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Are pendulums hard on the motor?


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I've been practicing doing pendulums on my RS HT for about 4 days now.

I'm up to 12-16 pendulums in a row now. I normally spend 15-20 minutes a day practicing. 

Yesterday for the first time, my RS started to beep and then started to tilt back on me to the point if not being able to ride it. This was about 20 minutes into pendulum practice. 

I stopped and turned off the RS, then i turned it back on. It rebalanced, so i went for another 5 minutes problem free.

The temperature of the wheel according to EUC world app was about 68°C-70°C. The battery level was at 56% according to EUC World app at the end of this session.

So just wondering if doing pendulums for 20 minutes hard on the motor? Or should i do shorter practice sessions? If practicing pendulums are not hard on the motor.....what do you think caused the beeping and tiltback.

 

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Yes, it's hard on the motor. You're accelerating as hard as possible followed by braking as hard as possible then repeating this over and over. The wheel doesn't get to cool down because there's no decent airflow created. You could always practise riding backwards instead.

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The absolute worst thing you can do to the wheel for overheating. I recall seeing a video where the man was testing the heat shutoff point of various wheels. I think it was during me researching for my Ks18. How he did it was: continued pendulum until the wheel failed or overheat protection kicked in. Long story short.... don't do that! Pendulum is fine, a little bit, but you may want to mix in something else to bide your time as well. I do as @mike_bike_kite suggested, and ride backwards or mix it up with various stupidity.

Edited by ShanesPlanet
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Ok thank you guys! I didn't think realize this would build up so much heat. I'll do shorter 5 minute practice sessions with normal riding in between.

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18 minutes ago, Cary said:

Ok thank you guys! I didn't think realize this would build up so much heat. I'll do shorter 5 minute practice sessions with normal riding in between.

why not just work it into the routine? You know, pendulum a few times and then roll backwards a bit. pendulum then roll forwards to some 180's, and so on. Its the demand of the motor without reprieve or airflow, thats hurting it. Just keep an eye on your temps is all. The temps arent great for exacts, but if you know what temp is says it is, when it beeps, you can just watch for that. DOesnt really matter what it's measuring exactly, its for reference. 

Found that vid

 

Edited by ShanesPlanet
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27 minutes ago, ShanesPlanet said:

why not just work it into the routine? You know, pendulum a few times and then roll backwards a bit. pendulum then roll forwards to some 180's, and so on. Its the demand of the motor without reprieve or airflow, thats hurting it. Just keep an eye on your temps is all. The temps arent great for exacts, but if you know what temp is says it is, when it beeps, you can just watch for that. DOesnt really matter what it's measuring exactly, its for reference. 

Found that vid

 

I will practice type of routine from now on. I guess i really stressed the motor for the last week. Hope i didn't cause any permanent damage. Twice  i even heard a funny electronic noise screech coming from the motor just briefly. But it rode normally after.

 

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On 1/5/2021 at 6:40 AM, Cary said:

The temperature of the wheel according to EUC world app was about 68°C-70°C. The battery level was at 56% according to EUC World app at the end of this session.

Another thing to note... I believe (correct me if I am wrong) the temp reading you are seeing in the EUC World app is the control board temp.  If you are generating alot of heat in the motor you might not get a warning except for abnormal behavior/failure.

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On 1/5/2021 at 6:40 AM, Cary said:

My RS started to beep and then started to tilt back on me to the point if not being able to ride it. This was about 20 minutes into pendulum practice. 

The temperature of the wheel according to EUC world app was about 68°C-70°C.

So just wondering if doing pendulums for 20 minutes hard on the motor?

That's normal.

You gradually created 70°C board temp, and the EUC alerted you. No damage is expected from this. Respect the beeps, let her cool down, and carry on :)

(Some older EUC models had issues with melted cable insulation etc, but there are no reported problems of this type for MSuper RS...)

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On 1/5/2021 at 12:40 PM, Cary said:

So just wondering if doing pendulums for 20 minutes hard on the motor

Beside all that already written here the burden for the wheel depends very much on how hard or smooth one can do the pendulum.

Doing it like 

will cause not too much burden... ;)

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On the motor? No.

There's nothing you could do to the motor that wouldn't fry the board or motor power cables a thousand times before.

But pendulums heat up a wheel (mosfets/board) extremely fast. So don't overdo it:)

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I bet you're treating it like that mten. The mten is so wicked fun to pendulum and never really go anywhere. It seems to take it in stride pretty well too (67v420wh). I bet you're swinging your new wheel like a boss and its just complaining like a litte **tch. Like others mentioned, just heed the alarms and show it whos king and how this Sh** is gna go down. WHen it beeps, ride like the wind and curse it for a few moments. The air flow will help, and then back to beating your moneys worth out of it.

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Keep in mind that a motor just starting to turn is pulling all the current it can get, it’s effectively a dead short to its power supply. Not only are you low on fresh cooling air, but you’re asking your components to work very very hard indeed. From the MOSFETs and their drive circuits to the batteries and the wires going to the motor. The motor itself could probably care less cuz it has mass and a rim to dump heat into, up to a point of course.

We all know that these wheels were carefully engineered to have plenty of design margin even at the cost of performance. Right? Surely they’ve reduced the low speed max current to allow for timing tolerances and avoid punch through from current crowding in the emitter fingers of the MOSFETs (Veteran may have done that actually, the Sherman is reported to be a bit sluggish off the line). And they did over spec and heat sink the catch diodes to handle the voltage and heat generated by the repeated max allowed flyback current? They spent the extra dollar and installed 10AWG motor wiring so it doesn’t heat up and melt the high temperature insulation too. And the wiring connections are super solid and don’t work themselves loose. Sure they did! Or it would have blown up already.

I’m not implying that these things shouldn’t pendulum all day because they probably can... but I’d rather do that with an 800USD mTen3 than a wheel that costs thousands because I have no guts when it comes to my wallet. And design margin costs money. Or performance. Usually both.

Edited by Tawpie
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MTen3 with its 10" tire requires far less motor torque to achieve the same acceleration (e.g.: pendulum-reversals), and so its electrical system is far less burdened than a fullsize wheel. (But, the peak current is lower, and top speed is lower...)

I've enjoyed abusing my MSX and learning about its stall-current-limiting behavior, FYI below:

ACtC-3dpMPE2rx9BsI6u55vetDbq_82T-0RGXzU2pvEjigGy4bLmHXucHbGH7wlET5JJ48IoUZ-D67EBMWTUDcvMX0XTJ25_iN3jQ_10Vh0ef9RgayRfHOiD1OrjNXXhFZ3vnlE8uq1EKyeu74Bu0WoV6FUojg=w942-h915-no?authuser=0

 

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