Vibrations

[Rob O]

That's great mate , glad to here that you have got her sorted . Rob

[cambs flyer]

Thank you Rob.

This has been a huge learning curve, knowing the software can effect and cause hardware like conditions when everything is by the book.

I'm please to say the least that my 450 is back to her ballistic self once more.

[Rob O]

It certainly is Wayne , i dont think i would have been looking for that problem in the Tranny settings , it certainly sounded like a problem in the Heli . Still i guess it is all a learning curve , a very long one at times lol . Rob

[Sao]

WTf!? How can tranny settings effect vibrations in the heli!?

[cambs flyer]

LOL, well it did and I had Mike here last night to witness it.

[Sao]

It appears scottie was wrong


<scottish> Ye can re-write the laws of physics! </scottish>

[cambs flyer]

OK this saga is going from bad to worse, last night via torch light Mike & I flew my 450 and he agreed she flew perfectly.

Today being the start of some serious test flights just to be certain of her flight worthiness, started bad, a slight bit of vibration then she flew OK, the tail box seemed to vibrate quite fast then the 450 went nose in all on its own, so I landed her.

The rudder did seem somewhat loose and as the HH rate was at 91%, before the tail was rock solid, however on my third batt and this is what worried me the most she went totally out of control, I dropped the throttle and she continued to do the dance of death for at least five seconds at just over half throttle then she finally stopped.

Now I have completely no confidence with her safety, the Gyro & tail servo have been changed since she lost it high up a few weeks back and the only thing thats been the same is the red ESC which gets rather hot, and much hotter then my previous ESC, but I'm beginning to wonder if the TX is faulty, Mike's helping me out with this but I'd value others opinion as well.

Since changing over the ESC & Motor I've had more non-fault crashes then a little, to fly her now is like flying on a razors edge as I never know when she'll lose it, plus I'm now worried about using the DX6i with my Trex 500 as I'd be ****ed off in the extreme if the same happened to her.

After the last expense its gonna be a few weeks until I can afford to patch her up again as it cost £60 last week and quite a bit before that, right now it's costing more to keep the 450 flying then running our car, whereas before I changed the motor and ESC (as the old motor burnt out, and the new motor didn't have the same Banana plugs as the original ESC so I changed the spare ESC for the fact it had the same banana plugs for convenience,) I can't remember the last crash I'd had.

Any ideas chaps, thanks.

[trebor27]

Sorry to hear of your grief bud... I finally managed to fix my vibration problem on my protech Zoom450, I THINK it was the tail rotor that was out of balance! It was a VERY bad vibration!

Things I would investigate, sorry if you've checked this already.... I'm list everything I can think of no matter how simple, so don't be insulted
1. Check the belt tension
2. Remove tail boom, and remove tail box. Check belt down full length for any damage/missing teeth/fraying at edges. Replace it to be sure if there is ANY doubt....
3. Remove tail belt drive from heli, I'd probably replace the drive shaft, just to be sure, with a new pulley, in case the pulley is slipping on the shaft....
4. Disassemble the tail box and replace tail shaft and pulley for new, again in case the pulley is slipping on the shaft...
5. Reassemble tail shaft and tail hub INCLUDING tail rotors OUTSIDE the tail box, put it on a high point balancer, mine was WAY out for some strange reason...

I'd start there mate! I'd do a range check with your radio before you fly next, it might show up any problems if something has gone dodgy in the tx/rx combo! Unplug your motor bullet connectors first!

If you don't have a high-point balancer then let me know I can bring mine up if you want. I'm only down the road mate!

I know EXACTLY hwo you feel! I felt exactly the same until this afternoon, first flight my my Protech in over 2 months and it was FINALLY sorted!!!!!!

Chin-Up! You'll get it sorted in time!

Rob

[cambs flyer]

Thank you Rob your most kind.

Now you mention it while looking at the tail rotas you know when the main blades are out and you adjust the bale adjusters so there in perfect alignment with one another, well the rear blades looked out of balance with that double sided blur you see on the main rotas so clearly, plus the rear box was vibrating in very fast but small motions, but the main body seemed OK while in flight.

I'll print off what you've kindly offered and absorb it tomorrow as I'm a bit spent right now.

Thanks again Bro.

[trebor27]

No prob mate! My tail was shaking like crazy up and down.... It was bad enough the canopy was makign a right din as it was rattelign liek crazy, actualyl wore the canopy mountign holes oval in 30 seconds! The main shaft and head was a bit of a blur too! Mine was that bad!
But the tail seemed to be bluring vertically, that's what made me suspect something tail related! But I wasn't sure and I doubted myself every step......

Just remember, bad vibes and really screw with your gyro too.....

Wonder if you could have a slightly warped tail blade? So your "tracking" for the tail rotor is off... I don't know if that's even possible, but you never know! Anyone else very seen something like that?

I'm learning myself mate! This is the list of stuff I replaced trying to sort the Protech, so you can guess how hacked off I was! Just keep at it mate! Don't let it beat you and you'll be having fun again soon!
1x main shaft
main bearings
main blades
main gear
tail-drive pully shaft (main gear end)
Pulley
Tail drive bearings
Tail shaft
Pulley
Tail blades
Tail blade grips
Tail pitch slider
Tail shaft bearings

It's finally sorted!!!! Dunno how much of that was pointless, I suspect most of it, but aint going back now!
Rob

[unwind-protect]

I'm afraid I've no idea what's causing it; I usually just try running the heli with bits removed until I diagnose where the vibration's coming from (doesn't always work :-( ). My recent problems have all come from a badly machined tail rotor hub, but I'd hope Align's QC is better than Sonix's.

As you say this has all been happening since you replaced the motor and esc, I have a motor and esc that's currently surplus to requirements if it's any use to you for elimination porpoises.

[cambs flyer]

No thank you, that's valuable information bud.

I'm wondering, as I upgraded the gearbox, it still has the plastic slider and blade holders which came off another heli, possibly buying the rest to kit out the rear plus new blades might be a good thing.

I'm almost 100% sure its the rear end causing all these probs' as when I hold the 450 the main shaft speeds up without any vibration blurring, again while reving up she shakes but once in the air shes smooth only very dangerous to do anything apart from ground effect flight heights.

But the fact she went totally out of control and even with the throttle cut she still powered on has got my quite concerned.

Many thanks again mate, I've loads to chew over with this one for sure.

[cambs flyer]

I'm afraid I've no idea what's causing it; I usually just try running the heli with bits removed until I diagnose where the vibration's coming from (doesn't always work :-( ). My recent problems have all come from a badly machined tail rotor hub, but I'd hope Align's QC is better than Sonix's.

As you say this has all been happening since you replaced the motor and esc, I have a motor and esc that's currently surplus to requirements if it's any use to you for elimination porpoises.

Thank you mate, your most kind, TBH at this point I'll be willing to try anything.

Please PM me what you'd like for them mate, but you mentioning a badly machined tail rota hub..... The more I think about it the more I think this is where the issue lies, not that I'm ruling out the other ideas one bit, but possibly changing over everything so its all alloy might solve it, but it'll be a few weeks before my Heli fund can finance that, but yes as said before small vibrations picked up by the Gyro will make them do crazy stuff while in flight.