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  1. D

    How much thrust needed for kayak ?

    It would actually make more sense for a kayak paddle wheeler to have just one and to put it on the back, like an outboard motor. It could then be steerable as well, with a pivot that would allow it to pop up if it hits something, or be tipped completely out when I don't need assist. Now if...
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    How much thrust needed for kayak ?

    The towing with a fish scale would actually work pretty well I think, would measure actual force required to go a given speed which I could measure with my phones gps. I know you guys are joking about a paddle wheel, but that could probably actually work without getting fowled up on underwater...
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    How much thrust needed for kayak ?

    I see your point, but having some experience with rc stuff I know they aren't automatically loud, and can be surprisingly quiet. It has a lot to do with using a large prop at lower rpm as opposed to a small one spinning fast. Also, it wouldn't be running all the time anyway, mostly to...
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    How much thrust needed for kayak ?

    My wife and I use some inexpensive 10 ft " sport " kayaks for some recreational boating and are looking for some power assist to extend our range on these slow kayaks. A trolling type submerged motor would not be a good choice due to the shallow and log/weed infested areas we frequent, so we...
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    Solar Powered Canoe

    The easiest recommendation I can give for prop size is just to buy a couple ( considering their low cost ) of different sizes and try them out. The 12x8 is obviously too big, ( I wouldn't use anything that draws more watts than the stock prop ) and I would also stick to sizes where the pitch is...
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    Typical Wh/Mi for an electric kayak?

    I believe a low cost solution for the big gear reduction ratio's needed to use small brushless motors could be rc helicopter parts. A 450 class heli has a main gear reduction around 13 to 15:1, runs in good bearings, and uses decent quality rc motors. The motors typically are around 3000kv...
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    Typical Wh/Mi for an electric kayak?

    I am thinking of doing a tiny outboard for my 10 ft kayak in the simplest possible way, ( r/c motor with long straight shaft ), but am missing the key part of the calculation, what rpm to design for. I am planning on using a r/c airplane apc-brand prop in 5x3 size, and want to put about 75...
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    Building my own trolling motor.

    From what I have been able to determine, a trolling motor normally turns 1200 to 1400 rpm. That motor is a 730kv, so on 12v will be turning 8760 with no load and shouldn't be loaded down to less that 75% of that or 6600 rpm. This means your going to need to do a gear reduction of around 4.5...
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    Overvolting a minn kota trolling motor

    The calculation is easy. 2x voltage means 2x amperage, so if you had say 200 watts at 12v you now have 800 watts at 24v. Assume the original 12v setup was correct with the motor loaded down to 75% of no load rpm, a likely 70% efficiency, and 50 watts of waste heat. The 24v version will try...
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    Smalest friction drive ever? Assist experiment

    I tried to search that motor and came up with nothing, however, unless its around 500kv its not going to work well at all on 3s and will probably overheat since its being lugged down to way below its best rpm. In brief: Motors run at their best at around 75% of no load rpm. Since that motor...
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    Hub motor efficiencies - Amp limit vs voltage limit

    Your not quite right here. The controller provides varying average volts,( and with it current and rpm), but if you ran the controllers output on an occiliscope, you would see that the peak volts, ( and with it current ) are close to full battery voltage, about the same number you would see if...
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    Prop for low power drive?

    I was'nt in town for that event, although I live only about 4 miles from there. I understand that one of these low watt systems is'nt going to push the bike without pedalling at a decent speed, the point of a " commuter booster " as I understand it is to still need to pedal but your speed...
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    Prop for low power drive?

    The efficiency of props has greatly to do with: a) prop design. ( all are not created equally!) b) rpm. A large prop spinning slow is much better than a small prop spinning fast. c) disk loading. The more power you put to a given prop, ( raising rpm, see b), the less efficient it becomes. In...
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    Prop for low power drive?

    This is my first post here, but I'm an rc airplane guy and have to wonder why for a low power " commuter booster " drive why not just use an rc motor and prop setup? It wouldnt be terribly difficult to make keep the rider safe from the prop and would sure be a simple system. As an example, I...
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