From turn the Tx on, to take off....

[aaronb]

Ok so, this probably should go in "Beginners Questions". But as the last post in there was back in November, I figure its not going to get looked at. So, you are all pro's and know what you're doing     I thought I'd come straight here.

Here's my problem.

I've now got all the kit needed for CP flight. I've got my Heli Tx and Neil (P's) old HB Elite   (How lucky am I). But never having seen anything in person I'm finding it tricky to get my head around the whole 'Throttle and pitch' on one stick thing.

There are a tone on words in the Heli Tx manual and a book I now have, but unless I know what they means, it may as well be trying to figure out what happens when you hover a heli in a truck.

So. If somebody could BRIEFLY explain what the procedure is from start to finish - Turn on Tx, plug lipo into ESC.... - I think I could get it.

Does this make sense? I basically dont know how it works.
DO YOU (once lipo plugging in): throttle up with throttle stick, then flick a switch keeping the throttle at those RPM??? then move the throttle stick down to centre or bottom, then flick same / another switch to then use for pitch???????????
       I just dont get it.

[davidcollins001]

http://www.heliguy.com/nexus/programming.html
http://www.aerohobbies.com/

These might help you a bit

[Sao]

Pitch and throttle are on the same stick and the mixing is taken care of in the Tx by throttle and pitch curves, you can then select different flight modes or stunt modes or idle ups (manufacturer specific names)

On MY helis they are all set up the same.

Pitch curve from 0 to 50 to 100% LINEAR
Throttle curves set up for governor mode.

Examples

Norm Mode
Pitch curve 45% (to reduce the amoutn of neagtive at bottom stick when spooling up) 50% 100%
Throttle curve 0% (so i can plug it in without arming the Esc) then 50% 50% for a lower headspeed for hovering

Stunt curves or idle ups
Pitch curve 0 50 100 (this gives symetrical amounts of ptich with 0 Degrees being at midstick
Throttle curve (for governor mode) 80 80 80 this gives me a nice highheadspeed for acro.

In practice
I Turn on Tx and hit throttle hold/cut, plug in Lipo, hear arming noise from Esc, walk back, put throttle/pitch stick to mid point IE 0 Deg of pitch, select idle up then take off throttle hold, heli spools up to headspeed with pitch at 0 so it doesnt tip over get pushed into floor or leap up of ground. Lift off and fly

Does that help a bit? I can write a more detailed version if you want

[aaronb]

Yeah thats the kind of thing.

So, when you take of throttle hold the motor will spin to the preset level? You don't have use the throttle stick to go from 0 to full revs?

[Sao]

aaronb @ Thu May 05, 2005 1:07 pm wrote:

Yeah thats the kind of thing.

So, when you take of throttle hold the motor will spin to the preset level? You don't have use the throttle stick to go from 0 to full revs?

Correct, as soon as i take off throttle hold the Esc sees 80% and spins up to that speed, then when i change the amount of pitch the governor mode of the Esc keeps the headspeed constant (well in theory but I am finding that governors lag a bit during extreme manouvers) If your Esc does not have a governor mode than you will need to program a suitable curve to keep you headspeed constant.

Throttle curve in normal mode 0 25 50 80 100 (GUESSED FIGURES!!!!)

Throttle curve in Stunt mode 100 90 80 90 100 (GUESSED FIGURES!!)
You want throttle top and bottom of the stick for flying inverted when in your stunt / idle up mode

[aaronb]

So, when you give it a load of pitch, the motor will speed up to counteract the stress its put under?!?

So for example, when your pitch is at 75% ideally your throttle should be 75% too?

Does that mean if the throttle stick is down, that will be 0% throttle and 0% pitch?

[DarkHorse]

The idea is to maintain the same rpm whatever pitch (rotor thrust) you demand.
Most people use normal flight mode to get the heli spun up and for moderate hovering about.
Then flick to idle1 (or stunt 1 mode) for a full set of curve both + and - pitch.
Look at Sao's numbers again.

> So for example, when your pitch is at 75% ideally your throttle should be 75% too?
If that gave you the required rpm you wanted then yes

> Does that mean if the throttle stick is down, that will be 0% throttle and 0% pitch?.
In normal flight mode, kind of... if you wanted full - pitch with 0 rpm. 30-40% or a bit of - pitch might be more suitable (up to pilot preference).

[XH558]

Sao @ Thu May 05, 2005 12:49 pm wrote:

In practice
I Turn on Tx and hit throttle hold/cut, plug in Lipo, hear arming noise from Esc, walk back, put throttle/pitch stick to mid point IE 0 Deg of pitch, select idle up then take off throttle hold, heli spools up to headspeed with pitch at 0 so it doesnt tip over get pushed into floor or leap up of ground. Lift off and fly

Aaron I bought Sao's Eolo and I had a hell of a job getting my head round this very thing having learned to fly on a fixed pitch where throttle equals height    
But Sao guided me in exactly the way he has explained to you and he helped me set up the TX in the way he's described and then when I spooled up the first time it suddenly hit me    
With throttle hold on the motor does not run at all and you can check all the controls work and see the pitch input sliding the swash up and down (I love the way it does that and takes all 3 servos with it equally - that is so cool   ) - then when you drop the throttle /pitch stick to zero - turn off the throttle hold and lift the stick to mid way the beast goes straight to a constant (and what seems like mindblowingly fast) headspeed - and input from then on is just pitch and the throttle compensates itself.  

Its a whole different concept but its really as simple as Sao describes it above when you get your head round it    

PS how's the relocation to Oxfordshire going? - decided where yet?

[DarkHorse]

> With throttle hold on the motor does not run
First thing to do is set this feature up. I use 'Throttle Cut' instead of 'Throttle Hold' on the Futaba 7C. Assigned to switch 'A' and 'on' when flicked down. whatever, test it!

[aaronb]

I'm really sorry guys, I am getting it. This is a huge help. Thank you.

I've got the Futaba 7C too and I checked out the setting of the previous owner. Pretty similar to what you guys have said.

What I'm stuggling with is this:

- You got throttle hold / cut on to stop the motor turning
- You can then use the throttle stick to check the pitch
this is where I'm losing it
- You take off the throttle hold/cut switch and it spools up....
- From then on is the throttle stick only for pitch? (the cogs in my head are falling into place as I'm typing this   )
- The motor will spin to whatever the stick is at because its following the pitch movements....YES / NO????? Am I there yet?

Coming from FP helis and planes, the throttle make motors go faster. I'll ask about Idle later. Let me get this first.      

[aaronb]

I'm really sorry guys, I am getting it. This is a huge help. Thank you.

I've got the Futaba 7C too and I checked out the setting of the previous owner. Pretty similar to what you guys have said.

What I'm stuggling with is this:

- You got throttle hold / cut on to stop the motor turning
- You can then use the throttle stick to check the pitch
this is where I'm losing it
- You take off the throttle hold/cut switch and it spools up....
- From then on is the throttle stick only for pitch? (the cogs in my head are falling into place as I'm typing this   )
- The motor will spin to whatever the stick is at because its following the pitch movements....YES / NO????? Am I there yet?

Coming from FP helis and planes, the throttle make motors go faster. I'll ask about Idle later. Let me get this first.      

[XH558]

XH558 @ Thu May 05, 2005 9:24 pm wrote:

 Aaron I bought Sao's Eolo and I had a hell of a job getting my head round this very thing having learned to fly on a fixed pitch where throttle equals height  

Quote:

Coming from FP helis and planes, the throttle make motors go faster. I'll ask about Idle later. Let me get this first.

Notice a similarity here   We both had/have the same issue and once you get the idea that the throttle curve sets the headspeed and then the stick gives you the pitch to lift it gets easier to grasp

Quote:

You take off the throttle hold/cut switch and it spools up....
- From then on is the throttle stick only for pitch?

That's about it as I see it with a constant say 60% from mid to end of stick movement  0 0 60 60 60   The only thing that can change that, as I understand it, is if you were to dial in say 0 0 60 75 75  - then the throttle would up the headspeed as the stick rises and more pitch comes in. But 60% seems fine on my EOLO and I don't think higher headspeeds are necessary for early practicing only for blinged out 3D stuff  I could be wrong - it has been known

[Q]

Hmmmm, I feel a bit more info is needed here.

First of all, on a collective heli you try to keep a constant head speed, no matter what the collective pitch is at. Secondly, you want to keep a brushless motor running close to 100% as it's more efficient that way.
Sooooooo,
1) You decide what head speed you want to run at
2) You use a motor pinion that allows you to run at that RPM at 80% throttle
3) You set up your normal throttel curve at 0 - 75 - 100 (changes apply to different setups)

Now here it gets a bit more difficult depending if you use governer mode on the ESC or not. With governer mode you ask the ESC to keep a constant speed, no matter what the load is. Of course it can't go over the maximum power available!! You can only set it on the ESC prior to your flight, not on the Tx.

With governer mode
4) you set your idle up at 80% flat out.

Without governer mode
4) you set a slight V like 100 - 90 - 80 - 90 - 100

These number change depending on whether you want full negative pitch or not, whether you want to hover at mid stick, or have 0 pitch at mif stick.

What I wanted to say really is : keep the throttle as high as possible and adjust the motor pinion to get the head speed to your needs. A constant 60% throttle will give you a very hot ESC and motor and a short(er) flight.

[davidcollins001]

What you should do is to try to imagine what is happening as you move the stick.

You can set the stick so that throttle goes from 0 25 50 75 100 - that is as the throttle stick is at those 5 points (bottom quater up, middle, 3/4 up top) so as the stick is moved the engine will speed up dependant on the position of the stick.

Now forget this and think of the pitch. You can also set it for 0 25 50 75 100, so the pitch will be adjusted as the throttle stick is at these 5 points again.

Now put them together, and imagine what is happening with the pitch and throttle. Then think what if I set a throttle curve like 0 80 80 80 80, what is happening to that as you move the stick - at low stick the motor is at 0%, a quarter up it is at 80% and stays like that for any stick movement above. Now consider adding in the pitch again.

Try to visualise what is actually happening with the stick, move the stick and think about what should be happening. You might find it easier to consider the throttle not as another axis, but just as something different, from now on pitch controls up/down axis, and throttle is just something different

Hope this helps a bit

[scoot]

personally I set my normal throttle curve to be 0, 90,90,90,90 when using a govenor this means I dont get any change in head speed when going into idle1.  Not sure setting it to a linear curve with a govenor is the right thing to do as Q has suggested.

[aaronb]

Cheers David, that does help.

So for a normal flight (no inverting) I should set up the Tx like this for eg:
Throttle curve 0 80 80 80 80
Pitch curve 0 25 50 75 100

That should give me a setup that is:
Stick down = no movement / flat blades
1/4 stick = 80% throttle (blades properly spinning) / 25% pitch (heli going light)
1/2 stick = still 80% / 50% pitch (heli lifting there or there abouts)?????
Anything above half with the stick is goes to increase the rate of climb????

[Q]

Scoot, a horizontal linear curve is correct in Idle up. Idle up is the way you normally fly. In my understanding you only use normal mode to spool up.
If you fly in normal mode with a 0- 90 - 90 - 90 - 90 curve, you risk shutting down the ESC when doing a full negative. As it takes the ESC a second to initialize, you won't have a change of recovering. Of course, everything depends on your flying.

With my Kontronik ESC the spool up is so smooth, I have my throttle set at 85% and just flip the throttle hold. The motor comes to life ever so smoothly. Buzz flies this way too.

[scoot]

it depends on how much pitch is on your blades at mid stick as well.  I normally set mine up to have 0* pitch at mid stick and -10 at bottom stick and +10 at top stick.

This means my normal pitch curve is something like 30-40-50-75-100  basically I dont get full negative in normal mode so it doesnt slam into the deck.  in idle up the pitch curve is as you have stated 0-25-50-75-100 this means you get full range on the pitch.

Newbies may set the mid stick to have +5-ish of pitch and -4 ish at bottom stick so in that case your 0-25-50-75-100 curve would work in normal mode but going into idle up wouldnt give you anything different.

[Sao]

No your getting that bit wrong.

The pitch figures 0 25 50 75 100 equate to 0 Degrees pitch at Half stick IE the 50% mark.

The idea is you have the same amount of pitch above and below the mid stick point for inverted flying.

IE pitch stick at bottom with curve set to 0% should equal your macimum negative pitch value -10 Degrees or so  50% equals 0Degrees pitch and 100% should equal +10 degrees of pitch (figure of 10 is guestimate it might be above or below that)

So to prevent having loads  of negative pitch in when the heli is spooling up I either reduce the amount of negative I have at bottom stick to around 2 to 4 degrees OR I start of with throttle hold on and put the stick to the middle then take throttle hold off and the heli spins up to full power with 0 degrees of pitch on.

So when you lift thhe stick above half way then the heli starts to lift off.

Now you can set it up to hover at half stick but personally I dont like this method as it means you dont get symetrical pitch and If you set up idle 1 to have symetrical pitch when you swap between normal and idle up you get a bit of a jump as the pitch position will suddenly change.

I use different headspeeds in normal and idle up as i like something a bit softer for landing and brief hovers, I spend most of my time in idle up at full power as bert has written to have everything working at max efficency, problem is on the whore at 2600RPM its not very stable when trying to land in windy conditions so i have normal mode set lower to tame it for brief periods.

this is probably getting realy confusing now but stick with it and it will 'clik' suddenly and make perfect sense.

[scoot]

what me Sao?

anyway I'll jib out here I know what I mean but am having difficulty putting it in words.

Q, normal to me is normal I wouldnt say idle 1 is my normal flying mode.  Normal is no idle up and yes I have 0,90,90,90,90 for the throttle in idle up I have 90,90,90,90,90.

[Sao]

Scoot no, not you, I was replying to aaron but yours and berts posts slipped in before I got my reply up.

It is a problem when three of you are trying to all give advice and you all do it slightly differently  

I never use normal mode for flying about as I am bound to forget and try to hover inverted in normal and have the motor shutdown on me. I always flip into one of the idle ups and go fly, then when landing I flip back to normal to tame it for a breif bit whilst landing.

[scoot]

sorry mate.

Yeah your right I as soon as I lift off I flick into idle up as well.

Anyway like I say I'll stand back and let you carry on so we dont confuse him even more....LOL!!!!

your doing a grand job.....        

[davidcollins001]

aaronb @ Fri May 06, 2005 12:13 pm wrote:

Cheers David, that does help.

So for a normal flight (no inverting) I should set up the Tx like this for eg:
Throttle curve 0 80 80 80 80
Pitch curve 0 25 50 75 100

That should give me a setup that is:
Stick down = no movement / flat blades
1/4 stick = 80% throttle (blades properly spinning) / 25% pitch (heli going light)
1/2 stick = still 80% / 50% pitch (heli lifting there or there abouts)?????
Anything above half with the stick is goes to increase the rate of climb????

It seems like you are getting to grips with the theoretical side of this. The next step is to think about the reality of what is actually happening. You need to look at your setup, and figure out what is happening mechanically.

If you have everything set up for 0* pitch as the minimum, increasing to +10* pitch, - at low stick throttle is 0 and blades will be flat and the rest is as you said, the actual stick position at lift off may be different dependant on other things, but that is for fine tuning.

If you add into the mix that you will want some negative pitch so that your heli doesn't dissapear on you in a gust, then you can mechanically set say -5*, this means that at low stick you will have 0 throttle, with -5* pitch

It may help to start thinking of the pitch curve in degrees so:
throttle  0 80 80 80 80
Pitch    -5 0   3   6   10

I hope this doesn't confuse you

[Sao]

Unless your trying to maint 0 Degrees at mid stick in which case it will be

throttle 0 80 80 80 80
pitch    -5 -2.5 0 5 10

Or thereabouts

[aaronb]

Ahhhhhhhhhh yes I see.

Those last 2 posts have really helped.

I was also getting confused with pitch curve on the Tx and the actual degrees of pitch needed. I was assuming that 0 degrees of pitch wouldn't hover and so 0 degrees would be bottom stick ie 0%.

Right ok. So thats really helped things in my head.

So is "Idle up" just another name for acrobat mode? It changes the settings of the curves? So you could hover in normal mode (What we've been talking about) then flick switch and go into acro mode?

YES / No.  

[Sao]

YES

[scoot]

0* of pitch will NOT hover.

[Sao]

Scoot is correct, the reason I keep ) degrees at mid stick is to the heli responds the same upside down as correct way up.

Hover pitch is somewhere around 6 degrees dependent on heli weigth set up air conditions etc etc.