E5SS Head Wobble

[Forced_Induction]

So far im loving my E5 super stretch.  But im having a head wobble issue. 

Im using switch 713mm blades that are perfectly balanced both c of and weight.  headspeeds are 1600, 1800 & 2000 rpm.  it wobbles in all flight modes.  Ive greased the dampeners and tried 2 other shim configurations.  i believe the shim thicknesses are 1mm, 0.8mm & 0.5mm.  with the 1mm shims theres no play and the grips rotate freely.  with the 0.8mm shims, theres a small amount of play that the feathering shaft will slide back and forth.  with 0.5mm and 0.8mm for a total shim thickness of 1.3mm, the grips start to get notchy.  i havent flown with the 0.8mm shims as id think the play would make things worse. 

blades are tightened evenly and tight enough that i can tip the heli on the side and they stayin place, but a small bump will make them fall. 

It will spool up nicely but once it reaches speed it wobbles.  it also wobbles worse on spool down if i give it hard negative to slow the rotor head.

anyone have any ideas?

[Rodney Kirstine]

Are the dampers new or do they have some flights on them?

[Forced_Induction]

Less than 10 flights on the heli. I've tried using 0.5 and 0.8mm shims and it was much worse. Last flight I tried the 0.8mmshims and loosening the blade grip bolts and its good in flight, but still has the wobble on spool down.

[Rodney Kirstine]

Give it some more flights to break in the dampers and it should smooth out.

[Grimmy]

Make sure the dampeners are oiled as well.......not dry.  I believe it's stated in the manual.  I use Triflo (sp?) on mine.

[Forced_Induction]

I did Grease them before installing.

[Jbiter]

I know you checked blade weights and CG but have you tried another set of blades? I have Rail 696 on mine and it has been smooth in all flight modes.

Jeff Biter

[Forced_Induction]

New blades will be the next thing I try. I have 16 flights on it now mostly at 1800 rpm and have found that using the 0.8mm shims and keeping the blades fairly loose has stopped the wobble in flight. It still shakes on spool down but its fine in flight now.

[FrankFuss]

It still shakes on spool down but its fine in flight now.

Mine shakes on spool down also, but seems to be good when spooled up.  I run my blades tight at low headspeeds (1400, 1550, 1700) with 14° collective and 14° cyclic pitch.

[fran11784]

Humm that's interesting. I'm dealing with a spool down shake on a scale project I used a new E5 head on. All my Synergy's I never had any wobble or shake of any kind before. I figured it was because of the 1300 head speed. I'm trying to find some softer dampers...
Tony

[gwright]

Have you checked the chordwise CG to see if the blades match?  Unless you have a Koll Rotor Pro it's difficult to actually measure, but you just need to compare the two blades. Put a bolt or nail in something, cut off the head,  and hang both blades from it. Look at the bottom which will be the tips. See if one leads/lags more than the other.  I sometimes see a bit on spoolup/spooldown on hard surface, but not always.  Never see it on spoolup/down on grass.  currently running 1200/1450 for headspeeds, 95% of the time at 1200,.. and 16/16 pitch, and blades on the snug side. Rail 696/116's.

[fran11784]

Don't mean to hijack a thread but I didn't mention this was a scale project. Running 800mm semi symmetrical Spin blades. I found a mistake a made with the shims. I had a thick and a thin against the dampers and a thick and a thin in each grip. Hoping that makes a difference. I now have the thick ones against the dampers and thin ones inside the grips as the manual states. I will check the blades as well. Thanks...

[Cliff600]

I had the same issue with a E5SS that I just bought.  I found out the bolts that go through the blade grips into the spindle was loose.  I tightened them up and it fixed my issue.