Tz 50 not wanting to fly?Pitch settings?Blades!!!!!!!!!!!!!!

[Y@nkee]

Hi.
I just finished building my TZ 50(identical to stinger50) and went out to give it its maiden flight.
I set pitch to -5 +9 when setting the heli up for normal mode.
Fired up the engine(os 50 hyper)and set main needle to about 1,5 turns.
The engine fire at once and for the rich setting running very nice.
At first liftoff attempt the engine screamed and the heli was still at the ground.Lowered hoverthrottle and raised hoverpitch.
With some fiddeling around i got it airborne but it hardly wants to climb, it flies but have NO punch at all.
So, i raised my topendpitch to +11 and well when i give it full stick(throttle at 70 %) it wil climb a little better and the engie actually gets higher revs, so its not my engine bogging causing this.
It might be me setting rotor rpm to low but anyways i think with +11 it should climb faster than it does.
So i wondered can it be me having a to weak pitch servo on it? 4.4 kg i know its low but it should for normal flight be able to do the job.
My hover rpm is not screaming, but i think it should be more than enough to fly the heli.(dont have tac)
My setup is:
Tianzi TZ50
600mm glassfiber blades(the stock ones) looks just like the Gohbee stinger50 ones.
OS 50 Hyper with hattori muffler.
Futaba 401/9253
JR PCM 9X II

Btw i did hover and fly it around a bit and OMG is this thing stable, i trimmed it a couple off clicks on elevator and it hovered for about 10 secs handsoff.

[scottc]

I gotta say i love my stinger 50s as well, went to the stinger 90s now i kinda miss the 50 tho. but on the question. The way i set my pictch curves is i set the hover for 3/4 stick hovering with the pitch set at 0 degrees in the center and then set at least +9 to -9 this just works for me. mabey give that a try.my normal modes is the same pitch settings just with a little lower head spead.

[Y@nkee]

I did set my pitchcurve for hovering at 3/4 stick and 0 at midstick.
and the initial setup was smth like: -5 -2.5 0 +5.5 +9.
Just by eyeballing the blades it looked like it should have enough pitch to fly ok.
But when flying it acts like i dont have any pitch above hoverpoint, as i said it did get a bit better when i raised topendpitch to +11.
So, could this be a damper issue or just as easy as a to weak pitchservo?
But if it was the servo beeing to weak it should not get better when i raised the topend.
This is my first 50 size model but not my first nitro heli, so i think that just by hearig the sound of engine/disk i should have high enough rpm to have it have more "umph" than it does.
I do have a set of SAB 600mm carbon blades for it, but i dont think the prob is the blades, i think the sabs will fly better, but not that much better.
Had sab carbons on my 30(Nexus) and i really loved the way they flew compared to some cheap glassfiber blades i had on it.
Well i better get me a tac to measure my headspeed, and take it from there.

[scottc]

i dont think it could be the dampeners, i thought i could judge the head speed by sound to , you can get close tho. i have had my head speed checked thinking i had good head speed and been off 200 rpms and man did things come to life after turning things up.

[Y@nkee]

You are right Scottc, it is me not beeing able to guess my headspeed :arggg:
I did tac it with an airplane tac today on ground with 0 pitch, and well its a little bit higher in hover but on ground i taced it to about 1400rpm.
What is a normal headspeed for a 50 size stinger with plastic hub? About 1650 in normal mode and about 1850 in idleup?
I am sure if i raise it it will come to life.
Thanks for you input , if i could i would buy you a :guzzle

[scottc]

Jan a drink would do me good, a red beer comes to mind. the stingers 50 i had i was at 1850 to 1900 and it flu very well, that had to be hard to tac the heli with the air plane tac tho. have fun.

[Bonsai]

Sounds to me like you might have a clutch that is slipping..I say this because you have +11 degress on the top end and the engine is still screaming . I have a 50 and a 90. I am the TZ rep here in Kuwait... I dont get to spend much time online cuz im really busy but..... I have had clutch linings slip when they were brand new.. Also the raptor clutch is a direct replacement and is much more durable..just my humble opinion..and another place to look...
Dean

[Y@nkee]

What would be the signs to look for if it should be my clutch?
Smell of smth burnt?(the heli actually does smell as smth is burnt, not much but i do smell smth)
And if it should be my clutch, is there any cure for it other than buying a new one?
I did have it appart to fix a play i had in my startshaft(up/down), and the clutch/lining still looked as brand new.
If it was slipping wouldnt it get hot and have marks showing it?
Thanks Bonsai .
I actually think that you might pull me in the right direction here.
If its slipping it would explain the sloppy feeling it have when applying full pitch, it climbs, but slow at start and then getting faster(might be rotorrpm bulding up again after the initial drop cause of clutch slipping)

[Bonsai]

yhea you will smell it and there will be black soot around the bell area.( look around the frames with a q tip)...but the lining shouldnt look new it should show signs of black on it..look at the clutch itself and see if the edges are burnt... no you can change the lining .. I recommend the raptor lining as its a little bit thicker and holds better. just remove the old lining ( no easy job) and JB Weld the new lining inplace... from your discreption above I would say its slipping ..... Im sorry that I dont spend to much time online as Im really busy here.....If i dont answer right away dont be discouraged....I will get to it...
Dean

[flyinfool]

If the clutch is slipping the clutch bell will be very hot.
It is only the head block that is plastic. the stem is still aluminum and can take up to 2000 head speed.
The hyper is designed to run a 2000 head speed.
I am not sure about the FG blades being able to take 2000, I would keep the FG blades down to 1900 to 1950.
I run my Stinger 50 at 1850 in normal mode and 2000 in all idle ups.
Anything below 1850 makes for a very sluggish feel to the heli.

I just worked on a heli with someone yesterday that was set so rich that even at full throttle it would not get over 1250 head speed. You said that you are at 1.5 turns open so I do not think rich is your problem. after hovering for a minute check the temp of the engine back plate with your finger, you should be able to keep your finger on the back plate for at least 8 seconds before it feels to hot.

[Y@nkee]

Ok, i flew the heli for like 3 tanks today.
My engine was a little bit on the lean side (running ok but hot backplate)
My friend with the same ship also was there today, and i asked him if his had this problem, and his heli have the rocketclimbout i am wanting.(Ps , Dont get sick now, but i can fly rings around him :lol: meaning i fly way better than him)
Ok , i asked him how he had set up his pitch and got a weak answer(didnt really know)
So i measured his pitch: He had a FREAK(IN) :D 15 degrees at top and about 4 degrees at low end.
Mine is setup for linear pitch with -9 -> +9 degrees is this to little?
And how do you get a linear pitch curve if you need 15 degrees at the top to get this thing movin?
I bougt myself a skytach so i could know my headspeed, i am in normal curve at about 1800rpm, i know this is maybe a bit low but he is running about the same headspeed.
I flew around a bit doing loops and stallturns, on the exit of a stall turn i tried to go a bit negative pitch , and the heli really moved with negative input.
So, is it me not knowing how to measure my pitch or is it something in this head that acts different in flight than it does on the bench?
I do have a T-rex and well my pitchsettings on that is all fine. (measured in the same way)I have a JR pitchmeter for the TZ and the align pitchmeter for the t-rex.
Same way of measuring on both.
I dont have idleup setup on my radio so i dont know if it would climb better inverted, but my hunch is that it will.

[WJackson]

+9 to -9, 1650 normal, 1850 idle ups, awesome punch out. If your engine is screaming sound to me like clutch slippin'. what %of throttle til clutch engages?

[Y@nkee]

The chlutch engages as soon as i get above idle on the engine , i even have to stop the head turning on idle.(not much but it wants to turn it).
I think i got the engine mixture just about right now, maybe a bit rich at idle, but it sounds ok, got a nice smoke and the backplate is nice and cool after flying a tank.
i got myself a gov for it , so i am going to pull it out again to install the magnet and sensor, i will check the clutch again, but to me it dosent seem to slip.
I am going to put on my sab cf blades next time and set the gov for 2000 rpm on the head.
I had sab`s on my nexus to and OMG what a diff that was compared to the cheap fg blades i replaced on the nexus(Dont remember the brand of those)
But just by looks the grey fg blades i have on the Tz looks ok(very much like the sab`s).Maybe i should try the sab`s before i ramp up the speed?
Anyways with 1650 on the head in normal as you have StingerCrasy i think it hardly would lift itself of the ground.
But to me it seems like we have 2 helis here that act just the same, if my friend set his pitch as i have i think he would se the same thing as me.
Man i am loosing my hair over this( ok ,it was gone before :) )

Thanks for your input freaks :noteworthy

[flyinfool]

The amount of pitch you can run and the headspeed are related, the lower the head speed the more pitch you can run.

With the Gohbee and TZ helies it is very important that you make sure that the flybar is at 90° to the mainshaft while checking and adjusting pitch.

+/-9° Is a little low for the Hyper engine, You should be able to get +/-10° with no problem and possibly +/-11°

2000 is a good headspeed for your combination.

[WJackson]

you see huge difference w/ 2000 h/s jeff?

[flyinfool]

Big time.
The gearing is set up for the engine to produce peak power at 2000 HS.
By going from 1800 to 2000 all cyclic and pitch commands will be about 10% faster.
You may want to add some expo for the first flights at 2000.

Set it up for your 1850 in idle 1 and just put the 2000 in idle 2 so that you can turn it off if it is to wild.

Faster is better. :mrgreen:

I run 1850 in normal

If you are not yet into loops and rolls then stay with your 1650 in normal and 1850 in Idle up.

You will also notice that 2000 uses fuel faster so keep an eye on it unless you like surprise autos. :shock:

[WJackson]

I'll try it the next time i spool up. Gotta switch my gov on the 50 . Going to try the muti gov. , have you tried it yet?

[flyinfool]

I am still running either the GV1 or TJ Pro on all of my helies.

[WJackson]

I like the digi mode of the tj , but w/ the multi gov having an lcd to do calibration, it takes all the points you'd want and puts em in one package.

[gaanel]

I have the same problem. +9 / -9 produces a very slow climp out at full pitch but when inverted, the helicopter goes up like a rocket, even to the point of bogging the engine. This seems to be a common problem on the Gohbee.
According to David at Gohbee you have to unwind the 2 short links (called double links in instructions) that attach to the blade holders and the flybar. I wound them in until closed and then unwound them 2 times each. Then wind the links that run from the flybar to the swash (called mixing lever control link) IN 2 times each to make up for what you did on the short links.
From what they told me is when setting up the Gohbee pitch statically (with original link settings), you may be getting +9 / -9, but in flight it appears to be something like +7 / -11. So, by resetting those links, the helicopter can still be set statically at +9 / -9, but acts like it has +9 / -9 now. I think that there is some slight slop in the system and when the blades are at full pitch and pulling hard that the head may not be going to full pitch but when inverted the pulling of the blades goes with the control system and gives extra pitch. By changing the link lengths, this seems to help. I have mine set at +9 / -9 and it seems to work better now, although climb out is still a little less than I want so I may go to +10 / -10 and give that a shot.
Gary

[Y@nkee]

gaanel
Seems to me that you have eksact the same prob, i did go over all links in the head to get a static linear pitch, i can get -11/+11 , but as you experiensed i also get the feeling that it dosent have enough positive pitch.
The factory lenghts gave me about -5/+13
i set up my linklenghts so that the washout mixerarms is level at 0 degrees pitch.
This was without following intructions for it, i after that found linklengts in a post here on HF (or maybe it was on gohbee site)and checked mine to those, and my links do got the right lenghts according to that.
As you say it flies like it should have +7/-11
Could you measure your linkages and post them?
Hehe maybe i should reset the links back to factorylenghts and it would fly like i want it to.

[gaanel]

Hello,
I measured the links.
Short link is 30.20mm from ball centerline to ball centerline.
Or 1.17mm gap width between the plastic links.
Longer lin is 63.18mm from ball centerline to ball centerlline.
Or 23.50 gap width between the plastic links.

I have not checked out the geometry, but I have a feeling that the control system does not respond symmetrically for positive and negative pitch. I was thinking of mocking the system up on my CAD package and actuate it through there and see what sort of response I get. I will let you know what I come out with.
Gary

[Y@nkee]

Hi
I checked my links, my double link is the same lenght as yours, but the long link on mine is about 2 mm longer than on yours .
Mine is set up to have 0 degrees when the senter of the pitcharm is at the mark for 0 degrees on the frame.

the sesaw mixerarm (from flybar to ball for doublelink) is level when at 0 degrees.

All you other stinger pilots, how do you set up your head staticaly?
What are your lenghts of the links in the head?

[flyinfool]

I'll have to do some measuring, I've never measured anything.
I normally just work my way up from the servos setting everything for 90's and parallel, and what ever the links come out to is where they are.

[Y@nkee]

That was what i did to mine Flyinfool.
But its so wierd, when just looking at the blades it looks like it should have plenty of pitch both ways, but as gaanel says it flies like it should have +7/-11

and as i said about my friends chopper, i measured it to -4/+15 degrees and the engine turns it at full positive pitch with no problem.
I guess with his settings it flies like it should have -9/+9.

I shure could do that , but i would like to get it flying right with a "normal " pitch setting on the head.
Cant understand why it does this when i measure the pitch to be ok.

what could cause this to change when the rotor is turning?
:dontknow Wierd