to a battery to smooth out the voltage and run your equipment off of that.
EDIT: Or hell, strap an old drill to the back of the bike and have it driven by the rear tire.
https://hackaday.com/2014/12/06/cordless-drill-turned-into-bicycle-powered-generator/
EDIT 2: Damn, now I'm down the learning about stuff rabbit hole. Looks like it's not too hard to convert universal electric motors (they can run off AC or DC but do not generate current without modifications) that are found in tons of cheap appliances and tools into a generator. My thought was to use an old dremel + flex shaft and do a friction drive off of the rear wheel. A battery powered one would be best as you can use the speed adjuster to adjust its voltage output.
Converting a universal motor
Dremel into DC generator for a gas scooter
https://www.instructables.com/id/DC-Generator-Made-From-A-Dremel/
These alternators are typically driven directly off of the machine's crankshaft at a 1:1 ratio and yard tractors typically sit somewhere around 2500-3500 rpm. Keep in mind that rpm is needed for the full output which can be 20+ amps. For our uses, just a few amps should be plenty to run a couple of high drain lights and still be able to charge a small battery.
If you want a better idea of the size of the john deere alternator and some info on wiring it up, take a look at this page:
http://www.n56ml.com/corvair/dynamo.html
Honestly, I think looking at "alternators" is the wrong way to go about making power. Many DC motors can be turned into a generator by simply spinning its output shaft. An old (but not burned up) battery powered angle grinder might make a great donor, its motor is fairly high powered and it comes with an "overdrive" gearbox that conveniently shifts the input 90 degrees so it won't stick out(as bad). Mounting it and regulating the voltage could be tricky but if it dumps out less than 16v at full speed you wouldn't even need to regulate the output. Just hook it up to a battery to smooth out the voltage and run your equipment off of that.
EDIT: Or hell, strap an old drill to the back of the bike and have it driven by the rear tire.
https://hackaday.com/2014/12/06/cordless-drill-turned-into-bicycle-powered-generator/
EDIT 2: Damn, now I'm down the learning about stuff rabbit hole. Looks like it's not too hard to convert universal electric motors (they can run off AC or DC but do not generate current without modifications) that are found in tons of cheap appliances and tools into a generator. My thought was to use an old dremel + flex shaft and do a friction drive off of the rear wheel. A battery powered one would be best as you can use the speed adjuster to adjust its voltage output.
Converting a universal motor
Dremel into DC generator for a gas scooter
https://www.instructables.com/id/DC-Generator-Made-From-A-Dremel/
Last edited:
Mcdonns
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Well, extremeodd, if mā math check out, that means I should be quite safely below the ~25mph Iād be comfortable never exceeding (not on a bicycle, anyway). Iām running an 80cc China, 11T drive and 32T driven on a 29ā MB, so Iāll never really see motor 8kRPM ā proāly run standard in thā 3k-5k range. Total vehicle weight, right now, stands at 41lbs with a full 3L tank and basic tools. Itās obviously more setup for light cruising to and from modest trail areas (hence the required lights/turns and simple forward-looking cam, and Iām also kinda old ān busted up), and pedal-power while wanderinā around nature.
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