Lepton vibrations

[Jafa]

This has been giving me a lot of trouble
Every 3rd or 4th flight she would come home shaking
I learned which blade grip to tug on - to centralize the spindle - this fixed the shakes
But I got sick of doing that!

I pulled the head appart, put the grips back onto the spindle
and measured between the spacers that butt up against the grips
it was an odd size, something like 30.1mm
So I put a Hirobo 6 * 0.1 shim onto one side
and reassembled the head

Today this has significantly improved matters.
It's taken out 60% of the vibrations
So Im thinking of packing the head a little more

[Finless]

I had this exact same problem too and it was a funky set of Hirobo FP blades. I got a new set and didnt have the problem anymore. CF blades later also never gave this problem. I assumed though dont know that it was having a lead lag problem.

Bob

[Jafa]

Yeah - I switched from the white FRP to CarbonTech blades - did not solve the problem for me

The way to test is to try and push the main blade grips in and the pull them out
If you can find a little slop then you need to pack the spindle
I put the spacer between the standard spacer and the grip

[rotodingo]

Can you give us the ref number of the shims you are talking about? I want to reduce the slope too.
Thanks

[Jafa]

Hirobo 2526-021 Flat Washer 5/7/0.1

[rotodingo]

Thanks a lot! How many shims in a bag? 10? Do you have some other ref numbers for this kind of shims? It's so hard to find...

Nicolas

[Jafa]

I think there is 5 in a bag actually

I do have other Hirobo shim part numbers
but none fit the Lepton (other than the one above)

[rotodingo]

Yes, but they could help on other helis. This kind of shims is very hard to find. So it will be helpfull to me to have some other ref numbers about this shims. Having several sizes in stock could be the answer, one day, to anothe rproblem.

Nicolas

[Jafa]

2506020 Flat Washer 5/10/1T
2506029 Flat Washer 08/08/0.3
2506019 Flat Washer 03/4.5/0.5T
2506041 Flat Washer (Under grip bolt) 05/12 1.5T
2506035 Spindle Spacer Washer 08/12 0.1T

[jonny_volts]

Hi guys
Vibrations in my lepton tail have caused one of the screws holding in one of my boom supports to shear any suggestions to stop the vibration its a horizontal vibration and I beleive I have eliminated the gyro as a suspect.

[John Heli]

I had horizontal vibrations and tried a lot at the tail, but finally it was the same problem mentioned above: I found a packing configuration for the head which stopped the vibrations in the tail.

[jonny_volts]

There were no shims neede as there is no play in the head I have regreased the spindle and it seems fine whats the idea behind the raptor 50 boom supports, does theat help this problem

[Jafa]

There is no play in my head either (the metal components)
but the spindle was able to move left/right up to the dampers
Some people have this problem and some don't
Some people got poorly balanced white blades, some got good ones

[John Heli]

Do you think instead of packing the head with more stuff flatzening the spindle on each site a bit would be an option?

[Jafa]

Yeah sure - but hard for us average folk to do that accurately (0.5mm steps)

[John Heli]

Hm, you're right. Maybe I can find someone with the right tools. I thought of taking 1/5mm apart of each side.

[John Heli]

I just thouht why not messing up one spinde. I took apart maybe 1/5mm each side. The head is much more packed now. I tested it and .... the vibrations are much less. I can recommend doing it. By the way: You do not need to be 100% precise because the spindle can move in the head.

[Rush]

John, i'm gonna try this. I think you are right that you dont need to be that accurate as the spindle should, in theory, center itself between the two blade grips and the hub

[John Heli]

Finally I found another mistake I made: I used the wrong grease. It affected the dampers, they hardened and caused vibrations in spin-up and -down. Changing the damper rubbers and using rubberfriendly grease made my vibrations go away even with the unshortened spindle.

[lepton ex123]

Please help I'm new and a raw beginner to the hobby.
I've just finished my lepton and as it's my first helicopter I'm worried about the vibrations when I'm hovering,I can't do curcuits or anything else yet but I noticed the landing gear vibrating and as I looked up it's the whole heli.
My equipment is axi 2826/10 motor,jeti spin 55 esc,fast 2.4 radio,futaba 3150s,401 giro with 9650 and flightpower 4s 3300 battery.
I don't think it's the giro as the tail is locked in,and my head speed is about 2200rpm,also the throttle curve is about 55% mid hover.
I'm worried in case anything happens cos it took 10 months to collect everything together.
It's not uncontrollable at all it's just annoying.Thanks for any replies.

[John Heli]

First point: Are the blades well balanced? And are the blades and the paddle in the same track?

If so: Did you grease the spindle?

[jyheli]

Vibration can come from many places.
You can start by stripping the main and tail blade. Spin it up and see if there is any vibration. If yes, start dropping a few more thngs starting from the head/swash/etc... leaving just main shaft and see if you still see any.

Jonathan

[lepton ex123]

Thanks everyone,I was told by bob that the headspeed was too low and to bring up the throttle curve to 85% and it seems to have worked,perfect now and I re-checked the balance of the blades which seemed ok,so anyone else with the same vibes it might be worth them doing the same,cheers.