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› ERaptor50 Dies middle of flying
12-10-2004 03:23 PM  13 years agoPost 1
Martevuo

rrNovice

Finland

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Why my E- raptor50 ”dies” when doing 540?
I thinks this might be a hard bite to anyone to resolve.

Story goes like this..

Setup:

Hacker B50-15XL
Gear 17:1 (Box unit 8,5:1 + 2:1)
Hacker 48-3p-opto
ff9+149DP
401+9254
24 cell sanyo2400

To day we went flying and I had in my mind this ”failsafe” problem. So I put this just peaked sanyo packs in and hovered R50. Power was ok. Kind a lazy but hey, what can you assume from heavy heli. Rpm in hover 1400 and idle 1550. Yes I know its kind low but it can be risen. (20A= 1500rpm)

This is my first fly whit new receiver. Older was also pcm but not a dual. The problem is that when Im doing 180´ or 540´ tail feels kind a lazy top of the climbing and then it hapens. NOT responsing anymore in anyway. This is the time when im shouting ”damn, its doing it again”. Last week I was high enough to handle this long long 2-3 sec. ”failsafe time” just after 20meter there was a signal again so I could land safely. To day I was kind a low when happened same thing.. ehh..

Ok, first flight today (peaked battery) I could notised few ”not responsing time” which last 0,5 sec or something. OR it was only lack of tail power.. but i think it wasnt that. 401+9254 should be ok.

Second flight whit cell which was not peaked. Heli was lazy and I had to use idle2 to get more blade angle.
idle1 +/- 9,5
idle2 +/- 11
Heli was so lazy that I had to ride foreward long time to get enough speed to do 540´. Full throttle allthe time and the pulling. Heli climbed very slow and nose pointing sky. This is the time for hopeing ..
Full rudder left-> it turned something like 90´+ decrees and stopped. Now its on its side and coming very fast down.. Crash! Big one..

This is what we have tried. We have no more ideas.

*low/high rpm
*differnet crystals
*different receivers
*different cells
*ball bearings are ok
*ESC+gyro+ receiver far form eachother
-ESC (bottom)
- gyro behind main shaft
- receiver top of the nose

This ”failsafe thing hapends only when Im putting my heli in hard plase like pulling hard and doing 540. Not in normal flight. This problems occures especially then when there is no more power in main battery to do big loops and stall spins..
I have this main battery for Hacker and 1800mahcells for servos. We just cant find any ideas to resolve this case.

Can you please help..

-joni

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12-10-2004 05:06 PM  13 years agoPost 2
BigChopper

rrKey Veteran

Cambridge, UK

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I do not have an electric heli, but I am an electronics engineer and have a lot of experience in dealing with RF interference..

From the info you supply, it looks like your motor/controller etc are injecting in-band noise into your receiver.

As the battery voltage reduces and the heli demands power, the noise generating characteristics (i.e. current spikes) will change, which is why you may be noticing this happening at low battery levels.

I would consider re-routing some of your electrics and in particular making sure that the high current supplies are as far away from the receiver as possible (including the antenna). I know you have moved the units themselves, but what about the high current wires crossing the RX supply/servo wires?

This is probably common sense to you, but no-one has replied yet, so I thought I'd throw in my opinion. Sorry if I'm 'teaching grandma to suck eggs'.

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12-11-2004 04:19 PM  13 years agoPost 3
brancoli

rrNovice

Hong kong

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may it be a Esc cut-off, if your pull out is > the esc rating?

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12-11-2004 08:51 PM  13 years agoPost 4
NZ_Neil

rrVeteran

Auckland, New Zealand

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Try running a seperate Avionics power source like the UBEC. I have no faith in ESC's with built in BEC's on Helis. The specs are just too close the maximums.for the number of servos (escpecially digitals)

Is it the BEC overloading and cutting out for x Seconds ???

Secondly when the ESC decides to go "Pop" (And they do from time to time) they will often take the BEC section out as well. Better to keep the 5v rail to the electronics completeley seperate so at least you can attempt an Auto

I am running the Hacker C50 15XL motor with :
Master 77-O Heli Esc and the UBEC with no problems on a boxed eRaptor.

Regards
Neil Harker
New Zealand

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12-13-2004 08:16 AM  13 years agoPost 5
Martevuo

rrNovice

Finland

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BigChopper : Hmm

Sounds like very unknown problem to me. But it might be right answer..
This kinks of problems are so hard to solve especially when useing pcm receiver. Wires are as far as the can from every "dangerous place"

If im thinking really hard. This failsafe-mode occures only after useing tail servo and its digital. Others are normal. Do you think this might have hands on this problem?


NZ_Neil & brancoli


My esc is opto, so there isnt any business between receiver batery and main rotor battery. both are individual. When I torment my 28cell pack by pulling 40+ amps it shouldnt affect to servos.

Thanks alot guys!

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12-14-2004 01:09 PM  13 years agoPost 6
BigChopper

rrKey Veteran

Cambridge, UK

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If im thinking really hard. This failsafe-mode occures only after useing tail servo and its digital. Others are normal. Do you think this might have hands on this problem?
Mmmm, I suppose it is possible that the digital servo is causing noise?

This is a tricky one.. I'm afraid I don't really have any experience on E-heli's to know much - I was just looking at it from a general electronics engineering perspective

If you find the cause, please do tell.

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10-07-2006 06:02 PM  11 years agoPost 7
rtdillon

rrApprentice

Huntsville, AL

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Just a thought

The Digital servos are hungry devices. If the batteries are on the low edge, could driving the tail servo hard force the gyro into reset?

I'd try putting the RX on a separate receiver battery. It may not be the final answer but the batteries are easy to comy by and it would answer questions about voltage to the RX/Gyro quickly.

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10-08-2006 02:09 PM  11 years agoPost 8
PJRono

rrKey Veteran

Minnesota, Ya!

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I agree with both these guys, use a seperate Rx supply either a UBEC or small 2S lipo with regulator. You have 3 full size servos working all the time plus a gyro w/digital servo that can draw alot of juice. Just out of curosity, is your tail servo binding at full throw? That would shut down your BEC for sure.

If you skip me I can't play!

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11-17-2006 05:52 PM  11 years agoPost 9
gtarling

rrNovice

London

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Chaps - I know you're all trying to be helpful to Joni, but the way I read his post, he's already using an 1800mAh receiver battery. Joni - let us know if this is the case or not and we'll try to suggest other things to try. To me, it sounds as if your PCM receiver is locking up for some reason - probably interference. Try doing some careful tests with a non-PCM receiver to see if you're getting any glitching.

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11-19-2006 10:18 PM  11 years agoPost 10
PJRono

rrKey Veteran

Minnesota, Ya!

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OK with a headspeed of 1450 your tail isn't going to have much if any power in a raptor(I have done it for giggles). I wouldn't even think of putting it in a stall turn with that headspeed. Are you using larger tail blades(to keep tail authority)and/or main blades? At 1500rpm mine felt like mush. Otherwise if you threw the rudder full over and it bound(limits weren't set right) she might have locked the Rx up. Also where does your antenna sit on the heli? Any E-heli is prone to more glitching than a glow. Are you running a ferrite ring on the ESC Rx lead? Also with a 48amp controller and drawing 20+ amps @ hover I'm thinking your load on the ESC might have shut it down when going back to + pitch(most of use know the Hacker ESCs aren't that great for helis). What do your throttle curves look like, are you using a governor? There's lot's of grey here!!!!

If you skip me I can't play!

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