Inverted/transition performance?

[squeky]

I've been starting to do flips with my CopterX 450 and see a big difference between doing them in the sim (Realflight 4.5) and "in real life". Flybar weights are removed, no binding, and performance is otherwise very good. -11 to +11 pitch. 20C batteries that are relatively new. Throttle and pitch curves as outlined in Finless' videos.

I'm just not sure if this is what most helis do or is mine underpowered or needing more amps pushed through the system? Anyway, it's like my inverted performance when transitioning between upright and inverted is really dull. I can flip it over quickly, give a lot of negative collective, and it doesn't shoot off into the sky like it does when upright. It's not bogging the motor, at least it's not sounding like it. I then go to 0 pitch, flip it back over, then can take off like hell upright. Any ideas?

[Bob O]

First thing to verify would be your curves.

Pitch curve for Stunt/Idle Up should be 0-25-50-75-100.

Throttle curve for Stunt/Idle Up should be 100-95-90-95-100 at a minimum, IMO.

[squeky]

Originally Posted by Bob O

First thing to verify would be your curves.

Pitch curve for Stunt/Idle Up should be 0-25-50-75-100.

Throttle curve for Stunt/Idle Up should be 100-95-90-95-100 at a minimum, IMO.

Correct, those are the curves I'm running (but will triple-check when I'm in front of the transmitter). Headspeed is a calculated 3000 rpm.

[Bob O]

Is your head set up for zero degrees pitch at mid-stick? Or do you hover at mid-stick.

[squeky]

Originally Posted by Bob O

Is your head set up for zero degrees pitch at mid-stick? Or do you hover at mid-stick.

Yes, 0 degrees at mid stick which makes it hover about 3/4 stick. When I'm upright and give negative, it drops like a rock out of the sky, so the negative pitch is there too.

[Rªzª]

yeah sounds fishy. unplug the motor and test the pitch ranges with a pitch gauge on the blades when in the mode you are flying in... something must be off

[squeky]

OK, thanks. I'll report back my findings later tonight.

[Mr.Andersen]

If you haven bottomed the left stick inverted it can be your not goving enough negative pitch becouse when going from upright to inverted your supose to go from 3/4 throttle stick to less then 1/4 stick to first top the fall and from there to inverted hopver posission.
If you have bottomed the stick check your actual pitch.

[bloftin]

+1 on the pitch gauge. Your pitch curves look good on the transmiter, but check to see what your actual colective blade pitch is with a pitch gauge. Also can someone tach your headspeed for you?

[hornet dave]

Pitch gauges get you close, but I always find that I need a little adjustment to the head in order to get even performance between upright and inverted. Adjust some links in your head a turn or two to get more negative pitch until the heli reacts the same upright and inverted.

[JasonJ]

I am guessing your setup is fine. When I started messing with inverted it took awhile to realize I wasn't giving enough negative input. Despite sim use, it doesn't feel the same in real life. It always seemed like the helicopter was falling too much until I actively made an effort to give more negative than I thought I needed to.

You might find you are just not giving enough input, especially if you are not bottoming out the stick.

[nyc863]

are you using the included copterx blades? they have (or had) assymetric profile. The ones with the flame design on them.

[squeky]

Originally Posted by nyc863

are you using the included copterx blades? they have (or had) assymetric profile. The ones with the flame design on them.

Nope, using HobbyCity carbon fiber blades.

I think I found a problem -- +10 and -7.5 are my pitch settings. Could have sworn I setup to +11/-11. Anyone know why are they not symmetrical? Thanks for all the responses.

[nyc863]

because at mid stick, you won't be seeing 0 pitch?

[squeky]

Originally Posted by nyc863

because at mid stick, you won't be seeing 0 pitch?

I guess the .5 is my error? Man, I feel like such a n00b today. Thanks everyone.

[Bob O]

squeky,

Check this post:

https://www.helifreak.com/showthread.php?t=203491

Maybe it will help you get even pitch.

[tim-schnabel]

Oh, I know why...

had the same problem, and noticed it when measuring pitch with a gauge. The pitch slider is not centred.

Decrease the lenght of the connection rods to your servos, and then reset the whle head to give you zero at centre stick (yeah, im sorry, youre gona have to go through all the links again, to get all parts on the rotor head horizontel at mid stick, like finless explains in his ccpm vids).

When the pitch slider is in the middle and mid stick, THEN you will get exactly the same neg and pos pitch at full ranges of your stick movements. It may take a few tries to get it there.

Have fun and good luck,

Tim

[Rªzª]

Originally Posted by squeky

Nope, using HobbyCity carbon fiber blades.

I think I found a problem -- +10 and -7.5 are my pitch settings. Could have sworn I setup to +11/-11. Anyone know why are they not symmetrical? Thanks for all the responses.

Theres a few reasons this can happen. easiest fix is adjusting the links on the bladegrips. the best solution however is to start from the servos and make sure everything (all arms) are perfectly horizontal from there up.

You should also make sure there is nothing really odd setup in your radio. i.e. make sure all the travel adjustment screen shows -100 to +100 for aileron elev and pitch channels

[squeky]

Thanks guys, I started the head setup over and got it -11-0-+11. Can't wait for flyin' tomorrow

[squeky]

Whoa, what a difference in inverted performance. Who would have thought? :o I can start working on my rolling loops too (love the way they look).

I had to increase my swash mix as well, so I never could have had -11 and +11.