low KV motor 1.5KW, cheap and waterproof

http://www.wxnaier.com/ProductShow.asp?ID=809



2012823154043934.jpg
 
NE-600 Dimension(height*shaft*diameter): 79*62*178mm
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Doesn't fit right to the 67mm BB width, but the sheet could be bent.

If we take the 450rpm@12V as load rpm, the reduction ratio to the BB would be around 1:20 so 1:4.5 with two-stage or 1:2.714 with three stage reduction.
 
#219 chain for the second stage?

80t #219 sprocket is 200mm (8 inches) diameter.

16t to 80t gives 5:1

That leaves 4:1 for the first stage.
 

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Jim615 said:
I posted a mid drive opinion question in the E-Bike General Discussion section. Being a complete newbe I should have posted it here. I am interested in just such a kit. Can my post be moved or duplicated here?
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I've moved your thread to the Non-hub Motor Drives section, Jim

See this thread, too: http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=42785
 
are they really 3.5kg? and how much of that could be removed? cos at 1-1.5kw max continuous output i would expect to find many cheap motors well under 1kg.
and at 3.5kg i would like to see more like 7kw continuous output.
 
toolman2 said:
at 1-1.5kw max continuous output i would expect to find many cheap motors well under 1kg.
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Unvented, at 1800rpm, with less than 68mm case length and for $185? Feel free to point them out.... :)

But:

At the rated speed of 450rpm the fundamental frequency is only 45Hz, so not much incentive for them to use thin laminations....

There's a lot of unproductive copper in those endturns.... The short stack versions won't be very efficient.
 
80t #219 sprocket is 200mm (8 inches) diameter.

16t to 80t gives 5:1
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If we find a way to build the double freewheel BB drive, then i'm in. Sadly I can not make such an adaptor on my lathe, its dia is too big :(

Miles said:
toolman2 wrote:
at 1-1.5kw max continuous output i would expect to find many cheap motors well under 1kg.
Unvented, at 1800rpm, with less than 68mm case length and for $185? Feel free to point them out....
Click to expand...

But:

At the rated speed of 450rpm the fundamental frequency is only 45Hz, so not much incentive for them to use thin laminations....

There's a lot of unproductive copper in those endturns.... The short stack versions won't be very efficient.
Click to expand...

I agree, which stator thickness would you like miles? 0.3mm or less? The long stack versions don't fit very well, but are worth a try. I'm rethinking my 80-100 KV75 project, it's just too bad that it doesn't fit well.
 
I ran my 80100 8turn WYE wind today with 38Volts input. If i measured right it got only 2000rpm when i put a little load on it. seems like i could gain the same with this motor, which is even cheaper (paid 105€ with tax and shipping), but not waterproof.
 
Miles said:
toolman2 said:
at 1-1.5kw max continuous output i would expect to find many cheap motors well under 1kg.
Click to expand...
Unvented, at 1800rpm, with less than 68mm case length and for $185? Feel free to point them out.... :)

But:

At the rated speed of 450rpm the fundamental frequency is only 45Hz, so not much incentive for them to use thin laminations....

There's a lot of unproductive copper in those endturns.... The short stack versions won't be very efficient.
Click to expand...

http://www.hobbyking.com/hobbyking/store/__17986__Turnigy_RotoMax_1_60_Brushless_Outrunner_Motor.html
-not a bad contender? 58mm case length and $108, rated for 2960w at 7000rpm (crap i know), proly better suited to 1kw at 1800rpm rather than 1.5kw, but there are also countless size choices upwards of this one.

- yes it still needs siliconeing up i spose, but hopefully you can see the value in a motor being 3 or 4 times lighter for the same power :?:
or saving 2 or 3kg?
 
http://www.hobbyking.com/hobbyking/stor ... Motor.html
-not a bad contender? 58mm case length and $108, rated for 2960w at 7000rpm (crap i know), proly better suited to 1kw at 1800rpm rather than 1.5kw, but there are also countless size choices upwards of this one.
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at 1800rpm it has 1800/7000=25,7% of its max power, since torque stays the same. That would be about 770Watts max power. You may only run about 11volts through it, otherwise it runs to fast. I guess this motor is not capable of beating the wind alternator for this reason
 
so if your really after 8NM continuous fully sealed without the fan or open case that miles is used to, then i reckon they all may struggle.
it could be calculated i spose, if a block of this surface area can dissipate say 225w below a certain temp?

but i still believe that 850gram motor would compare well in ability to the mid "300w" size of these motors you posted http://www.wxnaier.com/productShow.asp?ID=795
and like i said there are plenty of choices in the 1.5-2kg rc range that would match the bigger 4.8kg generators ability, but yes the kv is not 50.
-just seems like there are plenty of motors out there that have little consideration for weight cos they are meant to stay put or go on a massive machine, rather than a light pushbike, seems they care a bit more for the kg's when it has to fly..
 
For sure, the Wuxi motors aren't going to win any prizes for torque density... They can be used pretty much as they are, though. With the large diameter outrunners you'd need to rewind them, cut off integral propeller mounts etc.

Anyway, this has got me thinking about a custom motor design for crank drives......
 
I have got an answer from wxnaier. They say the stator stack of the NE-300 is 12mm thick, the one of the NE-600 is 20mm thick. Sadly i've got no details about the KV rating yet, I wrote back, hopefully we get the answer tomorrow.
 
I've got more info on the stator.

NE-300 model:
housing length: 65,1mm
over all stator length (inc. winds): 52.3mm
sheet stack length: 12.61mm

NE-600 model
housing length: 106mm
over all stator length (inc. winds): 60mm
sheet stack length: 25.32mm
 
Miles said:
For:
I'm working on a 5" inrunner design.....
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which stator stack length are you aiming on?


Miles said:
Against:
- Heavy.
- Not very efficient.
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I don't know how it could be less heavy. There's not much material one could remove besides the rotor. Since the seem to use car alternator stator sheets, they should be thin enough to gain efficiency ratios in the 90's.

I'm working again on an angle drive reduction. My tongxin drive ate a grain of sand yesterday, now it's load as hell :cry:
 
crossbreak said:
I don't know how it could be less heavy. There's not much material one could remove besides the rotor. Since the seem to use car alternator stator sheets, they should be thin enough to gain efficiency ratios in the 90's.
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Agreed. As toolman2 said, it's not designed with weight in mind.

Distributed windings means more copper in the endturns. With a short stack, there's an awful lot of inactive copper adding to the weight and reducing the efficiency...

We don't know the lam. thickness but I suspect it's 0.5mm. No reason for it to be thinner at 450rpm.

Absolutely no way will peak efficiency be in the 90's.....
 
the prob with increased stack length is packaging. an angle drive would solve this, but there are other probs popping up, fine tuning positioning of the bevel gears is necessary. otherwise it will be load or inefficient.

with an angle drive both packaging could be compact, and the stator stack could have an ideal legth to dia ratio of 1:1.
 
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