Yet another newbie to this forum

[Rctintin]

Hi all, just getting back into heli's after aprox 13 year absence. At that time i had a hirobo shuttle with an OS 32 SX. I got to the point of stall turns and some not so round loops!
A mortgage and marage followed, so with the need to work on the house etc, the heli and planks were sold
Now i'm back, and with the help of the web, and lots of reading, i have got my self a T-Rex450 pro and DX7, along with a cellpro 10S charger.
All built up and now completed 8 flights
The hardest bit is learning the gyro! My old futaba one had a motor in it spinning away!!
It hovers very well in rate mode, but as soon as i switch to HH (on the ground) the tail trys to drive hard one way. Any ideas please?
I live in Gloucester and looked on the net for a local Heli club without success. If there's any one local to me that flys in a club,i would like to hear from them.
Cheers for now, Rob

[JeromeF]

Are you sure that the gyro doesn't want to yaw one direction when in Rate mode and not HH as mentioned?

There is a club in Gloucester, the link is here, I don't go there but haven't heard any negative comments about it.

Welcome to the forum... Always nice to have more locals, I'm from Gloucestershire too...

[terryk2000]

Good choice of equipment...Welcome to the mad house Rob

Cheers
Terry

[Rctintin]

Deffo in rate mode that it flys ok. If i sit her on the ground with the head spinning just below lift off and switch to HH the tail drives hard to one side. I have gear assigned to gear in DX7, and used the end points to set gyro to 32/75.

[robgt]

Sounds like your gyro sensing is reversed.
I'm guessing it is the GP750 gyro if you bought a combo 450 pro?
If so, switch NOR to REV, or vice-versa and try again.

Cheers,
Rob

[JeromeF]

75 is your gain on End Points? Try lowering it... IIRC mine is set to 38 - complete stock 450 Pro.

Have you followed through the setup as per the manuals instructions?

[Rctintin]

Thanks for your input, will look at it again. I do have the 750 as stock with the pro. I have watched finnless bob's video as well, so i will check again how i have done it.
On a different subject, i have a real flight 3.5 sim, and it is megga lively trying to hover on there. Is it better to use my DX7 with expo rather than the RF Tx? I have asked this question on the sim forum page, but no replys.
Thanks for your help guys, Rob.

[unwind-protect]

Have you got any tail trim applied? Did you have any applied when you last bound the rx?

Both of these can upset the gyro's understanding of what 'centre rudder' is. You can compensate for this in rate mode with mechanical setup, but not heading hold.

[Rctintin]

No trim when rx was bound. I needed a couple of right clicks of trim in rate mode, so landed and moved ball link one turn. This then needed a couple of clicks left. Is it ok to fit link half turn i.e. wrong way on ball?
With trim centre, HH still locks hard one way. I have no tail wag, so guess gain is some where near.

[Rctintin]

Sounds like your gyro sensing is reversed.
I'm guessing it is the GP750 gyro if you bought a combo 450 pro?
If so, switch NOR to REV, or vice-versa and try again.

Cheers,
Rob

Tried that tonight,and all that happened was it just altered HH and rate mode to position 0 or 1 on the gear switch. Still same thing as before. With Heli on ground, this time without head spinning, if i switched to HH the servo would pull hard to one side. Put her back to rate and servo centered again.

[rchelispares]

if you hold the rudder in a bit on the transmitter does the tail blades angle continue to move without moving the rudder stick further and then stop once you release the rudder stick?

EDIT: in heading hold mode for above

[JeromeF]

No trim when rx was bound. I needed a couple of right clicks of trim in rate mode, so landed and moved ball link one turn. This then needed a couple of clicks left. Is it ok to fit link half turn i.e. wrong way on ball?
With trim centre, HH still locks hard one way. I have no tail wag, so guess gain is some where near.

The balls need to go onto the link with the 'A' on the link facing away from the ball. You idealy don't want any trim at all - but I guess you are getting a problem with push rod length?

Tried that tonight,and all that happened was it just altered HH and rate mode to position 0 or 1 on the gear switch. Still same thing as before. With Heli on ground, this time without head spinning, if i switched to HH the servo would pull hard to one side. Put her back to rate and servo centered again.

Are you powering up the heli with HH enabled before it gets power, so it initializes? If so, when it is on the ground and you yaw the heli by hand does the tail move smoothly and once stopped, does it drift?

[unwind-protect]

With Heli on ground, this time without head spinning, if i switched to HH the servo would pull hard to one side. Put her back to rate and servo centered again.

If the sensor is working correctly (gyro initialized properly, etc), then it still sounds like the gyro is confused about the correct centre signal. Usually when a gyro starts up, it samples the signal from the receiver and uses the current position as the "centre" position; all subsequent commands are with reference to this. As the gyro is usually initializing while the receiver is still trying to find the transmitter (and so putting out servo failsafe positions), any mismatch between the failsafe and real centre will cause the servo to slew without any stick input. Rebinding will reset the failsafe values to the current control positions.

[acwman]

Deffo in rate mode that it flys ok. If i sit her on the ground with the head spinning just below lift off and switch to HH the tail drives hard to one side. I have gear assigned to gear in DX7, and used the end points to set gyro to 32/75.

You mention that it does fly ok in rate mode.. therefore everything is sensing correctly.

You mention that it tries to spin just below lift off in heading hold. In Heading hold, you will find that it may tend to do that.. but once in the air it should hold straight.

also your gyro settings 32/75 n your dx7
If the hh is 75.. you may want to bring that down to around 40.. and bring it up to a point that does not wag.

[Rctintin]

Thanks for all your input guys, i will go back to the start and re bind, with no trim and see how it goes.
I was under the assumption that rate mode was between 0-50 and HH was 51-100? If that is the case, why would you drop HH to lower than 51?
Sorry for all the questions, i'm finding the gyro the hardest bit to get used to! Up to 15 flights now and loving the little pro, just spending time hovering and turning sideways eather side of me.
Cheers, Rob