Finally some air time!!

[Joemeredith]

Hey guys, so i took my cpx out yesterday morning, lots of space no rain and only the lightest of breezes. Everything was set up so what was my excuse? Well there wasnt one so i ended up outside in the field with my heli ready to take off!!

Excellent, but what about that horrible horrible tail wag thats kickin up before lift off? Well i thought it was goin to shake the heli apart so i spooled down, rolled a cig and got on my phone. Quick internet search and i found out that gyro gain can affect this, so i found the correct dial on the tx, spooled up till the heli wagged then messed with the dial - hey presto the wag went away (sooo nice when its such an easy fix!).

And i got up, clear space so i could fly woohoo. I 'crashed' about 3 times from no more than 10ft and the blades were pretty much stopped each tome so those times there was no damage, and i got up in the air a few more times. Last one i was up for about 5 mins, i wasnt goong in circits or anythin meaningful but i got 5 mins to play and make a start on what to do, see what its like in the air and how to correct things. But i still couldnt land (figures right) and when i came down to go in (only got the stock 1800 battery at the moment) it came in a bit hard, swashplate isnt level anymore but i think thats a slipped servo arm rather than anything else. Ill be setting it up and spooling up to test at lunch, all things going well i can be in the air again tonight .

Just a couple of questions (which is why i made a thread rather than using the progress update thread). How can i set up the gyro gain so the dial on the tx can be centered? Its the stock tx and i have had to turn the right hand dial (ch5) all the way to the negative sign.
Also there was a constant lazy drift to the left. It wasnt the wind as it was always drifting left regardless of orientation. This meant i constantly had to be holding a little right on the aileron i believe it is (right hand stick) to try and stay still. How can i solve this? An last question: on my copterx head the flybar can spin freely (so the paddles can end up facing the floor) should the flybar be able to twist that way or not?

Thanks guys

[copterboy]

I'd call that a success, so congrats for getting out and the 5min hover and plodding about. It's the only way to start, unless you have very deep pockets or deathwish!!

If you have the stock TX, then you might be stuck with setting the gain that way, unless you can find a way to adjust the gyro gain first, then trim it with the TX. Is there also a gain pot on the gyro?

Sounds like your swash is not level, as giving right AIL input corrects it. Level the swash again, and trim out mechanically (by adjusting servo - swash links) or with the trim switches).

Sounds like your flybar is loose, and no it shouldn't be to move like that. Have the grub screws come loose that stop it from rotating? Or is the a problem with the lugs that hold the flybar seesaw secure in the rotor head?

Hope that helps anyway. I'm just on my way out the door, so sorry I don't have time to explain better. Hope you manage to sort it

[Joemeredith]

Thank you! Yeah i fugured i just need to be as much as possible, so at the moment my cars are takin a back seat while i get a but more comfortable with the heli. That way i can justify spending on some upgrades for it and maybe looking into a haulage project i have always wanted to do for a heli. But thats way down the line for now.

I can only see a 'limit' and 'delay' screw that i could adjust, as i havnt been over the instructions again, guess i really should!! Im not sure what each does, thats why i didnt mess with them in the field. I think it should be ok just using the tx to trim it out, would have just been nice not to have to you know?

Hmm i see what your saying but i had the swash leveled with a leveling tool (got that plus a pitch guage). Though i had to lower the entire swash as it was hitting the head at full throttle when i was setting it up (idle up mode the part around the mainshaft that holds the washouts was hitting the bottom of the main head section). Though i releveld after that, i may have missed a bit at that point though. Ill make sure i have that 100% level before the next flight and see if it solves it. Ill also play a bit with the trim in the air and see if i can get it level

I didnt think ths flybar should be like that. I guess a knock on landing has loosened something up a bit - ill check that at lunch also

Should be helpful enough . Guess ill find out later this afternoon . Cheers!!

Edit:
Just had a quick look at the flybar - must be the grub screws that are loose, plus its just a little bent - great no spare at home so i better see if i can pick one up at lunch

[dauste]

The drifting to the left thing is normal, you just have to correct for it on the sticks in flight as you did. It is caused by the tail rotor thrust pushing the heli along.

[Joemeredith]

Dauste: i had heard that in my travels over the internet, just wasnt sure this was the cause, nice to be able to rule it out now though, something im sure ill learn to deal with.

Not certain i can get running tonight though, things just dont quite look right to me. The tail servo seems to have a mind of its own and will rotate further one way than the other, i think one of the blades is sagging but cant decide if its just the one blade - thus the feathering shaft - or the blade thats at the back - thus the main shaft. There is a larger gap between the head and clamp of one blade than the other. And the movement of the blades doesnt seem right. If its on my desk and i use the control that alters the pitch of the blade (i think the left/right on the right hand stick) then the movement isnt what it should be. Iirc then there should be a range of +/-7 degrees either way but there seems to be about +/-2 degrees either way. Not too certain whats going on there but i didnt have time at lunch to fix it. And really have some car work tonight (restoring an old tamiya for a mate and its been on my desk 2 months now!). So hopefully i can get at least 2 of the cars out of the way quickly tonight leaving my bench free for some work on it tomorrow.

I could go into the LHS tomo as well, but would only have 20 mins there. Do you guys think it would be worth my while to pop in and just question them a bit on its setup and if everything looks ok?

[Tomstoy2]

To test for a bent flybar, pull one blade off, insert the allen wrench and rotate the shaft in a clockwise direction, observe the other blade, any movement and the flybar is bent.

To test the main shaft, pull off both blades and tail blades, spin up the heli, look down from the top, see if it wobbles. Also look at the tail, see if that shaft wobbles.

The swash plate must be centered in idle up, (motor disconnected), after leveling it. This is checked by checking both positive and negative pitch. They should be equal. If you have more positive than negative adjust the ball links shorter, twist all 3 the same ammount until pitch positive and negative are the same,
Reverse procedure if pitch negative is more than positive.

Next, move the blades parallel with the heli, install the pitch gauge again, move the aileron control and see if pitch changes at all when aileron control is moved. It should not.
Unfortunately, this is where the limitations of the stock radio come into play. There is no way to adjust for zero travel.
On a computer radio you would adjust servo travel to ensure the blades stay level when facing parallel with the heli.

In flight, if the tail drifts in one direction constantly, this can be corrected by adjusting the length of the pushrod to give more pitch in that direction.

On take off, it is normal for a heli to lift off with a little sideways movement, but once up out of ground effect, if the heli pulls in one direction, then try shortening one of the swashplate pushrods on the opposite side to achieve level hover.
This is a sign the swashplate is not really level, or something else is not right, like mixing arms.
On the ground, motor disconnected, after adjusting, look at the swashplate again, if it looks like it is not level, then you mixing arms were not adjusted properly.

Flybar is critical. It must be straight, it must be equal length without paddles attached, and must be equal length again after installing paddles.
These too, must be a zero pitch when in indle up mode when the blades are at zero pitch.

Blade balance is critical, as is paddle balance and tail blade balance. All need to be the same.

Tracking the blades is critical, also.

As far as having the lhs checking over your bird, I would only do this if they are well versed and actually heli pilots who fly alot.

Over time, you will develop these skills to where you can do them in your sleep.

[sutty]

How the hell would you know how to set-up a flybarred heli?

[copterboy]

Just for the record Joe, that question is aimed at Tom

Good one Andy

[Tomstoy2]

Bastards!!!!

[Joemeredith]

Hehe, thought it may be - see for me its a sinple answer - cause it all looks like a jumble of parts!!!

Tom: thanks for all that info, a lot to look at and some bits to read up on - cheers just what i need, more homework :p. i think i will take it in, especially as i may be able to get the rest of the week off so ill have time and the weather to want it flying! There is a kid that works at the LHS and he was telling me he flys in competitions and seems to know his stuff, plus they always have a heli of some sort getting looked at on the bench so it should be fine. I think having someone walk me through the process would also be a big bonus and a huge help so i can get things organised in my head a little more.

None of this would be so bad if i could land the darn thing! But then i have always struggled to land even with the co-ax helis . Got some blade parts coming for my axion though (hopin i can slowly convert it to an msrx) so that should be flyable in a day or two at least and i can practice a bit with that

[jperkosk]

You need to learn to land, Joe. Bring it into the steady tail-in hover 5cm from the ground first a then decisively bring it down (without slamming). I either hit TH at this point or just pull the stick down gently. I normally switch back to normal mode on the landing approach about 1m from the ground, unless it's very windy and I need to slam it down harder.

As they say, takeoffs are optional, but landings are obligatory

[Joemeredith]

Yeah this crash landing every time is getting a little tricky on the repairs!!

Problem is the micro i fly is nearly impossible to dial in, thus i cant get it to hover stabley and give me the chance to land. So little to no practice there. And the belt just hasnt been in the air enough for me to get to that point yet. The best clear air time i have had wasthe other day and the excitement of being in the air and slight confusion of having 4 direction controls (throttle, cyclic, collective and the other one (ill learn i promise!)) instead of two (cars - throttle and steering) stopped me from being in a good position to land.

Really wish i could not be in work right now, wanna get the belt sorted and in the air again! This time ill be a little slower and more steady when i get in the air

[jperkosk]

I've just started a small project of teaching a new club member to hover a heli. He must be nuts trusting my instructions , but what I'm telling him right now is to scoot around on the concrete, training gear on, and manage collective to never have more than 1 ball of the TG leave the ground. He's gone through a few batteries with no crash and is sending me emails about when I'm back from this trip, swearing he's ready for the next step

We are only about 5 heli guys there, and the guru has been absent from the hobby since December, he has some mundane unimportant life problems interfering with the hobby, something about wife catching him red handed with the lover, kicking him out of the house and suing for divorce, house, and custody , so someone has to cover for him

[Joemeredith]

I have read thats a good way to get going, just skim over a concrete area and get used to those movements first. Something i always want to try but im usually by myself when im flying - no one to tell me off for just going up which is just oh so tempting!! And i like the feeling of having a load of space, when im that close to the ground i feel like the heli will just tip over and the blades will smash up.

Hmm sounds like he is having a good time right now :s. but good on you for taking his place while he is out!

[Luke Warmwater]

Originally Posted by jperkosk

wife catching him red handed with the lover,

Schoolboy error!


When my ex-wife accused me of adultery with her friend (actually untrue...she got her friend to lie for her etc......man they must have both hated me....), I took great pleasure in correcting her by telling her, "Right crime, wrong person!" The look on her face was priceless...lol.