Help with Raptor 50

[helijohn]

Ok, tail output shaft wasnt the problem.

So now it's back to the drawing board and start over. I assume the tail control rod is nice and free and you are happy with the tail assembly and it turns freely too.

When you spool it up how does the tail rotor come in, is it smooth or jerky and erratic like it is trying to catch up with speed??

Is the clutch fine and healthy?

Tail belt running nicely in the boom?

[glenflyer]

Did you look and see that there was a half twist on belt and not a full turn ?

[Rob99]

Fitted new engine and the problem is still there. Running out of options. Could be the model itself is just too old and needs replacing. Lets face it i have enough parts now!!!

So will be on the hunt for a new 50 / 600 size replacement . Probably flybarless as my X50 still uses a flybar.

[electricsceadu]

because a model is old it doesn't mean it needs replacing
you need to go back to basics with the model
check all the bearings
check that no shafts are bent (including any new that have been fitted)
make sure everything is still tight on the model, ehat screw that doesn't quite tight could be 3 or 4 and the frames are loose
recheck all the alignment of the clutch/engine
ensure the tail is assembled correctly
check the belt and gears
make sure all the electrical connections are good
the rx battery is in good condition
recheck the whole set up in the radio

the model can and will fly, it is just a case of finding what is causing the tail wag

[helijohn]

because a model is old it doesn't mean it needs replacing

I totally agree especially as it is a Raptor; they are built like a tank and should last forever.

Is the problem still that the tail is letting go or are we looking for vibration? Is there another gyro combo you can try?

Tell me about the clutch; did you check it out with the engine out. Do you have a header tank and if so have you been able to note any frothing in it or the main tank?

[trillian]

When I see tail issues, especially like you have described, the engine is the LAST thing I think about. The first things are the mechanical movement of all the linkage and tail pitch slider etc. Then the electronic stuff. Since you went through most of the logical things I'll mention something because this was a puzzler for a while; Someone at one of the clubs I fly at had an occasional kick from the tail, it would be fine and then just kick a bit at random but it seemed to do it more in turns for some reason. We tried all the usual suspects, even swapping out the gyro (this was also a GY401) and servo. And what the cause turned out to be was a chaffed wire on one of the other servos and it was able to short momentarity which would bring down the voltage of the entire RX power rail. So I'd check all the wires to all servos and where the power is connected to the RX.

Vibrations usually cause drifts, not big swings. If it did the exact same thing even when you had a completely different gyro on it I would really think, based on that, it's not a vibration issue. Because although two completely different gyros may both be affected if the vibes are bad enough, surely they would not react exactly the same.

[Tripler]

I to believe its a problem with wiring or servo connections, raptors are quite basic helis mechanically, I wouldn't give up on it,,
I'd even strip it right down and rebuild it to the book, checking everything is in tip top condition, bearings etc,
Raptors are a great hacking around heli, I have a Titan se had it for years and still love flying it,

[electricsceadu]

i'll agree that the rappy is bullet proof
i've seen a 30 a few years ago fly perfectly will collapsed mainshaft bearings

[Tripler]

i'll agree that the rappy is bullet proof
i've seen a 30 a few years ago fly perfectly will collapsed mainshaft bearings

Funny you should say that,,
I happened to check the bearings on my main shaft the other week and they were totally *******, must have been like it for at least 2 years
£3 each from midland, and £1.25 from local bearing supplier

[Rob99]

Thanks to everyone for the posts.

I have already stripped the whole thing down and replaced the main bearings. The issue is at half throttle there is an increase in vibration and increasing to 3/4 throttle causes the tail to shake. This increase in vibration is due to the tail blades going out of tracking. I have relaced the tail hub, output shaft, bearings and casing. There is no significant movement from the blade grips and i have changed th pastic blades for carbon.

If i remove the tail blades and run wih head loaders there is no real issue with vibration and i can run the engine to full speed holding onto the tail. I have tried a 401 and Align gyros and both the same, changed all connector cables and replaced the receiver. I know it is going to be something simple but cant find it at the moment.

[electricsceadu]

have you balanced the tail blades?

[Tripler]

Is the plastic main tail belt drive gear warped or distorted slightly from over tightening the bolt on the main shaft, worth a look,,

[Rob99]

Must admit never had to balance tail blades before and the problem is exactly the same with two different sets, one plastic the other carbon so dismissed this as the problem. The tail belt has only the half twist and the tail pulley looks fine. I will take the whole thing apart and rebuild it to see if i can find any problems.

Tail pulley seems fine and have checked the clutch. Again same problems occur with both engines and both gyros. The only worn part i know of is the starter one way bearing which does not always engage but do not think this would cause the problems.

My reasonong behind looking for a replacement model is due to the fact that it is becoming uneconomical to keep spending money on parts that do not rectify the problem. Noel Cross flew the Raptor a couple of years ago on a lesson and although it flies circuts nno problem, it nearly threw itself apart when he tried to loop it.

[electricsceadu]

did noel give any advice to what could have been wrong at the time?
as noel knows raptors inside out

[helijohn]

There is no significant movement from the blade grips and i have changed th pastic blades for carbon.

So the blade grips are the original ones!! They have not been changed??