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Micro brushless motor issue HELP

AnimalHippie

RCC Addict
Joined
Mar 27, 2018
Messages
1,250
Location
Ocala, Florida, USA
Ok guys this is what I have going on. I'm fairly new to the RC world. So I don't have allot of experience. The experience I do have is with 1/10 rigs and brushed motors.

I got a few losi micros in a box that were pretty much in parts. The one that I'm working on currently has a losi xcelorin 1/36 brushless ESC and a Spin HO46-8800kv brushless motor. Motor looks like a tiny revolver motor. The other night I got it put together enough to see if I could get it to run. Powered everything up it was being twitchy and weird, but it would move some under it's own power. Sometimes. I figured the ESC needed to be calibrated. Started to calibrate the ESC when I found one of the three tiny wires going from the ESC to the motor had broke. Last night I resoldered the wire and plugged everything back in. Powered it up and calibrated the ESC. Then tried to run it. Nothing but a little twitch from the motor. I unbolted the motor thinking maybe something was binding. Still nothing but a few twitches from the motor. I can hear the slight whine from the ESC when I pull the trigger, but that's about it. ESC runs steering servo with no issues

Is there any way of using a multi meter to check the ESC and the motor? Nothing smells funky or burnt. So I'm trying to figure out my next step of diagnosing for this issue. Any and all advice is much appreciated. Thank you in advance for any help, knowledge or direction!
 
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Honestly I'm not sure. It has 3 wires from the esc to the motor, but right before they get to the motor they go into one casing. Here's a couple pics of it before I fixed the wire that broke.
a6cd5e0263a647e2ee6f0fc703949c14.jpg

784f4e7d00b5b65eb8140f2297f8017a.jpg
 
Not familiar with this type of motor so this is all guess work but it might help.

It's a sensor less motor. Are the wires marked a b c at all? Make sure they are correct. Possibly try a different esc if you have one.
I am pretty sure 2 of those wire can be reversed, but I don't think all 3 can be mixed up. So one of them needs to be correct. The other 2 if swapped just make it go backwards.

What if you help the motor to start turning by hand, does that help?
 
Not familiar with this type of motor so this is all guess work but it might help.

It's a sensor less motor. Are the wires marked a b c at all? Make sure they are correct. Possibly try a different esc if you have one.
I am pretty sure 2 of those wire can be reversed, but I don't think all 3 can be mixed up. So one of them needs to be correct. The other 2 if swapped just make it go backwards.

What if you help the motor to start turning by hand, does that help?


There is no wrong way to wire the motor. If it spins backwards, you swap any 2 wires and it reverses the direction.
 
The motor wires on the motor appear to be the windings of the motor extending over to the ESC wires. They can be tricky to solder to because they have an enamel coating on them. You have to sand the tips of the wires to be able to get a good solder joint.

The most common failure for an ESC is that one of the 6 MOSFETs is shorted. The way to test for this with a multimeter is to put it in continuity test mode(beeps when you touch the probes together). Touch one probe to the + power wire and then touch each of the motor wires with the other probe. If any of them beep then you know one of the MOSFETs is shorted to the + power wire. Move the first probe to the - power wire and check the 3 wires again to see if any of the lowside MOSFETs are shorted. If any of the 6 tests make the multimeter beep then the ESC is dead.
 
Thank you for all the advice and help guys. I got it going! Got home from work and was able to sneak in the garage for 10 mins. It was a bad solder joint on one of the other connections. I cut all the heat shrink off the connectors to find it. Couldn't tell till then. Super stoked! Now time to deal with those tiny motor screws. Maybe it'll hit some rocks before the night's over. Thank you again everyone for your responses! Have a great evening!
 
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