Rotor Tuning, parameters the same?

[Varelco]

I’ve been going through the Spartan tuning guide and is it just me or do some of the parameters practically do the same thing based on their descriptions? I’m talking primarily rotor tuning, for example;

Agility – adjusts roll and flip rates
Mid-stick agility – increases agility (which is speed/rates is it not?)
Cyclic rates - Dual rates, increase/decrease cyclic throw, therefore roll and flip rate?

Pitch up compensation – compensates pitching up tendencies in FFF
Elevator pre-compensation – compensates pitching up tendencies in full collective FFF

Cyclic response – slows/speeds up stick response
Cyclic exponential – slows/speeds up stick response

Can someone explain how you actually differentiate between these parameters and the impact they have. I enjoy my Vortex and I love that it has so much flexibility when it comes to tuning but I’ve have found it difficult to understand exactly what parameters need changing should I want a different flight characteristic, everything else in terms of setting up gains and mixes are self-explanatory.

Thanks,
Matt

[trillian]

On the Pitch-up comp vs Elevator pre-comp I think the difference is that pitch-up comp is to counteract a tendency for the rotor disc to pitch up in fast forward flight but the elevator pre-comp is to deal with a tendency of the tail to dip when doing a fast climb-out due to the extra drag of the tail.

Not sure about the differences in 'agility' vs 'cyclic response'. But cyclic rate sounds like it's the overall throw / travel.

I must admit I have only read up on the specific things I wanted to address at the time, just assumed these other things are explained as well somewhere.

I have been using the stock 3D preset with only very minor adjustments but found the paddle weight and paddle dynamic very interesting in version 2. (basically simulating a virtual paddle that can morph depending on the stick input)

[Varelco]

Thanks for the input Sheryl, your explanation would make sense for the difference between pitch-up and elevator pre-comp but the elevator pre-comp states that about pitching up in fast forward flight too, not a climb out. So if your heli is pitching up in fast forward flight which parameter do you change? Can you see what I mean they are both the same.

[trillian]

Thanks for the input Sheryl, your explanation would make sense for the difference between pitch-up and elevator pre-comp but the elevator pre-comp states that about pitching up in fast forward flight too, not a climb out. So if your heli is pitching up in fast forward flight which parameter do you change? Can you see what I mean they are both the same.

Yeah I have only changed the pitch-up compensation but didn't need to change it on the TDR (and maybe not on the Faifa I don't remember). For cyclic response I have only used the agility and in a couple flights I was getting the feel I like and then haven't played with it any further.

[waveydavey]

I'll attempt to add my thoughts to the elevator pre comp and pitch up parameters. The pre comp will help you with unwanted nodding in elevator inputs, so if you stop elevator input and the model appears to bounce (over/undershoot) add pre comp to stop it. If in forward flight the heli needs forward elevator to stop it from ballooning upwards then add pitch up compensation to stop it.

[Varelco]

The pre comp will help you with unwanted nodding in elevator inputs, so if you stop elevator input and the model appears to bounce (over/undershoot) add pre comp to stop it.

See I thought it would be the elevator pre comp that helps the heli track straight when you give it full pitch forward flight. There used to be elevator debounce to counter elevator bouncing/nodding, this no longer exists however and the a rotor gain deals with that:

• Rotor Gain - Controls the amount stabilisation that is applied to the main rotor. If you experience main rotor oscillations on hard stop manoeuvres (for example at the end of rainbows) or porpoising during fast forward flight reduce this value.

[philipjdall]

Don't have any more vx1's anymore but I think you can still access debounce through the advanced PID menu. Point is that 99% of the time debounce can be ironed out with rotor gain, hence the reason it was moved as people went straight to debounce which actually made things worse.

Agree, there are too many settings and it can get confusing. I found it best off tuning with the basic settings most of the time. Anything else got too confusing as to what was doing what.

[waveydavey]

I think we all get caught in the what to adjust loop as Phil says there are a lot of parameters and some will invariably interact with each other. I can only speak from experience and the description I used was what worked for me. The 700n needed a fistfull of forward elevator to stop it from rearing up in FF, I added pitch up compensation to stop it from doing this, this didn't change the elevator Pre-comp nor have any effect on this motion. The Raptor, which I still haven't fixed by the way, having too much fun with the n appeared to need pre comp to stop the tail bouncing. The debounce is gone so unavailable.

[myxiplx]

Here's my understanding:

Agility: Changes the maximum rotation rate during flips and rolls.
Mid-stick agility: Not 100% sure as I never flew flybar, but I believe this makes the helicopter react more quickly. Low agility would create a more docile and stable helicopter, high agility creates one that is very 'sharp' for want of a better word.
Cyclic Rates: Same effect as dual rates on the TX. Will reduce effective maximum roll rates, so interacts with Agility. The main benefit is to give you the option to use bank switching to give you dual rates with more precision than setting them in the TX.

Elevator pre-compensation: Always adds some elevator when you add cyclic pitch. Use this if your CoG is off slightly and you're seeing the tail rise or fall during a pitch pump.
Pitch up compensation: Use this if the helicopter has a tendency to nose up in fast forward flight. The difference to the elevator precomp is that this corrects the situation where the nose is rising *without* a change cyclic input.

Cyclic response - smooths out cyclic input a little. Will interact with Agility and mid-stick agility, seems designed to specifically allow tuning for different dampers in the head.
Cyclic exponential - Makes the stick more gentle near the centre, allowing for more precise adjustments when hovering. On the vortex it's recommended to use expo in the FBL and disable expo in the TX. Transmitter expo is applied individually on aileron and elevator, and while that's great for planes, it creates some odd effects on a helicopter, most noticeably in piro manoeuvres. On the vortex, expo is a circular function, giving you a smooth expo and a consistent response all the way around the cyclic.

[philipjdall]

Mid stick agility is the speed the heli reacts off centre. It is unlike exponential in that it effects the loop, and not the input request into the loop.

Good for getting sluggish machines to bite - although that is never really a problem with the vx1!

[tomatwalden]

Elevator pre-comp is definitely a compensation against the drag of the tail in collective pitch inputs. You can see it's effect on the table by moving the collective pitch up and down and see the swash move in "an arc" to help lift the tail ... It caught me out recently when trying to ensure a level swash ...

[Varelco]

Some good input into this thread thanks. Some things appear to be a bit clearer now, but not all. It would make sense to me if each parameter describes what effect it has either to stick input or servo output, I got this input from elsewhere;

MID STICK AGILITY is how fast the servo is driven by stick input.
CYCLIC RATE is total pitch allowed by stick input.
PIT UP COMP you nailed it.
ELE PRE-comp mixes some ELE to collective.
CYC RESP is the delay response from stick to heli
EXPO is how sensitive or not a %age of your mid stick range is.

So your CYC RATE Provides 10* we'll say. Neither Mid STK AG or AGILITY will change that 10* but will drive the servos to that 10* faster or slower. EXPO will raise or lower the throw around midstick.

That kinds of description makes more sense to me.

I think it would be benefical if the tuning guide was more detailed and perhaps gave an example. The references to flybars doesn't help, especially nowadays, if you have joined the hobby in the past 3 years the chances are you have never seen a flybar let alone fly a heli with one and tuned it. I had a flybarred heli when I was learning but I never changed anything so I dont know either. If you went to a "newbie change this parameter its like halving your flybar weight" they wouldn't have a clue.

[myxiplx]

The thing is, the actual effect these parameters will have can only be given in a general sense. And I think Angelos' descriptions are pretty good. You do need a bit of knowledge to understand this stuff, but you're going about it the right way. The only way to learn all of this is to talk it through with other people in the hobby.

The problem is that different helicopters need different settings, and may behave slightly differently. Even the same helicopter with a different motor or servos can require totally different settings. And the mechanics of the helicopter and these settings all interact.

[Varelco]

The thing is, the actual effect these parameters will have can only be given in a general sense. And I think Angelos' descriptions are pretty good. You do need a bit of knowledge to understand this stuff, but you're going about it the right way. The only way to learn all of this is to talk it through with other people in the hobby.

The problem is that different helicopters need different settings, and may behave slightly differently. Even the same helicopter with a different motor or servos can require totally different settings. And the mechanics of the helicopter and these settings all interact.

It's mainly curiousity thats driven this thread as I'm wonder how much I can tune this unit. I actually want to remove some of the aggression in my Forza but keep its agility. I understand that you have to generalise a little due to the diversity of each heli but ultimately the effects of changing a certain parameter should remain the same. I still don't think the guide is clear, hence why I asked. I have got clearer answers from people on this thread than on the tuning guide.

[Angelos]

I’ve been going through the Spartan tuning guide and is it just me or do some of the parameters practically do the same thing based on their descriptions? I’m talking primarily rotor tuning, for example;

Agility – adjusts roll and flip rates
Mid-stick agility – increases agility (which is speed/rates is it not?)
Cyclic rates - Dual rates, increase/decrease cyclic throw, therefore roll and flip rate?

Pitch up compensation – compensates pitching up tendencies in FFF
Elevator pre-compensation – compensates pitching up tendencies in full collective FFF

Cyclic response – slows/speeds up stick response
Cyclic exponential – slows/speeds up stick response

Can someone explain how you actually differentiate between these parameters and the impact they have. I enjoy my Vortex and I love that it has so much flexibility when it comes to tuning but I’ve have found it difficult to understand exactly what parameters need changing should I want a different flight characteristic, everything else in terms of setting up gains and mixes are self-explanatory.

Thanks,
Matt

Pilot controls (operate on the sticks)
Cyclic rates - They are similar to the steering ratio of a car. It defines how much you need to move the stick/steering to achieve a specific turn rate.
Cyclic exponential - Exponential affects the profile of the steering ratio. It will slow down the the behavior of the stick around center but the overall full stick response is still the same.
Cyclic response - Works like a delay to smooth out the stick movements. This avoids overloading the rotor if you move the stick too fast. Crude analogy, it tries to avoid the roll wobble you'd get if you tried to steer your car too fast.

Heli behavior (operate on the heli)
Agility and Mid-stick agility control how the stabilisation operates on the heli. Changing them will ultimately make the heli roll/flip faster but the overall feel of the heli is different. They cam make the heli feel lighter and more floaty or heavy and want to hold its position. There isn't a better way to describe it, you just need to try it. As a crude analogy imaging changing the suspension of a car or driving a totally different car. You just get a totally different feel.