why this???

[matador_24]

Hello guys, I am running a raptor 30 v2, OS 37 sz, revolution muffler, helimax 550mm carbon blades.

Pitch -9, 0, +9 (0, 25, 50, 75, 100)
I have +5 pitch at 75% throttle
my throttle curve: 100, 74, 60, 74, 100

Why am I hovering at 85% collective stick???????
I thought I should be hovering at 75% throttle....

I am not sure about the mixture needle, I just opened it a lot at the beginning and started to close it until I got a nice IDLE, after that I started to close the main needle until I got a nice climb, just as described in raptor technique, the heli flies great is just that I thought I should be flying at 75% throttle, 85% sounds too much up for me.....



Is that normal???? what is going on????

[schucb]

Make your throttle curve flatter. I run around 85 in the middle of the stick.

How rich is your motor running?

[matador_24]

1.25 open turns counter-clockwise. 160F. If I open more it gets too rich.

I think 85% throttle in middle point is too much, no?

it shouldn't be more than 60-65% as far as I know....

[Helirat]

Check your linkage to see were the carb is set at when you are at 3/4 stick you mite
need to redo your throttle curves. Your RPM mite still be to low at 3/4 and thats
why your not getting lifting

[matador_24]

Helloooooooo

Thanks for your answers... I think I figured it out and I am sorry for the mistake. However, I will not have the chance to prove it until sunday!

my pitch is -9, 0, +9 with a linear pitch curve of 0, 25, 50, 75, 100

Therefore, at 75% throttle I must be haveing +4.5 and at 85% about +6 and I guess that is why I am hovering at the stick position and that is why my heli bogs while flipping back!!!!! because the change in collective hovering normally is from 85% to 15% inverted!!!!

I can not fly until sunday but I am almost sure it is that.. does anyone back up my theory?????

Thanks!!!!

[matador_24]

How should I set my hovering point?????

I hover and I adjust my curve until I get the hovering point at 75%????? or I should just set +6 pitch in the 4th collective point and hover where it gets?????

[forjer]

Most helis can be setup to hover with 4-5 deg of pitch. So once you have your head pretty well dialed, set the pitch gauge to 4.5 deg and move your stick till the gauge shows your desired hover pitch. Then, mark your stick position on your transmitter. Start with some throttle curve and go hover. Once you've gotten to a nice steady hover, take a glance at your hover stick position in relation to the mark you made on the transmitter. Now adjust your throttle curve until it hovers at your desired hover pitch. The adjust the rest of your curve so the RPMs remain constant throughout the entire pitch range.

OK...I'll be honest. I've never tried this myself, but I might just go do it.

[matador_24]

mmmmmm, are you sure????

I would think +4.5 is pretty low to set as hovering point.......

I thought more about +5 or +6

[heli]

You want a 5 - 6 deg pitch to hover.

It sounds like your mechanical settings from servo to your motor are off.

Set your radio to 50% and Zero Deg (Collective Stick). Check to see if your carb is at 50% open, if not then your mechanical setup is off. Once you can achieve proper mechanical setup the rest should be very easy to set. It is important to have linear movement with your throttle servo to the engines carb.

I have a very detailed document that explains this in great detail. If you need it let me know and I will search it out.

[heli]

1.25 open turns counter-clockwise. 160F. If I open more it gets too rich.

I think 85% throttle in middle point is too much, no?

it shouldn't be more than 60-65% as far as I know....

I ran my motor around 200F - 220F your a bit rich in my opinion.

The middle point when in an idle up position is usually 65% (when a governor is used most use a v curve of 100 INH 65 INH 100 (this is for a 5 point throttle curve)).

[heli]

Here is where the document I mentioned originates: http://www.myraptor.net/r50v2/r50v2_throttle_linkage.html

The setup docs here are highly detailed and to the point. This should help you solve your issue.

[matador_24]

I am sorry, I do not understand the position of the carb in the drawing, it looks straight how it is installed and when the engine is mounted, the carb finishes in a certain angle in comparation with the bottom of th engine. It seems to be in another angle. How I see it in the drawing, the 0 pitch seems to be about 30% of the throttle arm.... is it right?????

[heli]

0 deg pitch is 50% throttle (center stick). The carb should be half way open.

While the setup is as above the servo horn and carbs horn should be parallel to each other.

[matador_24]

Thanks a lot for your time!

I got it. Just one question:

In the first image of the website, I see the image of the engine with the full close and full opening arm position. 50% of the carb opening shouldn't be when the arm is EXACTLY in between both full positions? (full and close positions).

In my set up I have 50% collective (0 pitch) when the arm is between the both full positions (close and open)

[heli]

If I understand you correctly your Carb is 50% open at 50% Collective. If so then this is correct.

[matador_24]

thanks for all the help.... I finally found out the problem, of course, after reading your suggestions.... finally my carb was opening about 80% at full throttle, apparently the engine came with the throttle arm in a wrong position and It was not fully opening at 100%, I fixed it and now I hover at 70% with a hell of power... amazing OS 37....

Thanks to all of you guys....