Loss of Power

nick_onelove · Posted: Mon Aug 29, 2011 3:44 am Post subject: Loss of Power

I went to fly my FBL Trex 450 Pro today and for some reason it's like it isn't getting enough power. Even at 100% throttle and full pitch it only only hovers like 6 inches off the ground.

The heli has never been in a crash and was flying fine a couple days ago. It has an almost brand new Align "Super Power" motor.

The one-way bearing on the other hand is the same one it has had since it was built. Could that be causing the rotors to not turn as fast as the motor is turning the gear? Or does this sound like a motor problem?
_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

Scott · Extreme 3D Joined: 11 Nov 2010 Posts: 340

Sounds like a battery problem
These brushless motors are pretty much
trouble-free.My guess is the fuel tank.

T-R-E-V · Posted: Mon Aug 29, 2011 5:13 am Post subject:

New motor you may be you need to re-program your ESC, through a series of bleeps, and throttle positions. Idea

Trev.
_________________
3 Ch Mini Tracer Infrared Helicopter
3 Channel Alloy Shark S006
4 Channel E-flite Blade CX2
6 Channel E-Sky Honey Bee King III
6 Channel HK-250GT
6 Channel T-Rex 250
3 Channel T-34 Series RC Helicopter
6 Channel Storm 450 RTF

solentlife · Posted: Mon Aug 29, 2011 3:20 pm Post subject:

I've had my ESC go of program and need to reset throttle on both my helis and fixed wing jobbies. I put it down to spikes or glitches that may pass when coupling up battery to ESC - especially when you quickly unplug again before ESC has completed start0up cycle. My theory anyway.

Of course other is tired battery. We all love to see our LiPo's go on and on and on and on ......... but if you are a "frequent flyer" .... that life can be pretty short ... and shorter if you fast charge your LiPo's. I'm a great believer in charging at C or lower rate to try and preserve my pack life. Given the hard life we give them powering up those motors - a bit of kindness is worth it I reckon.

Final possible ? Maybe motors bearings are worn ? Cable connectors been pulled / damaged and resistance is higher preventing full power ? Gear mesh or tail drive too tight and causing binding ?

I'm sure you've looked at all the things that you have tinkered with since last flight ? What's been changed, altered, replaced ?

Me - I'm waiting for weather to improve so I can go out and fly !!
_________________
If you don't crash - you ain't flying !
Fast learning to be 450 Heli Repair specialist !
Have : 2ch Bumblebee,
Co-Ax Syma S006 Alloy Shark
2x Clone 450 SE V2
+ fixed wing stuff ...
Returning to RC after 20 odd yrs away .. Ex Display flyer.

nick_onelove · Posted: Mon Aug 29, 2011 11:36 pm Post subject:

OK, I tried a different, newer battery to no effect. The motor pinion doesn't seem to be slipping either.

I'm having a hard time suspecting the motor or ESC because the motor sounds like it gets louder as I increase the throttle, it's just like the head-speed plateaus at around 50%. Should I order up a new one-way bearing?
_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

solentlife · Posted: Mon Aug 29, 2011 11:49 pm Post subject:

OK ...

One-way bearing check : Holding heli on its side and facing left, skids to you, blades away and free to rotate in front of legs.
With left hand place thumb on top main gear wheel and stop it rotating.
With right hand thumb turn lower autorotate gear to left - it should turn freely. Now try turn to right - it should lock and want to turn main as well. The locking should be within a couple of degrees.

Have you tried tacho-ing the head to see what head-speed you have ? I use a LED opto tacho - cannot afford the one usually quoted where you view the heli in flight !! Mine has a small piece of reflective tape on a flybar paddle and you aim LED red light at it ...
Done with negative pitch on - heli will stay on ground ... I only run it up to usual hover speed and no more.

To be honest I've never heard of the one-way bearing slipping ... shearing of yes - I've had 2 break.
_________________
If you don't crash - you ain't flying !
Fast learning to be 450 Heli Repair specialist !
Have : 2ch Bumblebee,
Co-Ax Syma S006 Alloy Shark
2x Clone 450 SE V2
+ fixed wing stuff ...
Returning to RC after 20 odd yrs away .. Ex Display flyer.

nick_onelove · Posted: Tue Aug 30, 2011 12:17 am Post subject:

It seems fine in my hands; it locks when I try to turn it backwards and it takes a fair amount of strength to force it. Is it possible it's slipping at higher RPMs though?

I'm planning on getting a nitro heli soon anyway, so I guess I'll go ahead and order a tachometer now. Like I said though, I can tell just from the sound that the head-speed isn't high enough. What's confusing is that on the other hand the motor sounds fine.
_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

solentlife · Posted: Tue Aug 30, 2011 12:55 am Post subject:

DON'T force the oen-way bearing to slip !! It's a very clever mechanism based on unidirectional friction ! Forcing it to slip could destroy the locking properties.

If the one-way is locking as it should - then I'm starting to think you have binding somewhere ..... maybe dirt / crud has got into bearings and now they are dragging ... bringing the shaft speed down. I stopped flying of grass because I was getting build up of grass 'cuttings' in the tail shaft ...

Do you oil your bearings at all ? Do you occasionally lift out head and clean up / lubricate the bearings ? I use common 3-in-1 oil as sold for bicycle use ... toothpick to dab little drop here and there ... keeps it all going nice.
_________________
If you don't crash - you ain't flying !
Fast learning to be 450 Heli Repair specialist !
Have : 2ch Bumblebee,
Co-Ax Syma S006 Alloy Shark
2x Clone 450 SE V2
+ fixed wing stuff ...
Returning to RC after 20 odd yrs away .. Ex Display flyer.

nick_onelove · Posted: Tue Aug 30, 2011 5:29 am Post subject:

No debris. I haven't oiled/lubricated anything yet, but this heli also hasn't been flown all that much yet.

On a whim I re-programmed the ESC and it actually seemed to help a tiny bit, I can actually cruise around now but it requires full pitch to climb very slowly. Even stranger, when I goose the throttle/pitch the tail blows out like a crappy motor-driven tail!
_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

nick_onelove · Posted: Tue Aug 30, 2011 8:01 am Post subject:

Well I feel like an utter idiot. I went to calculate what my head-speed should be online and I noticed the new motor is only 1700Kv; it's meant for a 6S battery setup . . . Mad

I'll be ordering the proper 3400Kv motor for 3S setups tomorrow . . .

Thanks for all the help, sorry to waste your guys' time with a pure oversight on my part. Embarassed

_________________
Align: Trex 250 3GX + Trex 450 Pro with Vbar
Blade: 450 X, mCP X, 120 SR, mSR X, CX3, mCX2
Esky: Belt-CP X and V2 - Futaba: Heli-Max Axe 400
Walkera: V500D01, M120D01, V100D08, DEVO 8
Spektrum: DX8 - AMA #967873 - IRCHA #4095

T-R-E-V · Posted: Tue Aug 30, 2011 1:19 pm Post subject:

Hi nick_onelove, congratulations in finding the problem. You’re not as daft as you thought you was by doing a head speed calculation, Wink

you are not wasting anybody’s time we are here because we want to be here, again learning from mistakes’ can come in all shapes and sizes.

Don’t forget to program the ESC back when you have the 3400kv motor fitted. Idea

Trev.
_________________
3 Ch Mini Tracer Infrared Helicopter
3 Channel Alloy Shark S006
4 Channel E-flite Blade CX2
6 Channel E-Sky Honey Bee King III
6 Channel HK-250GT
6 Channel T-Rex 250
3 Channel T-34 Series RC Helicopter
6 Channel Storm 450 RTF

solentlife · Posted: Tue Aug 30, 2011 3:44 pm Post subject:

T-R-E-V · Posted: Tue Aug 30, 2011 6:42 pm Post subject:

Hi solentlife I would not say this was a confession,

More of recognition to your fault finding skills, that many others may benefit from if they find themselves in a similar situation.

Trev.
_________________
3 Ch Mini Tracer Infrared Helicopter
3 Channel Alloy Shark S006
4 Channel E-flite Blade CX2
6 Channel E-Sky Honey Bee King III
6 Channel HK-250GT
6 Channel T-Rex 250
3 Channel T-34 Series RC Helicopter
6 Channel Storm 450 RTF

solentlife · Posted: Tue Aug 30, 2011 7:00 pm Post subject: