I'm new to the whole MB scene but since I'm now an epileptic I built one and plan on using it as my main vehicle so i don't put others at risk of getting hit while I'm driving a car. Got a good winter priced deal on a 4 stroke china motor that runs like a champ and will push my old mountain bike about 33 mph down the road. currently I have a great 200 lumen flashlight for a headlamp and a turn signal/brake light combo that both run on batteries. What I'd like to do since this will be my main vehicle is add on a small SLA battery and run a fog lamp for a headlamp and use the battery to power all my other electrical stuff. I also am don't want to have to worry about recharging the battery off the bike with an outlet so have been looking into ideas for a solid generator I can charge the battery off of. I ran across this generator on ebay Wind / Hydro Generator - 12V Generator - 160 Watts Peak Power - 60 Watts Cont. | eBay which is supposed to be for a small windmill and was looking for opinions on it. Rigging it up shouldn't be a hassle after all I'm studying for my degree in mechanical engineering right not at school and have spent a good portion of my life working on tanks and w/e else is broke in the army and working on semi's. The rpms seem a bit high but at about 30 mph I'd need a 36:1 ratio to get those rpms which is easily doable. Any thoughts or ideas?
12 volt generator idea
- Thread starter Kahlas
- Start date
The RPM requirements to me would be the stopper. 14,000 for a full 12 volts? what does your lighting system require voltage wise?
A fog lamp will have a good current draw IMO, unless you can find a LED solution. Possibly a small solar panel and a UPS battery? All eBay available.
Anyway my 2 cent.
A fog lamp will have a good current draw IMO, unless you can find a LED solution. Possibly a small solar panel and a UPS battery? All eBay available.
Anyway my 2 cent.
If your willnig to rectify the power generated to charge the battery off the engine, a simple perm-magnet brushless would be a better choice (but a little more complicated) you can find all kinds of rc motors that would be better suited & put out all the power you need for the application. & way easy to rewind to make exactly what you need.
something like this:
Leadershobby.com - Radio Control Hobby Parts Online Retailer and RC Parts distributor
something like this:
Leadershobby.com - Radio Control Hobby Parts Online Retailer and RC Parts distributor
Blue Glow Mini Off-Road Fog Lights
One of these lamps is the plan unless I find something with a bit less current draw. The idea is to have a 12 volt battery running all my electrical and the generator to charge the battery.
As far as getting 14,000 rpms I think it's easily doable. I cruise at about 30 MPH and have 26" tires which have an outside diameter of 80.63 inches(6.719 feet). So 30 miles(which is the distance the bike travels in 1 hour) = 158,400 feet so divide 158,400 feet buy 6.719 feet and you get about 23575 revolutions of the tire at per 30 miles traveled(which i do in a hour at 30 MPH), so the rpm would require you divide that but 60 minutes in an hour for 393 rpms of the tire and with 44 teeth on the tire sprocket and 10 on the motor that gives me 1571 rpms on the output shaft coming from the motor(which seems a little low to me though I'm not familiar with RPM's on small 4 strokes and it does pass through a gearbox/clutch before hitting the driving sprocket) so an 8.9:1 ratio on the engine output shaft will do the job provided that ratio doesn't take too much power from the engine.
I'm sure I can find a small belt pulley to put on the shaft and get the gearing ratio down.
One of these lamps is the plan unless I find something with a bit less current draw. The idea is to have a 12 volt battery running all my electrical and the generator to charge the battery.
As far as getting 14,000 rpms I think it's easily doable. I cruise at about 30 MPH and have 26" tires which have an outside diameter of 80.63 inches(6.719 feet). So 30 miles(which is the distance the bike travels in 1 hour) = 158,400 feet so divide 158,400 feet buy 6.719 feet and you get about 23575 revolutions of the tire at per 30 miles traveled(which i do in a hour at 30 MPH), so the rpm would require you divide that but 60 minutes in an hour for 393 rpms of the tire and with 44 teeth on the tire sprocket and 10 on the motor that gives me 1571 rpms on the output shaft coming from the motor(which seems a little low to me though I'm not familiar with RPM's on small 4 strokes and it does pass through a gearbox/clutch before hitting the driving sprocket) so an 8.9:1 ratio on the engine output shaft will do the job provided that ratio doesn't take too much power from the engine.
I'm sure I can find a small belt pulley to put on the shaft and get the gearing ratio down.
Unless I am missing something it looks like a 500 or 600 can motor that normally sell afor around 10 bucks. Also if I were going to build around one of these I would besure to use one of the more expensive ones with ball bearings not bushings. As mentioned the RC brushless motors are a much better choice, cheaper, ball bearing and last longer. There are schemats on the conversion if you google.
This has caught my attention , but I am not having much luck finding any schematics on how to convert a brushless, or tech specs on those rc brushless motors . what exactly were your search terms ?
This is where I have seen it. I couldnt find the earlier thread where they were home building one. Maybe there are some insights here.Jewel Generator - HeliFreak
I agree with Cannonball2; that ebay post likes like one of those little hobby type motors which are cheap. These little permanent magnet DC motors will act as a very little output generator if spun at high speed, just like stated in the ebay post. BMF
I think if one of these lil brushless motors will generate enough power I could loose my battery or even charge it to some degree, perhaps if that lil motor was driven off of the crankshaft on the right side or even the left /mag side of the china motor , that would open up some serious electrical an lighting possibilities for many of us here . My original concern is to just make my bike more visible in broad daylight an safer if riding at night via brighter better lighting .
this is a problem I for one cannot let go of . thanks for the link , will post any more theorys as I come up with them .
Gary
this is a problem I for one cannot let go of . thanks for the link , will post any more theorys as I come up with them .
Gary
Has anyone ever tried to mount an old Sportster generator to get 12v?
It could be fitted with a gear on the shaft, mounted to the frame, and driven by a jackshaft.
Maybe just driven inline by the drive chain?
It could be fitted with a gear on the shaft, mounted to the frame, and driven by a jackshaft.
Maybe just driven inline by the drive chain?
If your going to add a starter from a sporty why not make it fully functional , an dont you think its a lil big ?
An old Sprotster generator would be fully functional for a 12v system. It would charge a battery, run the lights, horn and accessories.
They really aren't that big. I would have to dig through my shed to find one for measurements, but from what I remember, I don't think they are much larger than 2" diameter and 6" long. (Maybe a little longer with the shaft.)
They really aren't that big. I would have to dig through my shed to find one for measurements, but from what I remember, I don't think they are much larger than 2" diameter and 6" long. (Maybe a little longer with the shaft.)
The Sportster generators are about 3 3/4" diameter, about 6 1/2" long, judging by memory.
They are heavy too.
The starters are more size and weight friendly, especially the smaller '74-'76 Hitachi ones.
They both have field coils in them which require a power source to energize rather than permanent magnets. A generator would them be more user friendly as it is wired to be controlled by the regulator. The starter is not, there is no "F" terminal on a starter. The "F" terminal on the generator is what the regulator is wired to in order to control the field strength of the field coil which is the mechanism in which the regulator uses to regulate the output of the generator's "A" terminal. More current through the field coils = stronger magnetic field reacting with the armature = more output from the generator.
Less current through the field coils = less magnetic strength reacting with the armature = less output from the generator.
The generators do not actually generate power as one would commonly think, they multiply it by harnessing the mechanical energy provided by the engine spinning the armature.
Using a permanent magnet RC motor would be more size and weight friendly.
They are heavy too.
The starters are more size and weight friendly, especially the smaller '74-'76 Hitachi ones.
They both have field coils in them which require a power source to energize rather than permanent magnets. A generator would them be more user friendly as it is wired to be controlled by the regulator. The starter is not, there is no "F" terminal on a starter. The "F" terminal on the generator is what the regulator is wired to in order to control the field strength of the field coil which is the mechanism in which the regulator uses to regulate the output of the generator's "A" terminal. More current through the field coils = stronger magnetic field reacting with the armature = more output from the generator.
Less current through the field coils = less magnetic strength reacting with the armature = less output from the generator.
The generators do not actually generate power as one would commonly think, they multiply it by harnessing the mechanical energy provided by the engine spinning the armature.
Using a permanent magnet RC motor would be more size and weight friendly.
Last edited:
I have experimented with building wind powered generators to use on experimental aircraft that had engines with no provisons for alternator or generator mount.
Any perm mag field motor will generate when spinning. A favorite was an auto radiator fan, propellor already installed. Kidde car motors work good.
Heater fan motors work good too.
For a regulator, all you need is a tympanium type regulator from a lawntractor or a snowmobile. These are designed to convert AC lighting coil output to about 13.5 volts DC.
Very simple direct wiring, no switch needed .Experience shows that they will also regulate a DC motor/generator.
A good candidate would be a dynamo from a a small Kubota tractor.
Very small size, 10 amps max, and the whole outside rotates. You could fricton drive it right off the tire, or belt drive it off a motor.
Any perm mag field motor will generate when spinning. A favorite was an auto radiator fan, propellor already installed. Kidde car motors work good.
Heater fan motors work good too.
For a regulator, all you need is a tympanium type regulator from a lawntractor or a snowmobile. These are designed to convert AC lighting coil output to about 13.5 volts DC.
Very simple direct wiring, no switch needed .Experience shows that they will also regulate a DC motor/generator.
A good candidate would be a dynamo from a a small Kubota tractor.
Very small size, 10 amps max, and the whole outside rotates. You could fricton drive it right off the tire, or belt drive it off a motor.
Last edited:
Looks like a good candidate, you got any idea where I can get one? I'm gonna check out Google myself but wouldn't mind any help/input I can get. By the end of this coming spring I'd like to have an electrical system I don't have to worry about running low on charge with. That way I can start rigging up the hard part, a sealed box for my turn signal control board, light switches, and bike comp.
oh and do you know what model number that one in your pic is?
Last edited:
This is a standard used on many models of small Kubotas, I have an old G5200 model mower that has one installed.
Google used tractor parts, and you can find multiple websites that can get a used one , as I did for the one in the pic. I paid $60 about 5 years ago.
Or you can buy one new for about double that price.
Google used tractor parts, and you can find multiple websites that can get a used one , as I did for the one in the pic. I paid $60 about 5 years ago.
Or you can buy one new for about double that price.
http://http://www.amazon.com/Permanent-Alternator-15531-64013-15531-64016-15531-64017/dp/B005UOR29I
Cheapest new one I could find. Got any idea on what the model number is on it cause it looks like it will do the job perfectly(actually pushes more amps than I need). I already tried checking out ebay but I guess I'm too much of a herp derp to figure out a good search term there.
Cheapest new one I could find. Got any idea on what the model number is on it cause it looks like it will do the job perfectly(actually pushes more amps than I need). I already tried checking out ebay but I guess I'm too much of a herp derp to figure out a good search term there.
never mind, found some, all new all 106 dollars. That's not incredibly horrid but could be better priced.
eww and they look like I'll need an external regulator also. I'm guessing I can just buy the stock regulator that comes with the tractor and hook it right up. Might take a look at craigs list. Could probably get a who non-running tractor for 100 bucks there. Then I got all the parts I might need.
eww and they look like I'll need an external regulator also. I'm guessing I can just buy the stock regulator that comes with the tractor and hook it right up. Might take a look at craigs list. Could probably get a who non-running tractor for 100 bucks there. Then I got all the parts I might need.
Last edited:
