second test flight

[deepak]

Hi Folks
Well after chewing up a main gear cause the power jazz was not set up right. I got the esc fixed over a phone call with Bob at Esprit ,went to try it out gain this afternoon. Spooled up really nicely but got some serious tail wag just before lift off. Turned the gyro sensitivity up to 40% and she just hung on the rotor blades.
Got real excited and took of to the local schoolyard to give it another fly but with lots more room.
She flew real nice. Tail rotor much to sensitive but sweet flying.
I hit stunt one and she fell out out of the sky. About 5' . Enough to destroy the tail rotor drive gear. That sucked as it ended the evening flight.
After looking at what happens when I hit stunt one ( at half stick the pitch drops) I realized why it dropped out of the sky.
Can some one tell me what I should do to prevent this happening again.
I'm using the spektrum DX 7 series stuff. Kindly let me know.
Thanks
Deepak

[OICU812]

I don't understand are your pitch curves linear from 0-100? Are your pitch ranges the same pitch wise + and - in all flight modes? Sounds to me like your Idle 1 had been programmed with a different pitch curve or what is the deal here? I am assuming you went through all of this with a fine tooth comb pre flight on bench to confirm everything worked as it should yes???

In each flight mode, normal, idle 1 and idle 2 your pitch curves should remain the same and should be linear from 0-100%, you should see the same exact amount of pitch on each mode. Furthermore ensure your throttle curves are proper as well of course, for example maybe your normal mode that you do no fly in is 0-100 linear, and your idle one might be for example 70% flat curve and your idle 2 might be 80% flat curve so that there is no drop of power throughout the movement and range of the throttle/collective stick.

[BruceW]

Here is a screen shot from page 19 in the manual where it shows that the pitch curves above mid stick should match all flight modes. When you go from normal to idle 1 or 2 there should be no pitch change. This way your helicopter won't jump. You should also setup your throttle curves appropriately for each of the flight modes. Also remember that if you trimmed your helicopter in normal mode, you will need to transfer those trim settings to each of the flight modes.

http://www.helifreak.com/attachment.php?attachmentid=43548&stc=1&d=1206683661

EDIT: Posted before I saw Shawn's response but this is basically saying the same thing as him. You need to check everything on the bench before you fly. While your at it, you might want to make sure your cyclic range is properly setup in the swash menu as well (aileron & elevator) to give about 6 degrees.

[wlfk]

Switch to 'idle' whilst still on the ground.

Normal mode is nice when you're learning because it makes the collective less sensitive. It's hard to descend if you get too much altitude though. Arguably you can kill the motor quickly by taking the stick all the way down; in practice it's better to hit throttle-hold because you avoid slamming the helicopter to the ground.

Most people just use 'normal' to spool up - if they don't have a good soft-start. It's a good idea to get used to flying in 'idle' all the time as soon as you have hovering under your belt though, because otherwise, sooner or later you'll try flying upside down and the rotors will stop.

K

[OICU812]

OK lets be 100% clear on something here as well, while we are at it. On any Kontronik PowerJazz or Jazz esc of any size for this matter you can "NOT" fly in normal mode with linear throttel curve, the motor will surge "violently" and can easily cause a crash, that Jazz escs needs a flat curve PERIOD. It is ok to initially start in normal for the first two seconds than transition into Idle 1 or Idle 2 "VERY" quickly but can absolutely become tragic if you attempt to decend or land in normal mode with a linear throttle curve.

[OICU812]

I also argued this in a Align forum each to their own but I have to say I am a "FIRM" believer in setting up each flight mode with the same exact pitch range. I certainly have never seen or felt a benifit even to a beginner to have a non linear pitch curve. If the Pitch curves are same in each mode and are linear it is "MUCH" easier for a new pilot to get a feel for true collective management and is much easier to transition into mild 3D moves as they progress, my two bits! :smokin:

[deepak]

Hi Folks,
I did set up the transmitter and checked the pitch ranges as per the instruction manual.
It flew very well in normal mode. I set the throttle curve straight 80% thereabouts in stunt one and 100% in stunt two. I run the same + and - as per instructions in these modes. I the normal mode I have it set up like the instructions -2.5 to +11. Stunt one and two -10 through +11
How does one set up stunt one and two without having the pitch drop.
Example: f I'm hovering at half stick, I hit the stunt button she drops, I dot think that should happen. It should either stay right where its at or go higher because of higher head speed. Is this not so?
Kindly let me know.

[wlfk]

Find the hover-point in normal mode; memorise it; land then flick to idle with throttle hold on. Look and see whether the collective changes on the model and which direction.

K

[deepak]

Find the hover-point in normal mode; memorise it; land then flick to idle with throttle hold on. Look and see whether the collective changes on the model and which direction.

K
Hi
At half stick in normal mode is the hover point.
If I flick the switch . It drops a whole lot at least 1/2" looking at the swash plate
In stunt 2 the same applies.
I get a whole lot more negative pitch in these modes though.
Thanks
D

[OICU812]

So what is your pitch curve for throttle hold mode?? If you flip it into TH hold and the pitch as you explain goes down by what you estimate t be a half inch which is several degrees of pitch it is obviously in your tx yes??? Have you read the manual for your tx and fully understand how to use this, if not you should not be even flying the heli with it imho....


Sounds to me that this is in your radio, if you have anyone near you that understands the DX7 very well that can help you go through this? The DX7 is pretty straight forward, but no offense sounds like you are very new to this hobby in general...? If you can get some local hands on help that might point out something you are not seeing, if no help avaialable we'll keep trying to help ya here no problem....But surely does just sound like you got something weird with your programming is all.

I'm going to clam it now on the pitch thing as some of you know I really disagree with this method of setting up pitches....

[Big Fil]

I'll agree here with Shawn on the pitch settings being the same in all your modes. Only time in my opinion you should run different ones is if you know exactly what it is your doing and the way the heli will react when you switch modes.

[deepak]

Hi Folks
OK, got the pitch issues sorted out in the transmitter.
Working well now. However, I don't know how to tame the tail rotor. Its much to sensitive.
Do you guys have a word of advice here for me please. I'm using the jr 7703d with the 8900 servo. Iwish to have the tail a lot more predictable.
Slowly getting the macine sorted out. Your help is always appreciated.
Thanks
Deepak

[LITHIUMSTATIC]

Hi Folks
OK, got the pitch issues sorted out in the transmitter.
Working well now. However, I don't know how to tame the tail rotor. Its much to sensitive.
Do you guys have a word of advice here for me please. I'm using the jr 7703d with the 8900 servo. Iwish to have the tail a lot more predictable.
Slowly getting the macine sorted out. Your help is always appreciated.
Thanks
Deepak

turn down the travel limits on your rudder in your radio. This will slow the tail down.

[OICU812]

turn down the travel limits on your rudder in your radio. This will slow the tail down.


Turning down enpoints slows the piro rate, if you feel the tail moves abrupt to easily at center you need to add + expo on the tr channel , for example add in 20% to start to not see the slightest command.

[LITHIUMSTATIC]

Turning down enpoints slows the piro rate, if you feel the tail moves abrupt to easily at center you need to add + expo on the tr channel , for example add in 20% to start to not see the slightest command.

HHHHuummmmm........ I've never thought of doing it that way. You will be able to have your piro rate at the speed you desire but still be less sensative mid stick. Cool :noteworthy

[BruceW]

I have about 15% expo on my rudder but my endpoints are at 135 for the Spartan DS760 on the L500. The GY401 on my T450 runs endpoints of 105 that gives about the same piro rate.

One trick maneuver I like doing with the L500 is to take it up high, set it up into a straight down tail slide, flick the gear channel (use gear instead of gyro mode in radio) to set the gyro into rate mode, and give it full left rudder (goes with torque) and watch the heli spin at about 5-10 revs/secs (insane) all the way down.

In HH mode, the piro rate is controlled by endpoints but in rate mode it just goes to the end of the adjusted travel which lets it spin at max possible rate.

[deepak]

Turning down enpoints slows the piro rate, if you feel the tail moves abrupt to easily at center you need to add + expo on the tr channel , for example add in 20% to start to not see the slightest command.
Hi
Morning. Will try your suggestion this afternoon and get back to you.
Thanks again