Brakes failing don’t know why please help

ESK8 Electronics
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41

You have tiny battery problems mate. How strong we can brake depends entirely on how big our pack is. The max amount you can “regen” on a 2p pack is about 10 amps but you can only expect that on a partially discharged pack. If your pack is small the voltage will rise quickly when braking and trigger an over voltage.

It would also be helpful to hear what gear ratio and wheels size you are running. A 270kv motor is like having really tall gears so if you are not using a proper ratio to bring the theoretical top speed down to a level better suited to a 10s2p battery you will have issues.

1 Like
42

Set your motor current max on 60A

Motor current brake max on -60A And your max current on 120A.

Battery current max regen: -10A I think if you go higher then then that your BMS will cut it off.

That was the problem I think you had.

Set your erpm limit on 58 000

And set your throttle curve both at 0% and in a linear line.

43

abec11 97mm

16 to 36 ratio

44

either way was using battery on a hub driven board and it got wet and producing nearly no power now so it is probably dead

45

Yeeww, board was set up as a screamer! With that set up you were pumping massive amounts of current when braking. A battery 3 times the size of yours would have still been struggling with that setup. If you drop down to a 200kv motor the system will draw much less current.

You might be able to salvage the battery. If you have a multimeter you can check the voltage on your P groups and see if one of them is bad.

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46

I am upgrading to a 10s5p Samsung 30q battery from @Tinp123 (he’s a really good builder with good prices) should that work ok with those motors a unity and that battery

47

No, that motor is still to high of a KV value for 10s. A 200kv motor is what you want.

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48

I thought a unity can handle up to 100000erpm

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49

A 270kv motor is like having really tall gears

What is your goal? Are you trying to build a death stick that can reach 50 mph or do you just want a practical board with a 20 to 30 mph top speed? If you want good brakes you need to change the ratio or the motor.

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50

Happy to change ratio have got some 40t pulleys for abec What good motor pulley could I get for Tb motors

51

A 14t motor pulley would work with the 40t but the board will still reach around 36-38 mph so it will be on the fast side. Ideal top speed for efficiency is around 25 mph.

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52

Around 35mph should be fine

what about a 12t though

Also will that help with braking

53

I don’t advise going lower than 14t with a 5htd tooth profile. You get less tooth engagement and the belt will strip.

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54

K thanks a lot do you know where in uk I can source that and what bore is Tb motors 8mm or 10mm

55

Is there any way I could limit the motor to a certain amount of Kev or something

56

Probably 8mm.

The VESC is amazing but it won’t change the resistance in your motor windings. Only way to change the KV on your motors is to rewind them with more turns on the stators.

57

That’s a no

So what do you say I should do except scraping the motors

58

I will second/third or forth what everyone has said and get motors with a lower kv. Yes the unity can handle higher erpm however you are still running the risk of issues.

please read this article about KV for each battery. Only experienced builders/ riders should be messing with kv and battery and speed.

60

The thing about that article is that it is based on a cell being on full charge most the time cells are 3.7v

So 8450/37 is 227kv which is t that far off a 260kv motor Also couldn’t I limit it to 33v or so as then it would work with 260kv fine

62

If “cheap” is your goal, get a KEDA 6364.
If “good” is your goal, get a 6374 from @psychotiller
For something in-between get a @torqueboards 6374 (for single-drive) or two @torqueboards 6355 for dual drive.

Don’t go over 200Kv.