Trex 550 FBL, No Lift until 3/4 stick!

[smitti2002]

Good Morning!

I have a quick question regarding the set up on my 550. I've finished the build and I am having an issue with lift. I have a head-speed of 2200 at a flat 70% throttle curve, 550mm blades. -11 at 0 stick, 0 at mid stick and +11 at full stick. For some reason I don't get any lift until about 3/4 stick? I'm not sure what could be causing this issue. I've looked at the pitches throughout the stick inputs over and over again and it is correct all the way around. All of my EPA is still at default setting of 100% both ways. Once it does lift it is great but again, it's not happening until about 3/4 or more, any idea what could be causing this? Be easy on me, I'm fairly new lol. Thanks in advance!

[aussiefly]

Does 3/4 stick even sound all that surprising with 70% and -11 to +11? I'm That's 5.5 degrees at 70% to hover - I'm no expert but I think that's about right or at least in the ballpark, maybe should hover at a tiny bit less stick but not much I'd say...

If you're worreid put the pitch range to +13/-13 and you've a bit more room to play with.

[STAZZ]

Well, it's quite obvious that there will be no lift in -11 degrees untill 0 degrees on your blades. Then you need some lift to overcome the weight of the model, that's normally about +5 degrees.

Can you remember where the stick is when it lifts of the ground? Then land, and with motor off measure your pitch at this exact point. I guess it will be about +5 degrees. So, nothing is wrong.

[smitti2002]

Thanks for the response. Again, I'm fairly new and I have been getting a lot of help from a friend who lives out of state and actually suggested that I be at around 10 degrees both ways, I originally had it at around 12.5 but he said that would be too much, clearly he was wrong lol . I will make the adjustments tonight and go from there. Thanks again!

[smitti2002]

Yea, stick is right at around 3/4 or more. From what I just seen I need to go to around 13 degrees both ways. I will make those adjustments and I should be good to go. I was told by a friend who has built several helis to go with around 10! I'm not sure if he just told me the wrong thing or what. Thank you for your response!

[Toocool4]

Hover point should be just above mid-stick. When you say you are running 70% flat @ 2200 is that governor or just flat curve ungoverned?

If that is governed either put your head speed up, if not governed try a higher % for more head speed.

The manual suggests -12.5 to +12.5 I think, well for me anyway I am flying the T-Rex550 V2

[smitti2002]

@ Toocool4, it is governed. I am going to be adjusting my pitch and will probably raise the head speed as well and I am thinking I will be fine. I guess it was just a very simple common sense type of problem lol.

[Toocool4]

Originally Posted by smitti2002

@ Toocool4, it is governed. I am going to be adjusting my pitch and will probably raise the head speed as well and I am thinking I will be fine. I guess it was just a very simple common sense type of problem lol.

If you have a look in the manual it should give you recommended head speeds, for my V2 i am running 17T pinion Normal 2000rpm, IU1 2300rpm and IU2 2550rpm.

Oh i am running 520mm blades.

[smitti2002]

I will have to jump on and download a manual, this was a build from an HK kit and it didn't come with one. I am running a 17T as well with a 1220kv motor. I've seen suggested head speeds anywhere from 1900-2500 so I wanted to shoot for the middle. I don't do any type of hard flight right now, strictly simple flight for a while lol. You have been super helpful, it's greatly appreciated!

[Toocool4]

Originally Posted by smitti2002

I will have to jump on and download a manual, this was a build from an HK kit and it didn't come with one. I am running a 17T as well with a 1220kv motor. I've seen suggested head speeds anywhere from 1900-2500 so I wanted to shoot for the middle. I don't do any type of hard flight right now, strictly simple flight for a while lol. You have been super helpful, it's greatly appreciated!

I have the same motor as you and if you want to shoot for the middle, try 2300rpm. I fly most of the time in IU1 which is @ 2300rpm, I can do everything I want at that head speed I only go to IU2 @ 2550rpm if I want to do crazy stuff not that I am capable of doing too much crazy stuff.

Forget the 1900rpm, you will hardly get off the ground.

Correction my IU1 is 2250rpm

One more thing since you are using the same motor as me run the PWM Rate @ 8KHz not the 12Khz default

[smitti2002]

Ok, I'll go with 2300 and see how it goes. Is the PWM rate adjusted in the governing setup? I am using a Castle Talon 90. Thanks again for your help

[Toocool4]

I use Talon 90 too, look under the Motor Tab for your motor PWM

[smitti2002]

Sweet! Thank you so much! I will be sure to keep you updated on how it goes if you would like

[Toocool4]

Good luck, have fun.

[Imzzaudae]

Please post.
What transmitter are you using.

What Throttle Curves Normal and Stunt Mode
What pitch curves. Normal and Stunt Mode

For someone just starting out with this helicopter. Plus and Minus 10 is plenty of pitch. You can get away with plus and minus 8 and still have plenty of power. All 13 deg of pitch will do is give you an overly sensitive collective stick.

With a head speed in the 2200 RPM range this helicopter should be a homesick angel at 3/4 collective.

If you are an inexperienced collective pitch pilot
please pm me.
Ron

[smitti2002]

Ron, I tried to message you and it said that you have exceeded your message limit until you clear some space

[Imzzaudae]

Hey. Ya I was a bad boy. Had like 400 messages.
I still help a lot of guys with micro and they pile up quick.

Deleted them all and I'm good to go .