FS Frame + Cromotor + Lipo

[MadRhino]

He he, soon you will want to upgrade your 18 fet to feed more. 6 Kw is where you begin to feel the power. I don't know how high this motor saturates, but I wouldn't be surprised if it could do bursts of 20 HP. Mine is gonna ride soon, we have a warm week coming that will melt most of the snow.

 

[gensem]

He he, soon you will want to upgrade your 18 fet to feed more. 6 Kw is where you begin to feel the power. I don't know how high this motor saturates, but I wouldn't be surprised if it could do bursts of 20 HP. Mine is gonna ride soon, we have a warm week coming that will melt most of the snow.

Its basically two 9c together... so it should saturate around 16hp.
What external temperature is considered safe on a hub motor? 100º C?

 

[gensem]

Couple short videos

[youtube]mB1t-6BYOsY[/youtube]

[youtube]IGAu6gnHiwc[/youtube]

 

[Accountant]

Its basically two 9c together... so it should saturate around 16hp.

It is not even close to be comparable with 2 9c motors. It is separate product. Materials used are much different.


What external temperature is considered safe on a hub motor? 100º C?[/quote]

This enters into the red zone. when outside temp is close to 100º C inside temp can already be over 200º C.

That is too much, if you want your motor to last 10 years.

High temperature appears with not economical driving; stop and go, acceleration and braking, uphil accelerations.


Try to speed up and than keep the constant speed.

This way of using will destroy something quickly.


Cromotor is intended to be used on high speed bicycles. We are not magicians. You can not use it for 100 mph speeds constantly, and no you can not make 6 feet high jumps.

It is motor for bicycle.

We use it with 72 V and no more than 100 amps current.


60 minute rides with constant speeds up to 60-70 kmh, and motor will last forever.


Aint that enought for daily commuter ?


Racing products are something different.

 

[gensem]

Its basically two 9c together... so it should saturate around 16hp.

It is not even close to be comparable with 2 9c motors. It is separate product. Materials used are much different.

Its a diferente product of course, but its the exact size of two 9C that why alot of people uses 9C´s as reference. So the saturation should be even higher!

This enters into the red zone. when outside temp is close to 100º C inside temp can already be over 200º C.

Ok, so can I consider 80º C in the motor cover safe?

High temperature appears with not economical driving; stop and go, acceleration and braking, uphil accelerations.

Try to speed up and than keep the constant speed.

This way of using will destroy something quickly.

A commute in a any big city unfortunately will have alot of stop´s and go´s and Sao Paulo does have some big hills.

Cromotor is intended to be used on high speed bicycles. We are not magicians. You can not use it for 100 mph speeds constantly, and no you can not make 6 feet high jumps.

It is motor for bicycle.

We use it with 72 V and no more than 100 amps current.


60 minute rides with constant speeds up to 60-70 kmh, and motor will last forever.


Aint that enought for daily commuter ?

Im running 6kw so im below the 7.2kw figure you just posted and my top speed is in the 70-75km/h range.

Vladimir the issue is that.. People that are ordering the cromotor arent looking for a a reliable commute they want motorcycle power in a bicycle envelope without having to deal with reduction and chains.

3x pie sized hub motor anyone?

Regards

 

[gensem]

two more

[youtube]rvLJhlZbEdc[/youtube]

[youtube]mb8OOFBc2EA[/youtube]

 

[Accountant]

Im running 6kw so im below the 7.2kw figure you just posted and my top speed is in the 70-75km/h range.

Vladimir the issue is that.. People that are ordering the cromotor arent looking for a a reliable commute they want motorcycle power in a bicycle envelope without having to dealing with reduction and chains.



Yes, it can be done, but I just do not want anyone to get hurt.

I see that you are having FUN, but this way of using electric bicycle is entering the RED zone.


Motorcycle power demands for motorcycle construction.


I feel like we released the monster..


Please use very cold head when testing Cromotors limits, ride safely, use high quality rims,tires, brakes.... stay on the safe side

 

[markobetti]

two more

[youtube]rvLJhlZbEdc[/youtube]

[youtube]mb8OOFBc2EA[/youtube]

great videos , yeah keep safe and walk the red line ) gonna be there in a month with ya ..

 

[gensem]

Really... Are you coming to Sao paulo Marko?
Drop me a line, i ll be happy to assist you.

Accountant that was just sunday testing in week days traffic jam does not allow me to go that fast.

 

[flathill]

Ok... it was just a lame LVC...

WHAT A RIDE!!! It really really fun running with 6kw!
Controller is running ok, I would say its warn at most.
Motor is too hot to touch after 25km, was not scary hot but it was much hotter than I tought it would be.
If I was to drill holes on it is there a pattern that works better?

As usual I had a camera with me, ll edit and upload videos this afternoon

This motor looks the same and it is only rated for 3kw:
http://www.alibaba.com/product-gs/520306146/3000w_spoked_type_Rear_hub_motor.html

I would guess the cromotor is not very efficent at 6kw but they could have modded it. Either way this style of motor looks way safer than the x54xx because of the cover construction. Also the non skewed stator should give about a 1% efficiency bump. Does the cromotor cog at low speed?

 

[Doctorbass]

Gensem, I have long 5 years experience with overpowering hub motor and i can say that power input mean nothing if you dont take account on wich efficiency zone it is running. and the motor temp depend also of that important factor.

Ex, with my X5 5303 ( that i recall is rated 750W nominal motor), i can sustain 11kW continuous without noticing any temp increase at 121 celsius on the stator.... But it is because it was runing right in the max efficiency curve wich is around 80% so 2.2kW of heat and 8.8kW power at the wheel

What i mean is that if you want to know wich MAX power is safe for your motor, you must know in wich area in the motor efficiency curve your motor is.

ex: at 113km/h my 5303 receive 11kW continuous no problem and sustain it.

but.. you will also see that at 113kmh.. that's alot of wind on the wheel and.. motor.. so it help cooling it ( the 2.2kW of heat)

But if i would try the same setup but with 50% of acceleration and braking alot of hill etc.. and that having an average speed of 45kmh, the motor would be like in the 50% or 40% efficiency zone and the power in heat would now be like 6 or 7kW wich can not be dissipated by the motor so overheat would occur.


from my experience i can say that an X5 can be used continuously at any temp under 140 celsius and can also take 180 celsius "accidental burst".
In fact, last year mine accidently reached 250 celsius for few minutes and is still working today.

You must know that once the motor is ramping in temperature, it will become less efficient due to the resistance of the winding incrasing alot and for the same output power at the wheel it will need to dissipate more and more heat and that loop could roast your winding if you dont have any stator temp monitoring option.

Overpowering should be always done with the temp monitoring option period!.. if you wnat to keep your motor alive :wink:

I personally have burst over 294A on my 5305 at 111VDC and it never blown, except that often, the alarm temp is chiming :lol: and i have to reduce the throttle.

Finally, the temp of the hub motor cover mean ABSOLUTLY NOTHING compare to the temp of the stator winding !!

You can have your stator winding reaching 200 celsius while your motor cover is at 60 celsius only... these cover temp take time to rise because the only way they get that heat is by direct infrared radiation or with the air inside.. and it's a bad thermal conductor.

Also, some guys are measuring the cover motor temp with IR thermometer... wich is not really accurate. Aluminum is reflecting heat.. so the heat you can measure will be the heat from reflection of the object around your motor cover and not the motor cover itself. Metal are like mirror for infrared radiation.. it,s like determining the color of a miror in front of you.... it will be teh exact same color as you :wink:

Just keep in mind usually X5 can take up to 140 celsius on the stator no prob without any problem.
( the hall sensor are usually rated 160 celsius and the rire teflon skin are 260 cesius before melt)

Doc

 

[hillzofvalp]

Gensem, which brakes are u using and how are your pads holding up?

 

[markobetti]

Really... Are you coming to Sao paulo Marko?

would like one day , BUT I JUST WANTED TO SAY THAT MY CROMOTOR IS GOING ON BIKE SOON ,
SO I LL DO EXTREME VIDEOS ALSO


Drop me a line, i ll be happy to assist you.

Accountant that was just sunday testing in week days traffic jam does not allow me to go that fast.

 

[gensem]

Doc, how did you install a thermometer in your motors?

 

[gensem]

Gensem, which brakes are u using and how are your pads holding up?

Front is an avid elixir and rear is a avid BB7, pads are going to last forever because regen is doing 80% of the work. Also consider that regen is very hard on rear tire, i mean its not modular its either on or off.
Im think i ll use a 8 pot gatorbrake in the extended genesis frame.

 

[GCinDC]

nice motorcycle racing...

Doc, how did you install a thermometer in your motors?

i'm researching this and have found some links...fyi:
Hobbyking Voltage and Temperature Monitor Review
Temp sensor that's too cool not to share

 

[gensem]

nice motorcycle racing...

Doc, how did you install a thermometer in your motors?

i'm researching this and have found some links...fyi:
Hobbyking Voltage and Temperature Monitor Review
Temp sensor that's too cool not to share

Wasnt really a race... that moto has 1150cc... i said something like this to the guy when we had to stop at traffic light:

Its eletric and its fast but your moto is too big for me to mock with.

Will look into the sensors and see what im going to do to, to be truth is im waiting for CA v12

 

[hillzofvalp]

I Have a front elixir, but have been lazy trying to mount the rear elixir. Are you using high regen settings? Any mods? Does thist motor have stronger regen than a 9C?

 

[gensem]

I Have a front elixir, but have been lazy trying to mount the rear elixir. Are you using high regen settings? Any mods? Does thist motor have stronger regen than a 9C?

Im using regen on settings 2 (high) and im seeting 15a of regen. I got the controller from lyen and as far as I know only r12 mod was done. Im not sure because I was using the 9c with 52v ping, but its strong enough to stop you at 50mph without much trouble.

 

[John in CR]

Does thist motor have stronger regen than a 9C?

That would depend on the windings of each, but to the extent it has more torque per amp, then it will have more braking force per amp allowed too.

 

[oatnet]

This motor looks the same and it is only rated for 3kw:
http://www.alibaba.com/product-gs/520306146/3000w_spoked_type_Rear_hub_motor.html

I would guess the cromotor is not very efficent at 6kw but they could have modded it. Either way this style of motor looks way safer than the x54xx because of the cover construction. Also the non skewed stator should give about a 1% efficiency bump. Does the cromotor cog at low speed?

Here is that motor's test sheet vs the one Markobetti supplied for the CroMo:

 

[flathill]

Thanks Oatnet. Looks like the alibaba one is a faster wind unloaded, but the torque figures don't make sense. The testing methodology is different. The cromotor is supposed to have some secret tweaks...

Do u know which kv cromotor that datasheet is from?

 

[oatnet]

Thanks Oatnet. Looks like the alibaba one is a faster wind unloaded, but the torque figures don't make sense. The testing methodology is different. The cromotor is supposed to have some secret tweaks...

Do u know which kv cromotor that datasheet is from?

That is for the 13kv CroMotor, back before we found out it they actually got 9.26kv. Look at line 1, and divide the 623.2rpm vy 48.22v, and you get 12.92 RPM/v. The AliBaba one is a stunningly low 15.67kv.

-JD

 

[gensem]

Ok... I did some more testing with a bunch of different 250cc motorcycles and 6kw is not enough to beat thoses guys. I think 8kw ll do, but 9kw would be better to have some room.
Im seriosly thinking about doing some holes in the covers but im not sure about the size of the holes, is a pattern like allowing max air flow?
https://sites.google.com/site/shelbyelectro/motors/mods/ventilating-a-hub-motor

One think that is odd is that my 18fet 4110 loses alot of punch as soon as it gets warm, it has to be something related with the shunt, would be glad if someone could elaborate.

 

[hillzofvalp]

You need to situate them so they scoop the air. Near the top of the cover drilled from the front of the bike to the top of the motor is the slant you're looking for. It's not worth finding out exactly how they should be, because the theory and testing is lacking, in my opinion, on ES. Just drill some holes and u will see improvement. Put them in the scientifically proven optimum place and it might be an extra 20% improvement, I'd guess.