Leaf motor BLDC 800 or Hub motor?

[Hugh-Jassman]

I am trying to engineer a better and sexier version of the Elf car. I asked the Elf car people why they used a hub motor with 1:1 ratio to the rear 20” wheel, and the answer did not make much sense. He said that it was “because they are restricted to one HP.” Yet they claim to be able to climb some incredibly steep hills, with the minimum weight of 150lbs with a driver that may weigh only 100lbs? Maybe 300lbs total combined weight? (So much for the stupid laws that limit the power ratings on the label of a motor). I do not know if they use a geared hub motor, I suspect not, but if they used something like the Crystalyte , it would be more understandable.

I would like to find a way to use gears on one of the Leaf non-hub motors 800w or the 650w. http://www.leafmotor.com/bldc-motor/electric-bldc-motors.html
I was thinking about a Nuvinci but they are expensive and are of dubious performance and weight. Is it possible to apply a two or three speed motorcycle gear box to one of the leaf motors??? But maybe I don't need one?

Actually I may build one of these tilting rear end trike velomobiles and use a jack shaft to gear the motor down to the right speed. But it still maybe desirable to use a gear box. I want to be able to drive a 400lbs (or more) up an 8% grade. (And end up with a top speed of about 19mph (or less) on level ground?). Supposedly it takes 1432 Watts to move 400lbs up an 8% grade at 19mph, before gear losses? http://www.kreuzotter.de/english/espeed.htm

I tried to down load the spec sheets for the Leaf motors and my computer will not open them. I hope some one can show me what the motors are capable of.

I have people trying to tell me that I should just use a 'stoke-monkey' hub motor, mid-drive. What are the pros and cons? Does the lack of gears increase the efficiency more than is lost by having to move slowly (at human cranking speed)? I think the main problem with the stoke monkey may be the weight to efficiency ?....is that it?

 

[Hugh-Jassman]

This is what I have in mind but it should lean into thte corners. and the rider must sit up verticle enough to lean over. The rear wheels will be chain driven.

 

[speedpower99]

Leaf motor sells golden motor product, not to be confused with leafbike motor.
They are heavy and under power, a better one would be Big Block motor.
You can search golden motor mid motor will find more information.
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=29810
http://endless-sphere.com/forums/viewtopic.php?f=30&t=45443

 

[neptronix]

Forget that chain driven motor. I bought one and it was poorly constructed, inefficient and heavy.
Try one of leafbike's 1500w 90% efficient hubs.. if you need more power than that, get a MXUS motor. The MXUS has very similar efficiency. These are the most efficient hubs on the market right now in that power range.

That wattage figure for 400lbs is not even in the ballpark. Try ebike.ca's simulator with a MXUS v2 motor:
http://www.ebikes.ca/tools/simulator.html

Adjust your wheel size for how much reduction you will be doing. If you have a 20 inch wheel but are doing 2:1, set it to a 10 inch wheel.

 

[neptronix]

I'll be damned. I'm wrong about the power usage. It's actually kinda close.

You should still use the ebikes.ca simulator to get the figures you need though. It takes into account more of the electric-side variables that matter.

 

[turbo1889]

Another option you might consider is using a multiple Kw capable motorcycle hub motor and using a programmable controller to keep the total power running through the motor within legal limits but still allow really multiplying up the phase amps for torque when hill climbing in the motors lower end.

For example lets say you used a 4.5-Kw rated 72V high power scooter hub motor that takes a 13" scooter/motorcycle tire. Normally you would use a controller with such a motor that would allow for motor phase amps to reach nearly 200-Amps with a battery side Amp limit of 65-Amps or so and you would have an electric motorcycle that could really move. For a lower total power build within e-bike legal limits you still use the same motor and you still use a large powerful controller that can handle phase amp multiplication that goes all the way up the that 200-Amp level when the motor gets bogged down when climbing a hill to get the full torque such a motor is capable of but you program in a much lower Amp limit on the battery side thus ensuring you stay within legal total power limits but you still get the bottom end torque if needed when hill climbing (and also you don't need a great big battery that can handle sustained 65-Amps pull on the battery end).

Don't know the legal limits in your area but in my state the legal power limit for it still to be a bicycle by the letter of the law is "2-brake-horsepower maximum" which is equivalent to 1.49-Kw physical output power ("brake-horsepower" defines a motors physical output power not the electric power input). Thus in my situation I would examine the motors performance graphs and figure out what battery side amp limit I should program in to ensure that I stayed within that limit (knowing the general performance curves of such motors on a 72V system that would probably end up being about a 25-to-30 Amp limit on the battery side).

Basically use a much bigger motor and controller and just dial down the Amp limit on the battery side and thus tapper off the middle to top band of the motors performance but still keep all or nearly all of the high torque capability of the bigger motor on its bottom end.

 

[Hugh-Jassman]

This is the kind of rear-end set up that would work, but it will take some thought to know just how to do it.

[youtube]https://www.youtube.com/watch?v=gCVFfhCErlg[/youtube]



http://i812.photobucket.com/albums/zz44/GoldenMotor/BLT-800powercurve2.jpg

 

[Hugh-Jassman]

is it possible to use one of these motor in sted of a hub motor?
http://www.cloudelectric.com/category-s/332.htm


thanks guys......

Another option you might consider is using a multiple Kw capable motorcycle hub motor and using a programmable controller to keep the total power running through the motor within legal limits but still allow really multiplying up the phase amps for torque when hill climbing in the motors lower end.

 

[Skalabala]

is it possible to use one of these motor in sted of a hub motor?
http://www.cloudelectric.com/category-s/332.htm


thanks guys......

Another option you might consider is using a multiple Kw capable motorcycle hub motor and using a programmable controller to keep the total power running through the motor within legal limits but still allow really multiplying up the phase amps for torque when hill climbing in the motors lower end.

Do you want to use it with sprocket and chain or lace the shaft directly onto the rim??

 

[Hugh-Jassman]

I want to use trike wheels, and slp them onto the shafts

see this video for the basic idea


https://www.youtube.com/watch?v=gCVFfhCErlg