Logo 500se Extreme vibration

[G Steyn]

I am out of ideas....

I have a Logo 500se with mini v-bar, that hovers perfect (60% throtle), vibrationless, no vibration logged on the vbar.

Scorpion 4025 motor, 15t pinion, 6s 5000mah packs

As soon as Idle1 is flipped(80% throttle), there is an audible vibration, sounding like a tail vibration, but visually nothing vibrates on the heli. The V-bar gives me a Code 62 Extreme vibration on the log.

Main and tail blades tracks perfect, and the vertical tail fin is still.

As soon as the vibration starts the heli rolls to the left from a stationary hover.

I'm out of ideas.....
I've checked the following:
- Balanced main gear.
- Checked for smooth sliding tail guide, and tail rod.
- Replaced tail servo.
- Disassembled thrust bearings in tail and head, greased, and checked if bearings are correctly installed.
- Spin tail grip in tail hub to make sure it rotates freely.
- Moved tail clamp forward to make sure it doesn't collapse tail boom.
- Adjust tail belt tention from frame.
- Check if carbon plates are 100% parallel.
- Checked to make sure tail bearings doesn't have side thrust, installed extra spacer to make sure bearing "cage" is parallel at 22.2mm.
- Replaced tail shaft.
- Prop balance checked tail hub.
- Moved tail guide bearing to forward position to eliminate pressure on belt.
- Loosened tail belt tension.
- Checked tail guide pulleys in frame for smooth running, and bearings.
- Checked tail blade direction, and make sure grips are leading edge.
- Removed belt, and spun tail only to check for any resistance.
- Rotate main blades, heli turns 4 turns easily with all rotating components connected.
- Installed Mini V-bar with tape, then vibration plate, then tape again.
- Dynamically balanced main and tail blades up to 0.01g.

I'm yet to do a vibration analysis on the heli.

Any ideas as to what I can check???

[thefrog]

I had the exact same issue. It relates to head speed apparently - if you keep it under 2050 or so it will be ok. As soon as I bumped up the head speed much past 2100 mine had this issue. I replaced everything in the tail, some parts more than once. I tried tight belt, loose belt, more shims, fewer shims, whatever I could think of. The only work around I ever had was to use an external governor and turn the gov gain very low; but I could never fix it (10/11 months). Vibe analysis showed lateral vibe spikes from the tail.

Eventually on my first bad crash (unrelated) I just stripped the heli of electronics and threw the rest away. Goodbye Mikado.

There are a number of threads on this topic and many of the fixes differ from person to person - so no magic formula.

[Lompma]

I too had the same problem with the 500SE. I did all the things you did even tried different blades. Only thing I did not try was cutting down a 30mm 600 boom and use the 600 cf tail case. I read some people thought the 25mm boom was to small making it harder to get he tail case together right. I do have a 500 with the stock plastic tail case and the vibe are minimal. I would never consider upgrading to the cf tail case. There are plenty of people that seem to get it working just fine.

[Bullfrog98]

Try using bank switching on the vbar to lower the tail gain when you go to the higher head speed.

[G Steyn]

I've done a lot of vibration testing today.

With the tail servo push rod disconnected I still get the vibration.

It seems to me that the two blades goes out of tracking creating the vibration.

[el guapo]

Originally Posted by G Steyn

I've done a lot of vibration testing today.

With the tail servo push rod disconnected I still get the vibration.

It seems to me that the two blades goes out of tracking creating the vibration.

bad tail blades will do that. try the plastic ones that come in the kit. I've seen that more then a few times on my logo's.

[G Steyn]

Thanks, will get a set today, and try them.

[pwood]

Hi

One other thing worth looking at.... The pressure on the tail box bearings.

Guys tend to sim it until there is zero end float. There should be a little end float.

Regards
Paul

[el guapo]

don't buy the mikado blades. if you have them try them. they come in the kits. if you have a new kit, you should have them... maybe buy some KBDD extremes.

and make sure you didn't flip the grips. tailing edge control can cause tracking issues.

[G Steyn]

Replaced tail blades with Original Mikado blades, Heli is as smooth as can be.

[phranticness]

Originally Posted by el guapo

... maybe buy some KBDD extremes.

I had terrible luck with those. They were really heavy and no matter how perfect I thought I had the balance, they would cause vibrations on my ol' T700.

I want to point out that I've only tried one set, maybe there was something unusual about the set I had. Still, I would think the extra weight could exacerbate any tail issues.