450 450 Help required

[Graham Lawrie]

Hi Guys, I fitted new rotor link arms to my 450 today and started going through the 3gx setup and blade pitch etc, thought i was finished put my training gear on and went out to fly.

It was as if the heli was in reverse(negative pitch) as i spooled up she pulled down and i could seethe training gear bend ground wards. I guess i have done something wrong in the 3gx set up , but not sure what.

At centre stick all is level, but when i bring the left stick down servos are staying at 90 , no downward movement. I must have reversed something or not done something right in the set up.

NEW DEVELOPMENT:

I have fitted a new battery and now the servos are hardly moving at all? I started to do the 3gx set up and the only servo working is the tail?? confused dot com?

 

[Westy]

Try to RE bind the RX and go through the complete setup of the 3gx again.

Just a suggestion

 

[Tony]

This sounds more like a pitch curve issue with the negative pitch issue. What is your normal, idle up and throttle hold curves set to? As stated, I would rebind the Tx to the Rx and try the setup again.

 

[Graham Lawrie]

Try to RE bind the RX and go through the complete setup of the 3gx again.

Just a suggestion

Well that was the end of an epic night

I did just as you said Westy as no one replied, i did just that, rebound and went through the full set up, and it all worked Then what followed nearly reduced me to tears!!

All finished and ready to fly tomorrow, i switched off the TX, then went to disconnect the battery. Instantly the heli started to spool up I managed to avoid the worst, but the blade struck my arm right where my tennis elbow is killing me, i grabbed the tail boom and lifted it onto the floor with the TX, which in my haste i had hit a switch so when i switched it on it bleeped . Given the speed now of the rotor , holding the tail rotor to keep it in place, i pulled the plug one handed off the battery, during which the rotor striking my arm must have slackened the pinion from the motor.

No damage, just a very bruised ego.

I then had to strip down the heli to reset the pinion, and re-build. Now complete and ready to fly.

Not sure why it was playing up in the first place, but the re-bind and a new model set up on TX seemed to work.

 

[heli-maniac]

thats why never ever turn off the TX first always unplug the battery first
but good thing no major injuries or damage was done
i unplug the motor wires wile doing any set ups

 

[Tony]

As stated, you if your heli is plugged in, you should always have the Tx on. That keeps it from catching a glitch and doing just what it did. I learned this the hard way back in the 72mHZ days.

 

[Westy]

yep ... what he said .... or ..... alternatively .... ALWAYS take the Main an tail blades off or disconnect the motor or run a separate bat and servos so the ESC is not running only the Rx and servos.

I got taken out by the blades once when I first started ... took weeks for the bruising to go down on the 450 .... imagine the carnage if it was the 600 ..... Neva ... .eva .... turn off the TX first . I guess you lesson is well learned . i hope your elbow heals soon to get back into it...


I am glad your problem was solved though ... wehn you mentioned a battery change ... I thought there may have been a software issue when you disconnected.

 

[Graham Lawrie]

I hear you all guys When i had my coaxials i always did it TX first, but i read somewhere that you did it the other way round. Lesson learnt. I have been doing it this way for some time and this is the first time that it has started up It hit a lamp shade on a desk top lamp i have and hurt my already sore arm with tennis elbow(that is like toothache) so worse than normal so poor nights sleep for me.

ONWARD AND UPWARDS:0

 

[Lee]

If it spooled up when you turn the TX off, then your fail safe is set wrong. Did you have the throttle stick at 0 when binding. You should have all switches and sticks in the position you want the heli to see if it looses contact with the radio.

 

[Graham Lawrie]

Ah, penny dropped, i would have been at mid stick

 

[John Baloo]

Lee when say 0 do mean at centre stick position ?
John

 

[Lee]

Hi John
No it should be at low stick, so if the radio signal is lost, Receiver will send a 0 throttle signal to the heli and cut the motor.

 

[Westy]

Hi John
No it should be at low stick, so if the radio signal is lost, Receiver will send a 0 throttle signal to the heli and cut the motor.

This will allow the heli to sink from the skys .... and hopefully back into non brown out range. You can set it higher (throttle position add pitch also) but the more pitch you pull by adding throttle.... the more the head speed is reduced.... and after not too long ... you will have a falling electronic rock with a stalled head! Haha.

 

[Tony]

This is one of the reasons I suggest the pitch curve of 45 47.5 50 75 100. At low stick, you will have about -2º of pitch that will keep that head spinning and keep the tail spinning. Much more likely for it to have a hard upright landing rather than falling like a duck that just got shot. It's amazing just how stable an uncontrolled auto rotation can be.