Need Help: Vibration, Head Speed, and Collective Pitch

[misato]

I have already tried my best... still no luck on sorting out the vibe...

I have balanced everything... Blades, pitch (tracking ok now), made sure all screws and bolts tight, etc... replaced the gyro...

But anyway... I'll keep trying.

I have a few suspects though...

The main drive gear... there's some significant wobble in it. will this cause a vibe..?

The main shaft ball bearing... there's some little microscopic horizontal play on it. Took out the whole rotor head assembly and let it spin. It has some very small vibe in it, like its some sort of bent in the microscopic scale. Putting on the whole rotor assembly and putting in the paddles and the blades, is this vibe amplified...?

Its unforgiving... but i'm not ready to give up yet... the cost of my repairs so far have reached the price of a new kit... hehehehe

I'll try replacing the bearings... if still no luck, then I'll get a new kit.

If your changing the bearings.. i would suggest you buy the Metal Main bearing block. New kits unless the SE still don't come with these.

http://shop.rotor.com.sg/show-detail.asp?prodid={E049F2C6-4D4E-4784-A010-10133AB5CE9C}&pn=1

If you notice some play on the main shaft, do ensure that shaft collars are leveled and holding the main shaft sufficiently with limited up/down movement.

The main gear naturally has some wobble to it but it should not look like its going to spin out balance anything soon. The contact between the main gear and the motor pinion should have a paper width gap allowance between them. This gap will help to deal with the wobbling free play of the main gear better.

While this might be common sense.... but have you oil/grease those parts that constantly moving? Bearings, shafts, belts etc... sure love some good lubrication to work smoothly.

[iceman_215]

If your changing the bearings.. i would suggest you buy the Metal Main bearing block. New kits unless the SE still don't come with these.

http://shop.rotor.com.sg/show-detail.asp?prodid={E049F2C6-4D4E-4784-A010-10133AB5CE9C}&pn=1

If you notice some play on the main shaft, do ensure that shaft collars are leveled and holding the main shaft sufficiently with limited up/down movement.

The main gear naturally has some wobble to it but it should not look like its going to spin out balance anything soon. The contact between the main gear and the motor pinion should have a paper width gap allowance between them. This gap will help to deal with the wobbling free play of the main gear better.

While this might be common sense.... but have you oil/grease those parts that constantly moving? Bearings, shafts, belts etc... sure love some good lubrication to work smoothly.

Thanks Bro!

I'm going to get the metal bearing block.
Its a good thing LHS are very accessible. So we can just pop in the shop pick up some parts and good to go.

I have the main shaft collar secured to minimize vertical play as much as possible.

I also have the main gear to pinion, and the tail gear to tail drive gear meshes to optimum as recommended by most forums I have read.

Also oiled and greased the necessary parts.

hmmm....

I hope for the last time all goes well... hehehe...

Just making use of all my downtimes practicing with the SIM...
No charge for crashing... and the machine gets back up in no time and in perfect condition... hehehe

[iceman_215]

Finally...

Finally my MT hovers calmly now...

The crazy vibe is gone... and the gyro is holding up "rock solid"... though there's still a very minute vibe during startup but I think its because she's sitting on a training skid. hehe...

Therefore I conclude that each and every pieces of a heli can very well contribute to its performance, even the smallest of the parts.

I'd like to take this opportunity to thank the senior Bro's and everyone who gave very helpful advices and recommendations. Thank you!

Anytime I will encounter issues with heli, I will roughly know what to do.

Thanks lah!

[misato]

Finally my MT hovers calmly now...

The crazy vibe is gone... and the gyro is holding up "rock solid"... though there's still a very minute vibe during startup but I think its because she's sitting on a training skid. hehe...

Therefore I conclude that each and every pieces of a heli can very well contribute to its performance, even the smallest of the parts.

I'd like to take this opportunity to thank the senior Bro's and everyone who gave very helpful advices and recommendations. Thank you!

Anytime I will encounter issues with heli, I will roughly know what to do.

Thanks lah!

Just curious... what did you fixed to make the vibration go away?

[iceman_215]

Just curious... what did you fixed to make the vibration go away?

Just as I suspected it, the main shaft bearing had been damaged a bit during that crash. That minute vibe in the bearing has been amplified as we go up to the rotor head.

Another thing that I have found out is my main rotor blades. I bought this cheap CF blades (no brand name whatsoever), and I believe its been amplifying all the small vibe all over the heli. I'm not so sure, but I tried to balance it properly with a prescribed blade balancer, even had the CG aligned. Now I replaced the my main rotor blades with a good one. I'm not so sure if its fit for a novice, like me, but I was sick and tired of that cheap CF blades. I got a CY Radix 325mm.

Anyway... thank you very much for all your inputs. It has been very helpful.