A
Anonymous
Guest
.
paultrafalgar
10 kW
Getting "403 Forbidden" on that link, Nuts.
A
Anonymous
Guest
.
TylerDurden
100 GW
Links work for me... Paul, perhaps check your firewall, ISP and *cough* 'parental controls'. :?
Good stuff, Nutz.
Good stuff, Nutz.
A
Anonymous
Guest
.
TylerDurden
100 GW
I wuz pondering on propane just yesterday... funny. There are pressure-washers for indoor use that run on propane.
Might be the ticket for the lightweight/hybrid/enclosed/leaning/trike/trailer/frankenthing.
Might be the ticket for the lightweight/hybrid/enclosed/leaning/trike/trailer/frankenthing.
spinningmagnets
100 TW
Honda makes a line of 4-stroke engines as small as 25cc, and including 35cc, 50cc, etc. They're used in weed-wackers, tiny 110V generators, water pumps, etc. The garden tiller is $400 but it includes a 90-degree drive (290 RPM output) with an axle on the left and right, plus a manual lever-actuated clutch. Just an option...
http://www.hondapowerequipment.com/...ection=P2TL&modelname=FG110AT&modelid=FG110AT
http://www.hondapowerequipment.com/...ection=P2TL&modelname=FG110AT&modelid=FG110AT
A
Anonymous
Guest
.
paultrafalgar
10 kW
It would be interesting to know what power output we would need for an ebike. Assuming that you would run the gen all the time you were pedaling (rather than just when the battery were flat), that equates to the consumption, in my case about 12 watt/hours per mile. Say the voltage of the battery were 24, then that means you need to generate about 500 mamps continously, doesn't it? It's always struck me that a VERY small generator could do that. Where am I going wrong?nutsandvolts said:...
This is rather interesting, a tiny generator for model airplanes that produces 800mA, and they have small alternators.
And this is bizarre, tiny alternator generating power from blood flow.
spinningmagnets
100 TW
I have been interested in the series-hybrid configuration for some time, but only as a range-extender for an EV, where the trailer is only used on rare occasions.
Gasoline engines are easily converted to run on propane, but I would recommend doubling the cc displacement to roughly get the same power as the appropriately-sized gasoline engine. Concerning sizing the generator...
It depends on what you want to accomplish. As many here know better than I, a motor sized large enough to handle desired accelleration power without any significant heat occurring, would be larger than neccessary during cruise mode, and range would suffer. If we make the motor smaller, so that it gets a little warm on accel, it will cool off during the 90% of the rides "cruise" speed.
Then if we raise the input voltage from the motors constant-duty rating, we can use an even smaller motor, which may have the benefit of being lighter and cheaper. Each bikers use-profile must balance temporary heat build-up against cruise-mode heat-shedding ability.
Adding a gasoline engine to turn a series-hybrid generator (on-board APU, or on a trailer) can be small enough that it only provides range extension, but so small that even if miles are doubled (for rare special trips) the battery pack is still depleted. In this case, I would recommend the gen output watts be equal to the wattage rating of the motor being used.
If you wish to size the series-hybrid gen to provide unlimited miles, you can use a very small battery pack as a "surge tank" to smooth and level demand/output , but the watt rating of the gen should be approximately double the motors wattage.
This is based on an Idaho university series-hybrid experimental Taurus that was run by a motorcycle engine. During accel, the motor drew amps from both the small battery pack/capacitor and the gen. During cruise the motor only used the battery, while the gen recharged the battery and a large capacitor. (I checked the link from my files but its no longer active, its from the early 90's)
If you accellerated frequently with insufficient "battery charging" cruise time (such as in "downtown" city driving), the small battery would gradually be depleted, and you would have to pull over and idle to top-off. This use-profile would require a larger engine/gen and a larger battery pack to achieve uninterrupted use.
At a minimum, a 25cc gasoline engine, or a 50cc converted to propane "should" be more than adequate. I would definitely recommend the 4-stroke for reliability and longevity (no oil/fuel mixing, much better bearings, much cleaner exhaust, and quieter).
If you wish to use the edger motor for the initial experiments, it might be easier to put it on a trailer. A tiny automotive alternator (Geo Metro?) can easily have the voltage regulator hacked to output 52V to feed a 48V battery pack. Free "trash-day" treadmill permanent magnet motors (PMM) typically run off of 90V DC. You could size pulley diameters to have it output 52V...Just a few thoughts....best of luck !
[edit: added link] http://www.qsl.net/ns8o/welcome.html
Gasoline engines are easily converted to run on propane, but I would recommend doubling the cc displacement to roughly get the same power as the appropriately-sized gasoline engine. Concerning sizing the generator...
It depends on what you want to accomplish. As many here know better than I, a motor sized large enough to handle desired accelleration power without any significant heat occurring, would be larger than neccessary during cruise mode, and range would suffer. If we make the motor smaller, so that it gets a little warm on accel, it will cool off during the 90% of the rides "cruise" speed.
Then if we raise the input voltage from the motors constant-duty rating, we can use an even smaller motor, which may have the benefit of being lighter and cheaper. Each bikers use-profile must balance temporary heat build-up against cruise-mode heat-shedding ability.
Adding a gasoline engine to turn a series-hybrid generator (on-board APU, or on a trailer) can be small enough that it only provides range extension, but so small that even if miles are doubled (for rare special trips) the battery pack is still depleted. In this case, I would recommend the gen output watts be equal to the wattage rating of the motor being used.
If you wish to size the series-hybrid gen to provide unlimited miles, you can use a very small battery pack as a "surge tank" to smooth and level demand/output , but the watt rating of the gen should be approximately double the motors wattage.
This is based on an Idaho university series-hybrid experimental Taurus that was run by a motorcycle engine. During accel, the motor drew amps from both the small battery pack/capacitor and the gen. During cruise the motor only used the battery, while the gen recharged the battery and a large capacitor. (I checked the link from my files but its no longer active, its from the early 90's)
If you accellerated frequently with insufficient "battery charging" cruise time (such as in "downtown" city driving), the small battery would gradually be depleted, and you would have to pull over and idle to top-off. This use-profile would require a larger engine/gen and a larger battery pack to achieve uninterrupted use.
At a minimum, a 25cc gasoline engine, or a 50cc converted to propane "should" be more than adequate. I would definitely recommend the 4-stroke for reliability and longevity (no oil/fuel mixing, much better bearings, much cleaner exhaust, and quieter).
If you wish to use the edger motor for the initial experiments, it might be easier to put it on a trailer. A tiny automotive alternator (Geo Metro?) can easily have the voltage regulator hacked to output 52V to feed a 48V battery pack. Free "trash-day" treadmill permanent magnet motors (PMM) typically run off of 90V DC. You could size pulley diameters to have it output 52V...Just a few thoughts....best of luck !
[edit: added link] http://www.qsl.net/ns8o/welcome.html
A
Anonymous
Guest
.
liveforphysics
100 TW
Propane is an awesome fuel for IC engines.
You lose something like 14% in power due to the air that is displaced by the propane fuel, but it has outstanding anti-knock properties, so you can easily more make up the 14% loss through higher compression, which also improves economy greatly. On little engines, this often just means decking the head to decrease chamber volume to the intended size, and it's very simple and easy.
Propane = fail in 2 strokes not because of the danger of it lighting in the pipe (that is less of a danger with propane than gasoline), but rather because the lubrication for a 2-stroke comes from the oil mixed in it's fuel. Oil doesn't mix into propane, and the engines with oil injection tend to be much larger than the scale for E-bikes. Otherwise, 2-strokes pretty much kick 4-strokes asses in every way.
A little 1-2hp honda 4stroke motor could be easily tuned to make 3-4hp, as they are kept very de-tuned for the sake of being idiot proof in the worst of operating conditions. For these flow rates of propane, you will need a liquid/vapor converter of some sort (I think BBQ size may work ok), and then a way to meter it in relation to throttle/rpm. Normally a propane carb setup is called "mixer", and they are found on millions of forklifts and generators, but I've personally never seen one in the 1-4hp size range. I'm sure somebody has gotta make one though, or worst case, it wouldn't be too awful to build from scratch.
Best Wishes,
-Luke
You lose something like 14% in power due to the air that is displaced by the propane fuel, but it has outstanding anti-knock properties, so you can easily more make up the 14% loss through higher compression, which also improves economy greatly. On little engines, this often just means decking the head to decrease chamber volume to the intended size, and it's very simple and easy.
Propane = fail in 2 strokes not because of the danger of it lighting in the pipe (that is less of a danger with propane than gasoline), but rather because the lubrication for a 2-stroke comes from the oil mixed in it's fuel. Oil doesn't mix into propane, and the engines with oil injection tend to be much larger than the scale for E-bikes. Otherwise, 2-strokes pretty much kick 4-strokes asses in every way.
A little 1-2hp honda 4stroke motor could be easily tuned to make 3-4hp, as they are kept very de-tuned for the sake of being idiot proof in the worst of operating conditions. For these flow rates of propane, you will need a liquid/vapor converter of some sort (I think BBQ size may work ok), and then a way to meter it in relation to throttle/rpm. Normally a propane carb setup is called "mixer", and they are found on millions of forklifts and generators, but I've personally never seen one in the 1-4hp size range. I'm sure somebody has gotta make one though, or worst case, it wouldn't be too awful to build from scratch.
Best Wishes,
-Luke