Why are pitch curves in %?

[RCheliski]

Hi folks!

I have always wondered why, when many people are discussing pitch curves, they refer to them as a percentage, rather than the the actual degree. It just doesnt seem right to me. If my max pitch is -12 and +12, and yours is -10 and +10, or if the mechanical setup is different, and we are discussing possible new pitch curves, our percentages across the entire 5 point curve are going to be different. Am I missing something really simple here?

Ed

[McKrackin]

Pitch curves should all be the same from 50% up...Everyone.....

The difference is in the swash mix.

0-25-50-75-100 should be the pitch curve in every radio on the planet in my opinion.Idle up that is.

Adjust your swash mix or limits in your FBL controller for more or less pitch.

[ahahn]

Originally Posted by RCheliski

Hi folks!

I have always wondered why, when many people are discussing pitch curves, they refer to them as a percentage, rather than the the actual degree. It just doesnt seem right to me. If my max pitch is -12 and +12, and yours is -10 and +10, or if the mechanical setup is different, and we are discussing possible new pitch curves, our percentages across the entire 5 point curve are going to be different. Am I missing something really simple here?

Ed

A pitch curve is simply the relationship between the location of the collective stick and what fraction of the range a transmitter is sending out to the heli.

The actual pitch in the heli will depend on the throws in the linkages, where you put the balls on the servos etc.

We think about % because that's how the transmitters are setup. Off the top of my head, I am guessing the actual pitch (in degrees) linearly follows the transmitter pitches, but that also depends that your linkages are setup nice and 90 degrees with zero being in the center.

Lots of ways to screw up!

[banditpowdercoat]

Your pitch curve is a percentage of Servo travel. 0-100% You do not use your Pitch curve to limit servo travel. That's what Endpoints are for. So someone running 10* Pitch might have a End Point of say 97. And another person may have 12* Pitch, his endpoint is 102 maybe. For example. But BOTH will have a 0,25,50,75,100 Pitch curve in radio. Same curve, different servo travel becase End Points tells servo how far to travel at 100%

[burntclutch]

% in rellation to.......

[RCheliski]

Originally Posted by burntclutch

% in rellation to.......

Exactly. Percentages in relation to what? I am not a newby and I understand the concept of using percentages in the transmitter. But let's say a newby wants to learn to hover. I, as that newby, want to understand the degree at hover as opposed to the percentage at the transmitter. Using percentages at the transmitter, is simple. But that doesn't tell the newby anything about degrees in relation to that hover.

[McKrackin]

Then they need to ask the right question.

"What pitch curve should I use" is a totally different question than "How much pitch should I have"....

If you ask about pitch curves,you are not asking about pitch.


And when a newbie asks either question,more than half the replies from experience include the curves as well as what degree of pitch to use.

Learning to ask the right question is as much a part of it as anything else.

You're looking at it wrong and not understanding the difference.

[SYMAWD]

Originally Posted by RCheliski

Exactly. Percentages in relation to what? I am not a newby and I understand the concept of using percentages in the transmitter. But let's say a newby wants to learn to hover. I, as that newby, want to understand the degree at hover as opposed to the percentage at the transmitter. Using percentages at the transmitter, is simple. But that doesn't tell the newby anything about degrees in relation to that hover.

Degrees in the TX wouldn't work because the TX has no idea how much throw your servo has or how your heli's head is setup.

[McKrackin]

Originally Posted by RCheliski

Using percentages at the transmitter, is simple. But that doesn't tell the newby anything about degrees in relation to that hover.

How does it not?

If 0% is -12° and 100% is +12° and your curve is 0%-100% linear....then 50% is 0° and 75% is 6° and 25% is -6° and so on and so on and so on.....

Don't make complicated pitch curves.....0-25-50-75-100 is the best possible way.

If you want less negative pitch,change the lower positions but leave 50% and up alone....75% will still be +6°.

[banditpowdercoat]

Originally Posted by McKrackin

How does it not?

If 0% is -12° and 100% is +12° and your curve is 0%-100% linear....then 50% is 0° and 75% is 6° and 25% is -6° and so on and so on and so on.....

Don't make complicated pitch curves.....0-25-50-75-100 is the best possible way.

If you want less negative pitch,change the lower positions but leave 50% and up alone....75% will still be +6°.

Wrong. if you want less pitch, Use ENDPOINTS!. Just changing the low and high value on pitch curve and leaving 25%-75% the same will result in a non linear piutch curve becoming a lot less sensitive above 75% and below 25% You have now lost your consistency in Pitch feel.

You essentally made a -Expo pitch curve with less overall pitch.

[McKrackin]

Originally Posted by banditpowdercoat

Wrong. if you want less pitch, Use ENDPOINTS!. Just changing the low and high value on pitch curve and leaving 25%-75% the same will result in a non linear piutch curve becoming a lot less sensitive above 75% and below 25% You have now lost your consistency in Pitch feel.

You essentally made a -Expo pitch curve with less overall pitch.

Wrong?
I said leave the 50% and up alone....linear.

You will not lose the consistent feel below 50% because it's not flying.

I'm talking about normal mode and I clearly said all idle up curves should be 0-25-50-75-100.....I also said use limits in the FBL system or swash mixes to lower overall pitch.....

Read it all.

Originally Posted by McKrackin

Pitch curves should all be the same from 50% up...Everyone.....

The difference is in the swash mix.

0-25-50-75-100 should be the pitch curve in every radio on the planet in my opinion.Idle up that is.

Adjust your swash mix or limits in your FBL controller for more or less pitch.

[banditpowdercoat]

Sorry my bad Ernie. I honestly read it as you were changing the 50%-up to change max pitch

[mattmezz]

instead of trying to explain this to someone that isn't going to understand it anyway. point them to the vids in the setup 101 section where they should have looked in the first place before asking... sorry maybe that is a little lame but finless explains it.

http://video.helifreak.com/?subpath=...CPM_Part_1.wmv



http://video.helifreak.com/?subpath=...CPM_Part_2.wmv


http://video.helifreak.com/?subpath=...=curves101.wmv

[im4711]

Not wuite sure about the question. Pitch ranges are not in percentage. Tey are in degrees. However pitch curve setup is in percentage because everyone has somehow their own end points and you define the curve with percentage from that.

I would not recommend pitch curve settings copied from others without checking the real pitch values.

[McKrackin]

Originally Posted by banditpowdercoat

Sorry my bad Ernie. I honestly read it as you were changing the 50%-up to change max pitch

People are always in a hurry to say I'm wrong even if I am saying exactly the same thing as they are.


It's the bed I made....Time for a nap

[Wolfpackin]

Originally Posted by banditpowdercoat

Wrong. if you want less pitch, Use ENDPOINTS!.

I disagree with this...

Endpoints should be used to reduce/eliminate CCPM interactions.
Swash Mix should be used to adjust the pitch range.
...for flybar helis.

[McKrackin]

Originally Posted by Wolfpackin

I disagree with this...

Endpoints should be used to reduce/eliminate CCPM interactions.
Swash Mix should be used to adjust the pitch range.
...for flybar helis.

As well as some FBL ones like my 3GX...

Use the limits in the FBL controller in the others.

[youturnjason]

Originally Posted by McKrackin

How does it not?

If 0% is -12° and 100% is +12° and your curve is 0%-100% linear....then 50% is 0° and 75% is 6° and 25% is -6° and so on and so on and so on.....

Don't make complicated pitch curves.....0-25-50-75-100 is the best possible way.

If you want less negative pitch,change the lower positions but leave 50% and up alone....75% will still be +6°.

First if all, not everyone flies 12 pitch. Second of all 100% isnt automatically 12. Move The servo balls in one hole and your 100% becomes closer to 10 degrees.

The only reason you should have a pitch curve other than 0-25-50-75-100 is for normal mode where you can have something like 40-45-50-75-100 so you dont spool up with full negative collective.

[McKrackin]

Originally Posted by youturnjason

First if all, not everyone flies 12 pitch. Second of all 100% isnt automatically 12. Move The servo balls in one hole and your 100% becomes closer to 10 degrees.

The only reason you should have a pitch curve other than 0-25-50-75-100 is for normal mode where you can have something like 40-45-50-75-100 so you dont spool up with full negative collective.

That's exactly what I said.....50 and up stays the same and adjust the below 50 numbers to make less negative pitch....Again,exactly what I said.

Originally Posted by McKrackin

How does it not?

If 0% is -12° and 100% is +12° and your curve is 0%-100% linear....then 50% is 0° and 75% is 6° and 25% is -6° and so on and so on and so on.....

Don't make complicated pitch curves.....0-25-50-75-100 is the best possible way.

If you want less negative pitch,change the lower positions but leave 50% and up alone....75% will still be +6°.

I know not everyone has 12°
The math is the same.

If you have 10°...0% is -10°...50% is 0°...100% is +10°

That means 25% is -5° and 75% is +5°

If you have 8°....0% is -8°....50% is 0°....100% is +8°

That means 25% is -4° and 75% is +4°

They said the percentage tells the flyer nothing when in fact it tells it all if you know your pitch range.
Set it up with 0° at 50% and put a pitch gauge on it at 100% and adjust it to make equal negative as positive....Then the % will tell you exactly what your pitch is at every single point in the range.

[youturnjason]

I meant to quote the OP sorry

Originally Posted by McKrackin

They said the percentage tells the flyer nothing when in fact it tells it all if you know your pitch range.

Summed it up right there.