600/700 tail mod.

[GravityKills]

...Maybe I've been lucky thus far

I haven't. About €400.

[Andy from Sandy]

To be honest I think 1/2 the problem is that the thread in the grip hub is not deap enough allowing too much play with the bolt fully tightened - probably why the factory chimps are tightening them up too much in the first place.

Once you clean all the old loctite out of the hub you will find that it will take a 10mm bolt. So the mod to fit a 4mm wide bearing and a 12mm bolt, you could if you wanted use a 14mm bolt.

I am sure you could find the engineering principles to how long a bolt needs to be.

[jamiem]

I should have updated this to say i've fitted mine and it eliminated all side to side play in the grips, and sure enough, my original bolts were stupidly tight. I'm happy for the sake of £3 odd!

[kairey]

Just realised I have the Quick UK grips on mine I forgot that when I posted above, I guess they don't need this mod?

Will take a look at my 600 though!

[Rctintin]

Rctintin what tail rotor control arm is that you have on there doesn't look like the Align upgrade...?

It's this one:

Fast Lad Performance

[GravityKills]

I added the 3rd bearings to my 700, but haven't done a test flight yet.
It seems like a good idea. Lateral play is basically gone.
Notes:

• I used a thin washer between third bearing and thrust bearing. The screw head sits cleanly on the inner race of the new bearing, so I omitted the original washer.
• After filing off the edges, the Radix blades can be folded back over the screw head (barely).
• I added some tape on the 3rd bearing to reduce play. It helps a lot, but I'm not sure how long it will last.
• The thrust bearings (upgrade tail rotor) needed some grease, badly. I wonder if they were lubricated at all at the factory.

[jamiem]

I used a high tensile button head screw on mine, so clearance to the tail blades is fine

[gazza]

I fitted this mod on my 600LE this evening
Although a massive improvement I noticed on assembly that the M2 Caphead bolts supplied with the replacement CNC links don't like to be very tight at the brass bushing side otherwise quite severe binding occurs

As it stands they are 'Only Just' Nipped up and this allows a smooth & free action.
Obviously I've locktited them in but I'm still a little nervous about them!

Anyone else found this?

[Rctintin]

Yep, same as. I just used locktight on the thread, and then just nipped up the bolt till binding started and then backed it off a hair.

[GravityKills]

Hint:
CNC links are IMO not that great, because they are heavier than plastic.
It may even overload the tail servo, if it was already "on the edge".

It's hard to believe, until you've tried to spin up the heli on the bench without blades, and operate the rudder pushrod by hand (this experiment is easily done on a 450). The return force caused by such links trying to fly away is amazing: Of course they can't fly away, but they will always spin on the biggest possible circle, unless forced otherwise. That's the problem solved by "chinese weights".

PS: Test flights on my two 700s are done, and it works just as expected.