Getting back in the game, suggestions pls!
#17
ok here is a few things you should know and others just dont know..
17.5 is always a sensored motor..around 2100kv to 2450kv
then you have timing advanecement. I see people running 40 degrees of timing in stock class
Lipos.. there are 2 C rats you need to worry about
constant what the battery can deliver at a constant rate..ie 2500mah with 50c/100cb// thats 125 amps constant and 250 amps Burst say 10 seconds or so..\\ so C rate is 2 things .. constant and burst..
just to add to your confusion ..LOL
17.5 is always a sensored motor..around 2100kv to 2450kv
then you have timing advanecement. I see people running 40 degrees of timing in stock class
Lipos.. there are 2 C rats you need to worry about
constant what the battery can deliver at a constant rate..ie 2500mah with 50c/100cb// thats 125 amps constant and 250 amps Burst say 10 seconds or so..\\ so C rate is 2 things .. constant and burst..
just to add to your confusion ..LOL
#18
my aforementioned issue was the sensor wire! back in business!
I am no expert which you can see from the OP, but from my limited understanding, sensored has an extra wire:
amazon.com/Atomik-RC-Brushless-Motor-Sensor/dp/B00I03LAPI (sry still cant post direct links)
btwn the ESC and motor, that "monitors" the armature in the can, which improves low RPM efficiency and prevents low RPM cogging. the technology is apparently getting better, but there were talks i read about that a sensored motor *could* be less effiecient, but *could* also provide improved braking?
sensorless doesnt have this wire, the powerband isnt as smooth but is supposedly more efficient?
someone PLEASE correct me if I am wrong with any of the above, but that is my understanding.
but having limited time running and experiencing both sensored and sensorless, the only *REALLY* noticeable difference to me was the powerband when the car is moving very slowly (think 20% throttle and less) - it was much smoother with the sensored.
amazon.com/Atomik-RC-Brushless-Motor-Sensor/dp/B00I03LAPI (sry still cant post direct links)
btwn the ESC and motor, that "monitors" the armature in the can, which improves low RPM efficiency and prevents low RPM cogging. the technology is apparently getting better, but there were talks i read about that a sensored motor *could* be less effiecient, but *could* also provide improved braking?
sensorless doesnt have this wire, the powerband isnt as smooth but is supposedly more efficient?
someone PLEASE correct me if I am wrong with any of the above, but that is my understanding.
but having limited time running and experiencing both sensored and sensorless, the only *REALLY* noticeable difference to me was the powerband when the car is moving very slowly (think 20% throttle and less) - it was much smoother with the sensored.
#19
Sensored/sensorless:
Brushless motors use 3 electromagnets in the stator. In order to turn the rotor, they have to be powered in a certain pattern/speed, so that the magnetic fields push/pull the rotor just right.
A sensorless system has no information about the position of the rotor to the electromagnets at 0 RPM, so the ESC cannot send the correct pattern to the motor, but uses a generic one. As RPM builds up, a kind of feedback signal builds up in the motor wires that the ESC can "read", so with higher RPM it works better and better and the pattern gets more and more efficient.
Sensored motors have hall effect sensors that know the exact position of the rotor all the time and use an extra cable to pass that information to the ESC, that then can send the correct power pattern regardless of RPM - even from standing still.
Brushless motors use 3 electromagnets in the stator. In order to turn the rotor, they have to be powered in a certain pattern/speed, so that the magnetic fields push/pull the rotor just right.
A sensorless system has no information about the position of the rotor to the electromagnets at 0 RPM, so the ESC cannot send the correct pattern to the motor, but uses a generic one. As RPM builds up, a kind of feedback signal builds up in the motor wires that the ESC can "read", so with higher RPM it works better and better and the pattern gets more and more efficient.
Sensored motors have hall effect sensors that know the exact position of the rotor all the time and use an extra cable to pass that information to the ESC, that then can send the correct power pattern regardless of RPM - even from standing still.
#20
Tech Fanatic
Joined: May 2013
Posts: 824
From: windsor ontario
That's a shame, I have a B5m that I am putting up for sale this week after doing the M conversion and not even running a lap with it. I have no place to run it. My suggestion if you are running it on dirt, don't go much faster than a 13.5 turn motor.
I put this car on carpet with a 7.5 turn (it was still a B5 not B5m) and was moving at about 1/4 speed and decided to see what would happen if I hit it hard. 1/4 speed and the car went over backwards and very quickly. Point is with these cars you can easily overpower them. But slipper clutch adjustment is very important unless you want to show off and do donuts.
I put this car on carpet with a 7.5 turn (it was still a B5 not B5m) and was moving at about 1/4 speed and decided to see what would happen if I hit it hard. 1/4 speed and the car went over backwards and very quickly. Point is with these cars you can easily overpower them. But slipper clutch adjustment is very important unless you want to show off and do donuts.





