Stock Batbone motors really hot

[happyman88]

I am running an almost stock batbone tricopter the only changes are the escs to 30 amp ( just what was in stock at the time) and 8 4.5 props instead of the recommended 8 4 props. (again what was in stock at the time). after flying for a few minutes the motors will get hot to the touch, sometimes to hot to touch. I have checked for any binding or anything and there is none. The escs are warm but nothing out of the ordinary. I do not now what to do at this point, should i be worried about the motors? or is this normal?

 

[Craftydan]

Happy,

one thing you skipped over . . . what motors are you using? Also what size battery?

BTW, warm is OK, Hot is not.

 

[Foam Addict]

I am running an almost stock batbone tricopter the only changes are the escs to 30 amp ( just what was in stock at the time) and 8 4.5 props instead of the recommended 8 4 props. (again what was in stock at the time). after flying for a few minutes the motors will get hot to the touch, sometimes to hot to touch. I have checked for any binding or anything and there is none. The escs are warm but nothing out of the ordinary. I do not now what to do at this point, should i be worried about the motors? or is this normal?

Also, what battery?

I'm assuming you are top using the blue wonder, did you get a higher KV version?

The 1500 KV version can only handle about a 7x3.5 prop on 3s.

 

[happyman88]

i am using these motors :http://www.hobbyking.com/hobbyking/store/__14398__turnigy_park300_brushless_outrunner_1380kv.html and i am using either a 2200mah 3s or 3000mah 3s. The motors themselves are hot the escs are warm but not at all hot or burnign to the touch like the motors.

 

[Foam Addict]

Ah, those are way over propped. The 8x3.8 prop is for 2 cells, not 3. If the motors aren't to badly damaged, some GWS 7x3.5 props MIGHT work, but I think you might want some 2826 1400 KV motors.

 

[happyman88]

the motors you recommended are a higher kv then the ones im using already how would that help the problem and this is very close to the batbone recommendations on the site, so why would it be recommending an over propped setup?

 

[Craftydan]

Notice the difference in the "max current" rating -- the motor FA recommended can handle 3 times the current than the one you have. that means it'll be able to work harder turning a bigger prop without wasting energy as heat . . . which has a bad habit of melting insulation and turning a perfectly good motor into a smoke machine . . . briefly.

As for why FT *STILL* has those motors up for a recommendation, I don't know. they're not well suited for multirotors for more than one reason.

 

[happyman88]

is there a semi easy and cheap fix at least for a little while as i do not have the budget to buy new motors?

 

[Craftydan]

Yeah, the bid downside of multirotors is what you only need one of on fixed wing you now need multiples, and multiples of the cost and setup

As FA suggested, shorter props. you'll probably be fine with a 7x4-ish prop. Either buy a new set (easy) or *CAREFULLY* trim a 1/2" off the props you already have (cheap, but complicated) -- you'll want to make sure the cuts are equal and the props are balanced afterwards. I've seen people build cutting jigs to ensure the prop gets cut at the same diameter, and they're not hard to build, but it'll depend on the tools you have at hand.

Now how well these motors will work? The batbone frame is kinda on the big side for these motors, but it should get you in the air.

 

[Foam Addict]

Yeah, the bid downside of multirotors is what you only need one of on fixed wing you now need multiples, and multiples of the cost and setup

Yeah that is a major downer...

 

[happyman88]

Triming props is not a problem cause i have lots of extras, so would it be 1/2 of both sides of the prop or 1/4 of each side?

 

[Craftydan]

1/2" on each side for a total of 1"

 

[happyman88]

alright ill do that today and see if it cools down the motors.

 

[happyman88]

So that fixed the front 2 motors but the back tail motor is still getting fairly hot, not as hot as before but still enough that it cant be touched for more than 4 sec without pain.

 

[Tritium]

Your back motor may have suffered some shorting of windings due to the previous overload. Does the motor wire insulation look darkened?

Thurmond

 

[Cyberdactyl]

Also if the multirotor's CG is way off. . . (more than 50mm from where it should be for your size craft) it can make the motors closest to that CG run hotter.

 

[happyman88]

there is no damage to the motor that i can see i barely even ran one battery through them before i came here. how would i go about checking cg on the batbone

 

[Tritium]

Roughly CG should be center of flite controller. Thurmond