The Unofficial 'CroMotor' Owners Tech-Tips Thread

[Rovi]

Hey guys,
thanks for all your information. I know that the motor is normally used for 48V and 300-400A (manufacturers statement).
For a smaller rim it´s to late now, because the motor is already fitted and on the way back to me.
On next weekend I will be at a quarter mile race (with my motor bike) and hope to find some guys who use electrical power.
So what do you think about the Kelly controller?
I think it´s the best controller to play with different voltages and amps.
So the max power of the battery can be up to 200A at the end ... but at the earliest in 2016 .

I know that there will be more efficient motors that the Cromotor for the triple of the price like: DC series wound 1 but this motor is to heavy (190lbs) for my bicycle project. Therefore I want to go with the "Biest"

 

[Rovi]

Hey guys,
thanks for all your information. I know that the motor is normally used for 48V and 300-400A (manufacturers statement).
For a smaller rim it´s to late now, because the motor is already fitted and on the way back to me.
On next weekend I will be at a quarter mile race (with my motor bike) and hope to find some guys who use electrical power.
So what do you think about the Kelly controller?
I think it´s the best controller to play with different voltages and amps.
So the max power of the battery can be up to 200A at the end ... but at the earliest in 2016 .

I know that there will be more efficient motors that the Cromotor for the triple of the price like: DC series wound 1 but this motor is to heavy (190lbs) for my bicycle project. Therefore I want to go with the "Biest"

 

[Rovi]

Rim is ready!

15,1 kg

 

[stryjk]

please tell me your source for the rim and spokes.

 

[Rovi]

Hey Stryjk,
the source is http://www.speichen-zentrumniederrhein.de/
I send them the motor and told them what I want to have.
2.15" x 21" rim, painted white color
4mm spokes painted red color
and they did it in 4 weeks.

Andre

 

[bigsi]

hi Doug

I have been running a cromotor at 100v for the last 2 years I'm 215 pounds. in the summer it has been nothing but great it's been ran in the extreme heat in the rain in the mud I do not have any test results as far as numbers but it's still going strong nothing's burned out knock on wood so if I had to get another motor for another bike it would be a cromotor. check out my thread

I have no doubt that the cromotor is one of the best motors out there (that doesn't require extensive modification to use), but it is also one of the more expensive and there is a long wait to get one. I would like to compare it to others, and the only way to objectively do that is using performance curves.

Look at the qs v3

 

[Rovi]

Here you will found some values of the cromotor with different weel diameters on different voltage levels:
http://www.eride.me/eproducts/motoren/#cc-m-product-9641108599

Download Datenblatt zum Biest ....

180A @ 125V = 22,5 kW (Peak)

 

[kiwiev]

Hi Guys bit of NOOB question what is the second plug for from motor?

And is the white wire not used on the hall?

Thanks in advance

cheers Kiwi

 

[ridethelightning]

hi kiwi.

youv got 2 plugs there, each has a separate set of hall sensors. the +5v and Gnd should be common to both. cro motors come with a spare set of halls.

i have found some of the halls to be broken on arrival with these motors,so its worth popping them open to check everything is ok, and maybe to upgrade the phases and perhaps install correct temp probe for your controller while your there.

the white wire is a thermistor wire.

 

[kiwiev]

Thanks ride the lightening much appreciated

What kw rating can you run at before you have to vent these hubs.

Apologies if this has been asked before

Cheers Kiwi

 

[ridethelightning]

it probably depends on a lot of factors, like wheel size, weight,ambient temps, hills ,headwinds etc.

if you have an adaptto and a tempsensor, its pretty good at rolling back the power before it gets anywhere near the critical temps.

id estimate 10-12 kw peaks, perhaps up to 15kw depending on the 'terrain'
these things can take serious power for quite a long time before they get warm. i remember a quote somewhere..."designed fo going at 70kph uphill for half an hour before getting hot..."
my 2c

 

[kiwiev]

Thanks Ride

I'm happy with 6kw continuous and 10kw bursts

I like riding at around 40kph and more distance

Cheers Kiwi

 

[Alan B]

My CroMotor is marked 3kw, and I was told 4kw is okay continuous by the purveyors in Croatia. I have run 6kw peak, but it doesn't last long (climbing or accelerating). I'm not pushing it too hard for rock solid commuting and long life. It gets fairly warm at times, not really hot so far.

The problem is that power into the controller/motor is not a good indication of heating in the motor. The main cause of heating in the motor is current from I squared R losses. Motor current makes torque. So what really heats the motor is the torque you make with it. This is why hard acceleration and steep climbing heat the motor the most. More torque, more heat. The speed makes a little heat from core losses, but in most hubmotors the torque making current is the dominant heating source. So once you get up to speed, the torque loading drops off and the heating does too, unless your speed is so high that it takes a lot of torque to maintain it.

The best bet is to watch the temperature, that's the real story (if the sensor is measuring copper temperature). Limiting the phase (motor) current will control how quickly the motor heats up. As Luke has shown, putting crazy current into the motor will heat it instantly.

Just to put things in perspective, my CroMotor's resistance was given as 93.3 milliOhms. (I have not verified this value). If we take that value, and apply 100 amps of phase current we get (from I squared R) 933 watts of heat. How much can it dissipate? It can absorb that into the thermal mass for awhile, but eventually it has to radiate all the heat, and the flow path is poor with the air gap etc. I don't know but I doubt that it can dissipate that much heat long term without getting too hot. I've set my max phase amps to 120 since more than that causes the front tire to lift off the pavement which isn't something that I need my commuting machine to do. At that current the motor heating would be about 1350 watts. OK for a short time but not continuously. How much power is that? Depends on the speed, due to the back EMF. At low speeds it is not a lot of power at all.

Take care and be safe.

 

[kiwiev]

Thanks Alan

That's quite informative

Like you said I really have to monitor motor temperature to how I ride.

Cheers Kiwi

 

[ccmdr]

With the V3 Cromotor I'd highly recommend opening it up and sorting a few potential issue's.

1) Ensure the hall sensors have been correctly soldered to the relevent wire. Two wires in my motor were held via only heatshrink which conked out my Adaptto mini after an autodetect . The vibration working the hall and wire apart under load, but when you check the halls manually unpowered they read fine!!

2) The temp sensor isn't soldered, I found mine with just the wires wrapped loosely around the legs, again just heatshrink compression!

 

[ridethelightning]

+1
there are definately some quality controll problems with the cromotors.
iv seen crazy stuff when iv opened up some of them.
busted halls from assembly, wiring hanging free, temp sensor held in with some kind of yack's earwax
but dont get me wrong, they are an awesome solid unit once they are sorted.

 

[Allex]

Do you mean cromotor or actually QS motor?
I bet Cromotor have better quality control

 

[ridethelightning]

believe it or not, yes I mean cromotor.

the one qs i have is faultlessly made, with much thicker stock phases and a better axle design, but thats not really a fair sample size to make assumptions from.

of the six or seven cromotors iv seen opened, at least 3 of them had major issues, with broken hall legs, bad glue, loose wiring etc.
the glue, or should i say 'grey matter' that held the 10k thermistor in the windings crumbled at the touch. there is no way it would have lasted a day without coming loose.
also, with at least one of them,the cover sealent had been broken when they had opened it for some reason, and was not resealed.

if i needed another motor now , it would be a qs v3 type hands down.

 

[Allex]

Good to know!

 

[ccmdr]

+1 on the crumbly grey setting compound. Replace with a High Temp silicone/gasket sealant.

Also remember having to re-secure the loom inside the hub from too much sag (not from trying to minimise bend radius!). When things go saggy it's time to strap them up or look for a new model :wink:.

Liberal amounts of high temp bearing grease on reassembly helps things slide together (setting the bearings) and with weatherproofing benefits too.

 

[Microbatman]

Wiring for Crystalyte 18FET 4115 Controller to Cromotor

 

[Rovi]

How to kill a CroMotor?
First test were awesome.
I started with 48V DC ... everything was ok but I do not like the top speed!
So I rise up to 96VDC ... much better top speed and normaly I should stop here but
no risk no fun!
So I increase the voltage to 144VDC
Enjoy the video:
https://youtu.be/JuyvykF4KZw

Everything in no load modus.

150A fuse blown away .
The rest I don´t know at the moment.
The first fire impulse came from + Bat of controller

 

[pucksterpete]

Awesome!!!

 

[parabellum]

Good job! What controller did you use?

 

[Icewrench]

That is a very nice short film.
I hope it was a low budget production.
Bravo.