Blade Fluttering.

[ricky.davis.129794]

Here recently I noticed on a test stand I built for my 450 pro dfc the tips of the main rotor blades will sometimes flutter. All parts are new and tryed two different sets of blades that are balanced. I've checked all bearings, dampaners and screws everything is tight. I'm running scorpion 3500 with ds 215mg for cyclic and Hobby wing platinum 50 amp esc. No over heating issues need some help or opinions please

[truckermusic]

Please keep in mind that just because everything is new does NOT mean it is straight and / or correct..It may be off a little bit.

this is what I would look at:

1. Is the feathering shaft New? Is it STRAIGHT?
Are you sure that you put the Thrust washers in correctly?
2. are the thrust washers installed the same on both sides?
Did you put locktight on the thrust washer screw? if so did any leak out into the bearing?
Are the screws them selves tight? are they tightened the same amount?
3. are the dampers good?
4.do you have washers between one blade grip and not the other?
5. are the blade grips of equal weight? (with the thrust washers installed? if not then apply a little bit of JB weld to the light one to match the heavy one.
6. Is the main shaft REALLY straight?
7. is there any slop in the head when it is completely installed on the heli?
8. with the head completely installed pull up on the head. Is there ANY slop? If so add washers between the top bearing and the putrusion on the main shaft so that there is no slop. (on my 450 I always put two washers on an it is tight.....NOT overtight to hurt the bearings...just tight enough to take up the slop.
9. with the head complete and the main shaft installed into the head but not installed in the heli.....Is the complete assy balanced????
10 is there any slop between the grips and the blades???? if so add two identical washers.....weigh them to make sure
11. are you sure that none of your screws are over tight and causing any binding? especially in the grips, and the links.
12. are you sure that ALL your bearings are good?
13. have all the bearings been lubbed or greased? INCLUDING the thrust washer......
14 is there any binding in the ball like to the swash? these need to be free to turn but not sloppy free...
15. Have you ever lubbed or greased the swash?

These are just some of the points I would look at to get you started.

Clifford

[PilotPin]

Are you running it tied down to your test stand? That could be the problem .

[HEXAHYDRATE]

Securing a heli firmly to a stand can literally destroy a heli to pieces. Ask Dan Reid from RCHN lol. Bad idea. And as mentioned obove it is likely your problem.

Your gyros will try to compensate, and if everything hits just the right frequency look the hell out!

Do test spool ups with no blades if you have to test stuff.

There should be no such thing as a test stand.

[mickeyjohnston]

Originally Posted by HEXAHYDRATE

Securing a heli firmly to a stand can literally destroy a heli to pieces. Ask Dan Reid from RCHN lol. Bad idea. And as mentioned obove it is likely your problem.

Your gyros will try to compensate, and if everything hits just the right frequency look the hell out!

Do test spool ups with no blades if you have to test stuff.

There should be no such thing as a test stand.

+ 1.

[ricky.davis.129794]

Originally Posted by HEXAHYDRATE

Securing a heli firmly to a stand can literally destroy a heli to pieces. Ask Dan Reid from RCHN lol. Bad idea. And as mentioned obove it is likely your problem.

Your gyros will try to compensate, and if everything hits just the right frequency look the hell out!

Do test spool ups with no blades if you have to test stuff.

There should be no such thing as a test stand.

No it is not secured, flying I can hear it, landed it and bench tested and it confirms blade flutter

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