Hello everyone!

I've got some serious problems with one of my new helicopters. A CopterX 450 Pro v3.

It seems there's no way to get a tail offset in the slider to get rid of it spinning around.

Basically I've already tried Finless Bob's tailmod and flipped the tail to make it trailing edge.

That does seem to help SOME, but not enough. At hover speed it will almost spin around so much that I will need to give full right rudder. Any headspeed above that will cause the helicopter to spin around, unable to stop spinning. Gyro reverse / normal already tried.

What's the easiest fix? Put servo boom mounts and a different servo push rod on the boom? The CopterX 450 pro v3 is the one with the servo on the main frame.

I'm used to helicopters that do not have any offset in the tail, so I'd normally just set it up in rate mode at zero tail pitch. Worked everytime, untill with the CopterX 450 Pro v3 (belt version btw).

Please oh please, if anyone has some insights on this or can point me to whichever thread already goes about this... I'd love to hear!

Regards,
PHMX

What kind of pitch range are you getting on the tail?

I prefer to set up the tail on my heli's as if I was flying rate mode, i.e. with about 8 degrees of pitch to counteract main rotor torque at servo neutral. You normally get that when the pitch arm with the ball link on it is at 90 degrees to the tail boom.

How far out along the servo arm do you have the ball link?

What ATV values are you using for the rudder?

Are you using the tail rotor shaft that came with the kit?

I trust you set the mechanical limits with the gyro, and not by using ATV. I just made up a Lazy Susan to simplify setting up the tail on my 450, and it works a treat

Okey, thanks for the reply. I'll try to answer as good as I can.

I will need to get back on this, as I'm not near my CopterX 450 pro at the moment.

The odd thing is that the arm on the tail is about 90 degrees, but because the servo push rod looked way too long, it was changed for a shorter one. The original one basically wrecked a servo, but I am aware that it's length is different. I'll measure that too when I get back.

Gyro limit is around 95-100, just with the normal CopterX GY240 gyro. The servo end points are 100% in each direction.

This seems to work fine as far as no binding goes in rate mode. I must say that in HH mode it definitely won't steer properly and only is able to stay in a hover at barely the hover speed and in rate mode it's impossible to keep it steady. It will spin.

The ball link on the servo arm is at the third position, that's probably 12mm or so, right? It is 90 degrees though, but I wouldn't have a problem changing that. It's super responsive on the tail now, as far as what does work so far.

I'm indeed using the entire tail kit that comes with the kit, would it make any sense to buy the Align one? ie. longer shaft?

Anyhow I will get back to you, but the 8 degrees of offset against the torque direction does give me a starting point. From what I can tell I'm not getting anywhere near 8 degrees of pitch, when even more is needed from what I understand now.

do you have the gyro direction set correctly?

I have basically the same issue with my copterx pro - I need trim to keep the heli from spinning in rate mode. hh works pretty well, though.

Have you checked the vibration level at the gyro location. most gyros are really sensitive to vibration. PB

another thing to check, is the tail spinning the correct direction? CCW

Yes, I already had changed the gyro direction before and it's definitely the right way now as at a low headspeed I can (almost) hover (when giving a lot of right stick to compensate the torque, also bear in mind I've done the Finless Bob mod). This is barely at hover speed though, so I can't fly this way. Any higher speeds will mean I will lose control and it will spin.

I think I should probably take a closer look at the 8 degrees pitch offset that it apparently needs though.

What the usual tail-pitch range (both ways) you guys have on the Copterx Pro or Align Pro v3?

By the way, thanks for the replies so far.

One other thing to check, I've had the same issue on the clones before, and it turned out to be a) The first time the tail blade holder was slipping and b) One end of the torque tube was turning. Just hold the main blades and see if you can get the tail to turn.

Good Luck

Worked every time, until with the CopterX 450 Pro v3 (belt version btw).

I second checking tail rotation, check your belt direction you may need to flip the twist it is a common set up oversight. with your slider set to the middle and your link arm at 90* you should not have this problem. Make sure the leading edge of your tail blades are turning up towards the canopy and into the main blades. then make sure your gyro and servo setting are right as in reversing. I have done this a few times and scratched my head for awhile then click with the TT ver. you don,t have this problem

Originally Posted by PHMX

What the usual tail-pitch range (both ways) you guys have on the Copterx Pro or Align Pro v3?

On my belt-drive HK450 Pro, I can get almost 45 degrees of tail pitch each way. There's a limit to how much you can use, since the blades will stall at about 45 degrees.

Although the TT version has a longer tail rotor shaft to compensate for the increased width of the tail gearbox, I believe it's still a bit short, which results in the need for something like the Finless Bob grip flip mod if you want to set it up in rate mode, and the pitch range is possibly less. Not sure until I can get my calipers on a TT Pro tail though!

If you're continuing to struggle setting it up, I think you ought to mount it on a Lazy Susan - you can get more done more quickly with no risk of crashing.

On the Lazy Susan, it's amazing to feel just how much thrust there can be from the tail rotor. I held the tail by hand to stop it drifting in one test run, and the gyro duly tried it's best to keep the tail turning. Not a procedure the Health and Safety ploice would approve of though!

Thanks guys, lots of things to double-check for me when I'll get back.

Yeah, the Lazy Susan is a great idea. But previously I had the CopterX 450 pro v3 on a turntable (one you'd normally use to build clay pottery) but it almost ripped the tape off and was in fact able to lift the turntable. Oopsydaisy!

So I'll need to investigate a different kind of Lazy Susan like you're suggesting for sure. I'm not that fearful for a crash though, I've seen it spin around in the air a good couple of times now and the trick is to keep the main rotor blades level through cyclic control.

It takes a bit of practice, but there's not much stress when the heli does a full spin now. Too bad I can't control it properly just yet.

The 45 degrees does give me a pretty good idea where to look as for solving the problem.

Haven't checked whether the tail blades can move independently from the main rotor blades, but I do know that the blades turn inward (which is the right direction knowing my Belt CP v2 and King v3 do the exact same).

I think the offset is key to success here. But I'll report on the progress soon.

Thanks for all the ideas guys!

What 450 Pro version do you have the TT or belt version ?

I've got the belt version v3 of CopterX 450. I got it from Ehirobo.

Can anyone here please confirm if the torque tube version doesn't have this offset issue? I mean it's fine to have an 8 degrees offset on the blades when everything is 90 degrees (servo arm, push rod arm etc.), but it's strange it won't get anywhere near that in my case.

I might shoot some pictures this weekend if I'm able to.

I totally appreciate all the hints or comments on this I can get, so thanks again everyone.

The PRo version really has some design difference from the previous V2 model. Even align has this..
what i did on the TT version was i pushed the shaft out 1mm and increased the shaft flat spot another < an mm but it increased the pitches and made the negative pitching a little bit correct.. made great difference on tail blow off

Originally Posted by PHMX

I've got the belt version v3 of CopterX 450. I got it from Ehirobo.

Can anyone here please confirm if the torque tube version doesn't have this offset issue? I mean it's fine to have an 8 degrees offset on the blades when everything is 90 degrees (servo arm, push rod arm etc.), but it's strange it won't get anywhere near that in my case.

I might shoot some pictures this weekend if I'm able to.

I totally appreciate all the hints or comments on this I can get, so thanks again everyone.

Originally Posted by soneebee

The PRo version really has some design difference from the previous V2 model. Even align has this..
what i did on the TT version was i pushed the shaft out 1mm and increased the shaft flat spot another < an mm but it increased the pitches and made the negative pitching a little bit correct.. made great difference on tail blow off

that does seem to confirm that the problem is the stock tail rotor shaft is too short. I've done the same mods on my belt-drive HK 450 Pro in order to use some Align Sport tail rotor shafts I had, which are about 1mm shorter than the stock HK shaft.