brushless motors

[andyken]

What limits the voltage for a brushless motor?


I have a 1950kv on a 4s esc, can this motor handle a 6s esc?


I also got a roller with no esc, 2200kv motor...


It was on a 6s 120amp esc, which fried...


The motor doesn't spin free?


It turns but it feels like a stepper motor, lumpy like its breaking thru the magnet field?


Is that normal? don't want to fry another esc...

 

[Guest]

You need to find the specs on the motor. They are all rated different.

6s would spin it crazy fast. That's 1950 rpm per volt. Almost 50,000 rpm... I doubt it...

 

[andyken]

You need to find the specs on the motor. They are all rated different.6s would spin it crazy fast. That's 1950 rpm per volt. Almost 50,000 rpm... I doubt it...

So the roller I got had a 6s esc [water fried it] and a 2200kv motor...that would be rated like the 50,000 you were saying.

And the working set up I have is 4s 1950kv and be 27,000 rpm..?

The 6s set up is in a buggy, and the 4s is a truggy.

I think the buggy was rated @65mph and the truggy @45mph.

On the truggy I want a little more speed, I'm thinking a pinion change or bertter lipo's.

 

[Guest]

Yes 27000 would be correct. It is possible to run in the 30,000s. You want a high c rating to handle the load. It's trial and error. You can gear up until it starts getting to warm.

 

[Guest]

The leopard 5692 1340kv can handle 8s. That gets into the 40k rpm range. Just gotta watch the gearing & temps.

 

[TTH]

What limits the voltage for a brushless motor?ave a 1950kv on a 4s esc, can this motor handle a 6s esc?I also got a roller with no esc, 2200kv motor...

It was on a 6s 120amp esc, which fried...

The motor doesn't spin free?

It turns but it feels like a stepper motor, lumpy like its breaking thru the magnet field?

Is that normal? don't want to fry another esc...

That is exactly right...you may have a 4-pole or more motor. Most 2-pole motors turn smoothly.The term for what you are feeling is called "cogging" as long as it is a smooth transition between poles and there is no grinding or crunching you should be fine.

 

[andyken]

That is exactly right...you may have a 4-pole or more motor. Most 2-pole motors turn smoothly.The term for what you are feeling is called "cogging" as long as it is a smooth transition between poles and there is no grinding or crunching you should be fine.

It seems ok but the car will not roll or coast, like there is no neutral ..?

Seems odd.

Like if it was moving it would stop or hard brake at neutral on the radio?

 

[aqwut]

What limits the voltage for a brushless motor?- find spec and maximum RPM, as well as the ESC.

I have a 1950kv on a 4s esc, can this motor handle a 6s esc?

- depends what brand motor, it could be rated 40, 50, 60, 65K rpm.

I also got a roller with no esc, 2200kv motor...

- if it is a el cheap brand, you may want to keep it around 35-40K.

It was on a 6s 120amp esc, which fried...

- gearing is too high or ESC is too weak. have to check the amp draw on the motor and battery.

The motor doesn't spin free? the rotor or stator may have came apart due to excess heat build up.

It turns but it feels like a stepper motor, lumpy like its breaking thru the magnet field?

- depends on how many poles, the more poles the more notches you will feel. Higher pole motors usually have more torque, but less RPM.

Is that normal? don't want to fry another esc...

You have to think Watt/pound & SPEED. Also need to know if your motor/ESC/BAT can handle it.

 

[nsjames]

ok, it's pretty simple.

Volts will make the motor want to turn faster. (KV rating)

Turning faster will make it work harder against your given load.

Thus, increasing volts will increase your watts.

usually you're going to see an amperage increase, unless you do something crazy like double your voltage.

Anyway, the bottom line is that your motor will have a maximum voltage and amperage, This is the maximum wattage that your motor can handle.

Keep under this limit.

Watts=Volts x Amps

highly recommend you getting a watt meter and using it. it will record peak amps, that is if your ESC doesn't do logging.

personally I find watt readings much more accurate than trying to gauge a motors temp, but I'm looking at this from the standpoint of an airplane guy. We got all kinds of cooling, so temps aren't a problem, but you can still melt the windings of the motor because you're simply pushing too much current through them and the resistance is just too high.

 

[andyken]

The car is a almost new HPI Vorza...all stock.

HP Blur 6s 120 amp esc and tork flux 2200kv.

The story was it had one or two battery packs run [6s 5000mah] .

It went thru a puddle and fried the esc.

Guy was totally new to rc, car is very clean.

The car rolls easy without motor, it needs a lot of effort to push it.

It doesn't just coast...not sure if it was the motor that caused it, or the water.

All the other cars I have can roll/coast with no power..?