Depends on the rpm and erpm and hubs are especially high in copper losses. But those losses are the same regardless of the load on the motor and can be seen with the Vesc tool in real time data.
If u spin them on the bench you can see how much current is actually lost to iron losses or see if maybe a short within the windings and that’s the issue
Nope, you can overheat pretty much any outrunner by running it at high RPM on the bench at 2A.
Going fast all the time will create lots of heat via core losses. And in that case bigger motors are not the solution since those create even more heat via core losses. You need a motor that addresses this issue via good design choices.
Soooo…I have to make breaks inbetween or modify my board, right?
I kinda don’t want to.
How do the other boards do it?
You can not tell me that all the other high powered boards run without problems, people go fast on them all the time and speed uphill and so on, why doesn’t that work with mine?
Aren’t those motors notorious for getting way hotter than they should?
They’re notorious for apparently over-reporting their temperatures. The LC FB groups are full of complaints. Many are disconnecting the temp sensor and/or cranking up the cutoff thresholds.
That’s such a classic Trampa response. It’s not the product that’s the problem, it’s the fact that you’re using it.
I have these motors on the boards I was racing this weekend and that I generally thrash around the place at higher average speeds for longer durations. I don’t have this problem.
@exx - if LC said to update your settings and you’re not sure what exactly they mean, presumably you’ve gone back to ask for a clarification, right?
Worth adding that making updates to settings and firmwares sort of goes with the territory here… and that includes pre-builts like Lacroix’s. You need to embrace it. You’ll soon find that that side of things can almost be as enjoyable as the riding side! That’s why forums like this exist! 
Yeah, so far no response.
I have asked again, let’s see.
I may have already noticed that tuning and building is apparently a big part of electric skating 
but have a lot of respect let’s call it for the big electronics and such, I’m not really capable of buying replacements if I fuck something up.
Otoh, I got the Davega installed without problems and I’ve taken my Onewheel apart on many occasions and it still works so fuck it.
Thanks guys, this forum is the tits!
I’ll take a punt on what you’ll need to look at @exx, and @Flasher & team can either confirm or correct me if I’m wrong…
Connect with VESC tool or whatever you’re using and make the following adjustments:
Motor Temp Cutoff Start: 110˚c
Motor Temp Cutoff End: 120˚c
Acceleration Temp Decrease: 15% (<-edited)
If this doesn’t help and if you’re fairly certain it is a sensor error (i.e. your saliva doesn’t explode when you spit on the motors after a cutout), then disconnect the orange sensor cable from your motors where it connects to the ESC. Most elegant would be to extract the pin from the JST and insulate it. Least elegant would be to just cut the wire.
Will do, thanks!
I’ll report back.
edit: Will this age my motors prematurely?
How long on average do motors last?
Thanks
Have you checked yet wether you can still touch your motors or not?
Bad advice!
There is a good reason for temp limits and that is to prevent motors to get damaged (potentially at speed) and shorting out or to get mechanical damage while they are operated. There is also the fact that the internal resistance changes with heat and the original FOC detection parameters do not work any longer. That can result in a motor locking up, since the observer has trouble to track the rotor properly.
If you put Temp Cutoff Start and Temp Cutoff End close together, the VESC has no chance to reduce the power early enough to work against overheating. You would basically run straight into cutoff.
In the end esk8 motors are quite small and if you run them too fast or too hard, they will overheat. And the software is there to protect the hardware and you. Some motors are better than others and can sustain the load for longer, but eventually all of them will overheat if you ride with high average speed for a long time.
If there is a 10K temp probe inside the motor, the measured winding temp will be measured pretty spot on and the temp is actually reaching 100°C and you should give the motor time to cool down.
Especially closed motors with no airflow around the stator will build up heat faster and it will take longer to cool them down. On RC drones and planes the motors can sustain a higher power output because of the massive airflow around the coils. That can result in 50%+ more constant power output. If you would shield the airflow, so that the motor is not sitting in the propeller wind, the motor would overheat instantly.
Same goes for liquid cooled motors. If you stop the pump/flow, the motor will overheat.
In esk8 the same physics apply. If you don’t manage to suck the seat out of the stator, it will accumulate and the temp will rise till the cutoff temp is reached. The less airflow the stator gets in touch with, the sooner the problem will surface.
The other issue is a vicious circle effect. The hotter a motor gets, the more internal resistance it gets. More resistance results in more losses and more losses result in more heat etc. At a certain point the temp drifts away and the motor gets hotter and hotter.
TLDR: The problem is not your temp sensor, but the physics of losses inside your motor. Losses need to be cooled away, or they will accumulate over time and the motor will not reach a stable temp plateau. Eventually the FOC parameters do not match any longer and you are entering the danger zone.
Not yet, it’s raining and I’m still stuck at work.
They have been very hot to the touch on previous rides, though.
Does running in BLDC mode reduce motor temp compared to FOC?
Would lowering the KV to put his average speed closer to the peak of the motor’s power curve help to reduce temp?
I have a Nazare and regularly do 12-15 mile rides at average speeds like that, with hills. My motors get hot to the touch but no hotter than on my Trampa or on my own builds, 2 out of 3 of which have smaller motors. Never had a drop out that I recognized as such. I am 165 lbs these days though.
If the Lacroix guys gave you a recommendation I would try very hard to follow it. They have been spot on with all my questions.
No BLDC is less efficient.
There are a few ways to get the temps down. The most effective is lots of airflow around the coils.
The other options is a good balance in between motor RPM (KV) and average speed (application matched gearing). You can also go for more or less airgap (magnet to stator) and some other design features also impact the heat buildup. The combination of all tweaks in the system make the final difference in motor temps. System voltage also has an impact, but it is not as much as you would like it to be.
There are losses and those go into heat and you need to cool them away. That simple…
If you don’t, the heat will build up with a vicious circle effect towards higher temps.
In the end you also have to be realistic of what two tiny motors can deliver in average. It is already quite amazing how much power such boards have and how fast they can go. Non of the typical esk8 motors can output lots of power over an extended period of time. What they don’t like in general is high speed runs for a long time, or high speed hill climbing in San Francisco. What they like is riding with mixed speeds and phases that allow the heat to decrease before it builds up again.
Do you have or could you borrow a contactless thermometer (like one of the IR types)? Maybe you can get access to one that has a high enough temperature range to verify how well your sensors are calibrated.
The temp on the motor housing and at the stator are probably 20+°C apart. The only way to measure the temp at the coils is an internal probe. If both motors register the same temp, the temp probe is probably showing the correct values.
I don’t disagree with the gist of what you’re saying here, Frank, but:
If they’re reporting 100˚c then by your account the can would be around 80˚c and would therefore cause a severe burn in a fraction of a second if it were touched. On the strength of the sheer number of cases I’ve read about, I’m willing to bet that this will not be the case: there will be no burn, it will not truly be at 100˚c.
Now that’s not to say that there isn’t a fundamental design flaw with the LC/MT motors (there obviously is), nor that there is no risk of heat-related damage over the course of time (there obviously is). I’m simply saying that I don’t believe that the situation is as bad as you’re making it out to be.
I will also add that I find LC’s response on the subject (or lack thereof) to be slightly concerning.
Edit: To expand on that last point, what I mean to say here is that when numerous employees independently say something as vague and ultimately unhelpful as, “you need to update your settings”, my cynical mind imagines an orchestrated effort to dodge an issue. Something more substantial would be more constructive and comforting for customers.
Would be good to drop a probe inside, straight onto the windings and then measure the difference in between outside rotor and winding temp. If the rotor sits in the airflow, the temp spread can probably be quite a lot.
All the stuff I try to explain here is general stuff, not related to a special motor form a manufacturer x.
Knowing the actual temp of the windings is a good thing! Otherwise you risk to run them outside the FOC detection parameters or outside the safe motor operating temperature.
If the maytech 6396 motors are on your board, they are well known for overheating extremely quick, my advice would be to lower the current and increase the max temperature, however if you don’t want to decrease your torque I recommend switching motors, but I guess that will void your warranty,