lateral stick movement

[500E]

We have a H500 with lateral shake on stick, there is NO shake in fore & aft plane.

Both trim motor were shot! both replaced & correctly adjusted.

All head bearings worn & replaces same with droop stops.

Swash plate bearing good 6 months old.

No wear in pitch link or rod ends.

With no blades on the head is staring (after balancing).

We tried another head, swash plate & bearing , (This head & SP was perfect on the one we removed it from) the shake was still there it is only lateral about 1\2inch but there at ground idle & in flight, cant feel it through pedals but there is a slight drumming you can feel in the hull, but does not seem to be in sympathy

Checked pylon bolts & pylon for any visible damage, gear box mounts.

Engine mountings\ alignment, OK short shaft,OK tail rotor drive shaft OK.

The stick shake appears to be in time with the rotor speed RPM

Driving us to drink any ideas.

[Guest pokey]

didn't you have this similar problem a few years back? it boggled my mind then (& i suggested all the same problems that you said were not) Changing the swashplate AND the head?! !! & still having the same problem?,,, well that eliminates that !......and no blades,, that is gone too. & all the mounts of transmission and the controls?....leaves the main rotor driveshaft?

 

You never did tell us what the last problem was. Is this the same ship?

 

i love problems like this! wish i was there to help.(i'v had heaps of helicopter problems that i have never solved)----well but what i mean by never solving, i mean never gotten to the real source of the vibration, masked it, trim tabbed it, painted it, twisted it. As in every good helicopter mechanic is taught to to (yes capatin)

 

Who was it that said they added FOUR hundred pounds of weight to the head of a ? (407)??? i mean,, that was a SERIOUS problem. (one like the one that got away)

 

but? this side to side?,,, i'v thought it over & over in my mind. NO solution , yet.

 

good luck

 

500's fly really smooth once ya get them worked out, same as 300's, ty Howard

Edited June 17, 2017 by pokey

[Guest pokey]

read this again, thought i had solution, but??? nope,, yer drivin'?,. i'm drinkin.

[Hobie]

Drinkin' At 8am???

[Guest pokey]

At 8am???

 

why wait? can you tell the vibration problem any earlier?

[500E]

Hi Pokey

Not the same ship

Still driving us nuts, the last one was a broken spring in trim motor just one turn, we find a lot of trim units way out of adjustment, a lot of delay in feeling it adjust, that one no delay, but when you cycled it felt slightly strange! pulled it & bingo.

This one has 2 new units Borrowed a shaft to try will let you know

[500E]

Well bit the bullet & removed MGB found metal around output gear & spalling on gear not good (this has not got to filter or Mag plugs) there also appears to be wear on drive shaft gear but need x10 to see.

Problem now is what has caused it, gear box, bent mast causing shaft to run out of line or ??.

Whatever big bucks & until you replace you don't know if it is the cure to original problem

[500E]

Box gone for re build + new shaft not good, any one had mast support bent or damaged other than accident ?? I have a reason to ask