PlaneHeli

Gidday,

I would like to set the Idle on my Caliber 30 (Futaba CHP7) to operate with a switch.

At start my throttle / pitch stick is set full down and the trim set to central.
Before takeoff I increase to trim to max up. But with these fancy electronic sets rather than the old radios, its a little more cumbersome (holding the trim switch and waiting for it to slowly increase, particularly when setting up and having to do it many times)

What I would like to do is use a switch to increase the idle from starting idle to flight idle.

It seems the idle up settings involve pitch and throttle curves.

Should I do this
Whats the best way to do this.

Do you increase the pitch / throttle trim to max before fight, or do you just use the throttle stick. If you just use the throttle stick wouldnt the revs get a bit low if you throttled right back in flight.

Cheers Cal83

Gorgok

I use throttle hold as idle. Flip a switch and its in idle, flip it off and the curve takes over. Its a good idea not to jump to full throttle from idle... so flip off throttle hold in a low throttle position.

PlaneHeli

Thanks Gorgok

So you start the engine with throttle hold ON to give a low idle for starting. Then switch throttle hold OFF to bring up the revs slightly before taking off.

I assume you mean with throttle hold OFF and the revs higher, you have set it up so the Heli is still sitting on the ground and requires throttle stick forward to liftoff, --- it doesnt rev high enough to liftoff into a hover without moving the throttle stick.

Cheers Cal83

Gorgok

I have throttle hold as low as the engine will idle at (for enough time for me to do what i need to). When its ON, it will idle no matter what. I have 2 flight modes, 1 is non inverted, straight throttle curve, low stick being around 20% throttle (it will spin the rotor, but too slow to fly). Flight mode 2 is a V curve.

To start flying.

Flip TH ON.
Start heli.
Get ready.
Make sure throttle stick is low.
Set Flight Mode 1.
Flip TH OFF.
Throttle up to gain headspeed.
Past mid stick headspeed should be full.
Hover at around 3/4 stick.

Anywhere past mid stick i can flip to Flight Mode 2 (without a jump); in the air or on the ground.

PlaneHeli

Thanks Gorgok

Ive set my heli up as you suggeseted. throttle hold on for start, Off for flight idle.

Works well.

Must be careful to ensure Th Hold on for start though, otherwise will start with revs too high.

Cheers Cal 83

Gorgok

Yeah, without throttle hold on, i do not think my heli would start... Even though its low throttle in flight mode 1, its much too high to start (safely at least, if at all).

BarracudaHockey

My Feedback: (11)

Oh it'll start. Then it will grind your clutch to dust. Don't ask me how I know.

Always hold the head firmly while starting or it will get even more exciting than watching the black cloud that used to be your clutch liner float away.

PlaneHeli

Barracuda

Agreed,

Are there any better ways of doing it.

Or does everyone else stick with the trim method. Mid trim for start and high trim to spin the blades up for flight.

The old trims would be better for this, these new spring loaded trims you have to hold and wait are a step backwards imho.

Cheers Cal83

fritzthecat

My Feedback: (4)

My engine idles at below the clutch engagement point. Throttle Hold it idles just a tiny bit higher but still doesn't engage the clutch. There is no reason to use a Flight Idle. The only times the engine should go to idle in flight is in Throttle Hold and in Normal Flight Mode with the stick all the way down. All other regimes are controlled through the throttle curve. The only time I touch the trim is on the first start of the day when I give it 5 clicks up to facilitate easier starting. Once it warms up I click 5 down to get back to the std idle speed.

Fritz

BarracudaHockey

My Feedback: (11)

Yep what Fritz said. Just set a reliable idle then use the throttle stick to advance the throttle and engage the blades. When you are ready and use idle up once you get the blades spun up it will be a non issue anyways.

PlaneHeli

Fritz & Barracuda,

Thanks for your advise.

So you both agree there is no need to use trim or a switch to increase rpm to spin the blades up before using the throttle stick.

I wasnt sure if this would cause problems in flight if you were to bring the stick back too far in flight. i guess that shouldnt happen unless you intentionally pull the stick right back if it going to crash. This would lower the rpm and disengage the clutch prior to impact which would be better.

I will reset my Heli to do this.

One question though. Why do people set up a throttle hold to practice autos if you could just bring the stick right back. Or is the throttle hold normally set higher than the stick back at idle.

Cheers Cal83

Gorgok

Because if you do that you will have whatever pitch you have at bottom stick, and fall like a rock. Once you want to stop falling, giving more collective will throttle up the engine too. Which kind of makes it no longer a auto at all..

I keep my normal mode bottom stick higher than idle and spinning the blades (slowly), i'd rather not risk killing the engine (in a idle) if i have to throw the stick all the way down. Thats why i use throttle hold for idle. Also, its very simple to idle at any time very safely, and still have full collective control if i want. And of course i can practice autos.

PlaneHeli

Gorgok,

Of course, throttle hold holds the throttle while you still have full collective. Thats a real Auto (except the engine is low idling rather than stopped).

Your comment of using throttle hold JUST Slightly to stop a flame-out is fair comment too, If its idling low enough not to spin the blades it is a fairly low idle and more likely to flame-out.

Ive just tried my heli with no flight idle, just using the throttle/pitch lever, but when you throttle back in flight, (even not completely, it drops very fast)( do most of you just set the throttle curve to 0,25,50,75,100.

Id be interested to hear from other experienced Heli guys what your prefered settings are.

1
Start at idle and just use the throttle/pitch lever to increase revs.

OR

2
Start at idle then using some method (trim or switch) increase the idle rpm for flight, so you dont throttle all the way back to the low starting idle any time during flight.

What does everyone recommend.

Cheers Cal83

BarracudaHockey

My Feedback: (11)

If you are to the point where you are flying around and throttling back in flight to descend you should probably be using idle up so that you don't loose head speed.

Gorgok

Yeah i should start using my other flight mode (idle up i guess) more, right now im still using normal mode.

For my throttle curve... i have normal mode 0, 26, 52. (For a pitch curve of -3, 0, 10) My Toki .40 in the Hawk Pro can even take full collective at about half throttle... I have no idea of the headspeed, but it sounds and flies OK.

My throttle hold is at -6, lower than normal mode lets me go.

Idle Up curve then is 52, 26, 52. (-10, 0, 10 degrees of pitch)