QS 3000w midmotor

Looks like the 90h comes with water cooling very little in size difference makes its perfect choice for a karter.
H3d029d0045db4353a4bb23b1286c700bF.jpg
 
Looks like a great choice for my 500+lb cargo bike in long steep mountain road country.

Compared to the Lightning Rods XXL??

The radiator cooling factor really opens up torque possibilities when top speed is not a goal.
 
I do wish QS used unique model numbers, so hard to track what's what when Watt capacity is so nebulous a factor
 
Cargo bike, damn that motor could push a desert bike about upto 60 mph or so and have a pop at a small trailer on the back.

Problem with such a bike is the sprockets gearing a bike wheel down to slow speed high torque for a efficent ride aint no easy task, where as a gokart wheel is easy as its so small.

Someone needs to make a stand up scooter with one these beasts even the 70h be evil on a 6.5inch rim
 
Ianhill said:
Cargo bike, damn that motor could push a desert bike about upto 60 mph or so and have a pop at a small trailer on the back.

Problem with such a bike is the sprockets gearing a bike wheel down to slow speed high torque for a efficent ride aint no easy task, where as a gokart wheel is easy as its so small.
As mentioned I want low speed high torque only, maybe 22-26mph max.

Even slower bumping along the desert or forest trails with 500lbs

which is why little wheels are NG hitting logs and ditches.

I figure equivalent OD to a 24-26" bike wheel, would love a bouncy fattie, but needs to be very puncture resistant

 
Maybe, but knowledge is necessary even if not sufficient.

Personal and family obligations are the limiting factors currently, but won't be there forever.
 
Is anyone using these motors with belts? I haven't found what belt spec they're using.

Are rear sprockets available for reasonable prices?
 
8M20 SUPERTORQUE
 
Im trying to confirm the bore of the water cooled sprocket now i think its 3/4 bore with a 3/16th key but unsure, i thought the 138 70h was a 17mm but it turned out to be 20mm.
 
Where is the best place to source these from? Been a while since I was in the market, and the shipping is just insane. Is there any US domestic stock of them?
 
Can anyone tell me, if the QS138 70H motor has got a temperature sensor, and if yes, which one?

When mine arrived from QS (bought it ~1 year ago) , they said they had matched the motor to the controller already,
and when I had a look at the settings, the motor sensor was set to "0" (= no sensor).

In the Kelly KLS settings, there are 3 options to choose from:
"0" for "no sensor"
"1" for "KTY84-130"
"2" for "KTY83-122"

As I said, when it arrived it was set to "0".
When I tried setting it to "1", the "monitor" function of the Kelly controller software showed unrealistic high values.
When I set it to "2", the monitor function shows values which could be correct.

But with this setting the controller sometimes stops working because of high motor temperature.
The "max temp" setting is at 130°C, and when I measure the temperature at the outside of the motor, is is never higher than 70°C. So I am suspecting that this temp.sensor setting is nonsense.
 
First, do you have a temp sensor? Earlier you had to ask for one to get it, now i don’t know of it’s included as standard. Are there any extra wires on your hall connector except the normal five? If so, you could look up that kelly sensor characteristic, and just measure the output on your wires with a dmm and compare.
 
Depending on availability, it can receive a KTY84 or a KTY83 probe.
It's very easy to fit a probe to the winding by removing the front flange once the pinion has been removed.
 
larsb said:
First, do you have a temp sensor? ...Are there any extra wires on your hall connector except the normal five?

This was a good hint.
I checked this out, and I do have a 6th wire with a "temp. signal" cable coming out of the motor.

The external temperature of the motor does not go up higher than 70°C
(I have put the temperature sensor of my display to the outside of the motor, so that I can observe the temperature when riding)
but the internal temperature seems to go over 130°C (this is the "motor overheat temp. cut off" setting of the controller).

I have no experiences with that-could it be correct that the internal temperature of the motor is ~twice as high as the internal temperature measured by the QS motor temp sensor?

So it looks like the motor overheats due to some wrong settings ?
(I have posted screenshots of them in my build thread)

PS:
For those who didnt read my whole build thread:
Vehicle weighs 99 kg, driver too.
Transmission ratio motor/rear wheel is 11/70 teeth.
 
That temp difference seems higher than it should be.
Easiest way to find out is to ride it for 5 or 10 mins around the 130deg reading and let it rest for about 3 mins watching the two temps, the 130 should drop early on and the 70 would rise initially.
The two would have to be within about 10 deg of each other in 3, or max of 5 mins of rest to be legit I reckon.
 
For several experiments with an internal probe and an external probe I can tell you that there is no difference.
Only the probe placed on the winding will display the temperature rise more quickly than the contact probe on the motor casing, but in both cases the temperature is the same.
Even a temperature of 70°C seems high to me, what transmission do you have?
 
toolman2 said:
That temp difference seems higher than it should be.
Easiest way to find out is to ride it for 5 or 10 mins around the 130deg reading and let it rest for about 3 mins watching the two temps, the 130 should drop early on and the 70 would rise initially.
The two would have to be within about 10 deg of each other in 3, or max of 5 mins of rest to be legit I reckon.

Been thinking of that, too, but I cant read the internal temp so easily-the Kelly App doesnt work on my phone, only on the laptop.
 
To find out more about the temperature problem, I have double checked the temperature readings, and they definitely seem to be wrong:
I didnt use the motor for 24 hours, to be sure it is totally cooled down.
Then I measured the outside temperature of the motor with a laser thermometer.
Result: 20°C (room temperature)
But when I opened the Kelly Controller Program and used to "monitor" function to check the internal motor temperature, it said 31°C.
This was with the setting "Motor temp sensor type 2"
When I changed to "Motor temp sensor type 1", the result was even worse: 97°C !

Also when driving, the motor temperature outside is always much lower than what the motor inside temperature sensor shows.
When the controller cuts off because of high temperature, the outside of the motor has not more than 55, 60°C, the absolute maximum I measured was 68°C.
I cannot believe that really inside there are 130°C and outside only 68°C.
I can imagine there is a small difference, because of the better cooling on the outside (by wind etc), but not 100% difference.

Does anyone have values how hot the motor can be without getting damaged?

The kelly software allows a maximum setting of the motor shut down temperature to 170°C-
I am considering setting this value to that maximum and see what I will measure at the outside then if the controller stops the motor again...
 
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