R.I.P. Compass motor

[Coco66]

My loyal Compass 1320kV abandoned me after 266 flights.

I was approaching for landing, and lost motor power all of a sudden.
Dropped in the grass from 3m height so nothing else happened.
Got the heli, tried to spool up, the can spools but nithing else turns.
Pulled up the can just a bit, voila', shaft broke just out of the motor.



What new motor should I get?

I run a 17T pinion and was doing 3 minutes at 3400 RPM governed, with YGE 90LV and Gens Ace 1400mAh.


.

[Scream]

Mine went recently too and I decided to treat myself to the scorpion motor with the 4mm shaft, using the 17T also and compared to the stock its been a nice improvement for me!

I was running the 16t on the stock though but with 1300s getting 4mins of mild 3d on the stock and 3:30 on the new scorpion using hw50a v3 governor store mode.

[Coco66]

FWIW, I found the reason: motor mount was bent, from some previous crash (unnoticed of course), so the motor was working at a funny angle and shaft slowly broke.

[Luigi_tuga]

Nice find
I thought about a bad alignment between motor mount and third bearing. With everything well setup, this should never happen, and the third bearing adds huge longevity to motor bearings.
You may change the shaft only, stock motor is very good.

[Coco66]

Originally Posted by Luigi_tuga

You may change the shaft only, stock motor is very good.

That's an intersting idea... how would you do that?
Where to source the shaft?
Which tools needed for cutting it?
How is the shaft attached to the can, actually?

Never tinkered with motors...

[Raz0rSh4rp]

When mine broke Prostar sent me a new can with the shaft attached. They said trying to change the shaft was too much of a pain.

[Coco66]

Wow, I just realized I have another Compass motor in the parts bin.
Don't remember why I changed it, but the old one is marked as "broken".
At least I will for sure be able to reuse the shaft or shaft/can!

How do you remove the shaft?

There is a sort of collar down where the shaft goes out (it has been lost in my broken one), and a set screw on the top.

Never tinkered with motors... what's the procedure?

[Coco66]

Done!

You guys saved me 70 EUR!!

I found the original instructions from Compass when they sent around new cans for the ones who had the funny noisy ones (1st batch I think).

So I realized the collar is only a press fit, so I could easily get it out and have a nice can/shaft assembly. Installed that on the current motor, easy peasy.

Now I just need to buy a new motor mount.

I love HF!!

[Coco66]

Double post

[Luigi_tuga]

Compass sells only the shaft, nice to get when you change bearings, new bearings/shaft and everything gets as tight as new :-)

[Coco66]

Originally Posted by Luigi_tuga

Compass sells only the shaft, nice to get when you change bearings, new bearings/shaft and everything gets as tight as new :-)

Good for next time then... talk about it again after some more 200 flights )))))

Always wanted to ask you: do you have Italian roots? Why Luigi and not Luis?

[Luigi_tuga]

It should last ages if everything is well set. Mine is still the same from day one after several thousands flights (shaft came with the upgraded can).
Having the third support perfectly aligned is a must. I do this with the motor spinning, and tighten very gently the 4 bolts from the third bearing support to don't induce any twist (in a cross pattern), then retighten them to the nomal torque.

Regarding to my nick, Luigi is the nick i had when younger, and i addopted it to the forums. I'm Luis , but i was Louis a long time ago, I'm French