Sticky Tail Pitch Slider

[rza996]

I have an issue with the tail pitch slider. When the pitch slider is on the tail shaft, it slides perfectly, silky and smooth. When I attach the pitch slider to the blade grips, it becomes sticky, notchy and has a lot of friction. I ordered a new tail gear, new pitch slider and new tail hub/blade grips. And the problem is still there. This is making me frustrated. If I can't resolve this, I'm gonna put this 700xxtreme airframe up for sale.

Any thoughts?

[sl4ppy]

I dont think blade grips could apply any friction to the tail pitch slider other than through the bearings since that's all the moves when the pitch slider moves...

Have you checked those?

[rza996]

I checked the bearings, brand new. Blade grips swings perfectly on the tail hub. Each components seems to be perfectly by themselves. But when I attach the pitch slider to the blade grips, it's not so smooth.

Someone suggested I get a ball link sizing tool and make the ball link slightly bigger.

[EEngineer]

Originally Posted by rza996

I have an issue with the tail pitch slider. When the pitch slider is on the tail shaft, it slides perfectly, silky and smooth. When I attach the pitch slider to the blade grips, it becomes sticky, notchy and has a lot of friction. I ordered a new tail gear, new pitch slider and new tail hub/blade grips. And the problem is still there. This is making me frustrated. If I can't resolve this, I'm gonna put this 700xxtreme airframe up for sale.

Any thoughts?

Did you get your 700XX new or used?

Assuming new, a few things to check are:

When you assembled the tail rotor, according to step 6 of the manual, do you have any axial play in the tail rotor grips?

With regards to the pitch slider....sounds like it slides nice...but, check the links where they snap on the blade grips balls....they're kinda like a "one way link".

Prior to installing the "tiller arm", your slider...with grips connected...should be smooth as silk.

Could there be a problem with the slider links/grip assy?

FWIW

[rcmarty]

My 800 was like this , I ended up with a small washer under the ball to the grip part.

Smooth as glass ever since.

My 800 was batch 2 to NA , and my 700 was one of the first to get here.

I now have a later version 800 that doesn't have the issue that both my early 700/800 do.

Quick test to see if this is the same issue as mine is to turn the bolt to the grip back 1 turn and see if it frees up the stickiness


Martin

[EEngineer]

"I ended up with a small washer under the ball to the grip part."

Could you describe what you did more clearly?...

[rcmarty]

The top grip has a small washer under the ball end.
Hard to see as it's a thin washer.

Just enough to cause the slider to move freely.

Do the quick test by loosening the bolt for the ball end up 1 turn. If it slides freely then you need a thin washer.


Martin

[ReadyToCrash]

how is the articulation (in red)? is it moving freely?
how tight are the balls inside the ball holes (orange)? the balls must rotate freely inside the holes. sometimes you need to smooth a tine edge on the balls. this edge is the result of the manufacturing process and sometimes it is just too big.

[taosgraveyard]

And use a little dry fluid Heli there... Works great

[rza996]

Called up mikadoUSA tech support for help. Customer support there was awesome, first class. I sent the whole tail section to them so they can take a look at it. The solution was that they shimmed the ball link on the both tail grips to align the links better. Seemed to have fix the problem. Don't know if they is a common issue with other people or just my heli.

Anyways, I was very impress with the tech support/customer support over there at mikadoUSA

[EEngineer]

Originally Posted by rza996

Called up mikadoUSA tech support for help. Customer support there was awesome, first class. I sent the whole tail section to them so they can take a look at it. The solution was that they shimmed the ball link on the both tail grips to align the links better. Seemed to have fix the problem. Don't know if they is a common issue with other people or just my heli.

Anyways, I was very impress with the tech support/customer support over there at mikadoUSA

So, rcmarty's recommendation was "seconded" by MikadoUSA.

Gotta write that one down....

Nice, marty....

[rcmarty]

Well isn't that interesting

I guess my OCD builds do discover the odd thing sometimes.

I'd assume there are minor tolerances to factor in between the plastic grips , thrust washers , dampners , bearings / etc , all totaled up could cause a minor variance with even a german built heli.

My next though would be .. I wonder if after these items seat/wear/breakin over time would that change the tolerance again ?

Myself , I only could put one thin (quite thin) washer on one side. Struggled with the just one for a few hours and finally said I would try it. Worked perfect and have since forgot that there's only one.
I think I'm going to recheck the fit to see if the washer is too much now. Of course after 200 flights I think minor wear use may allow a larger 'tolerance' spec to the overall slider system.

Martin

[EEngineer]

I'm thinking there would be less wear, since the balls are at the right distance so their movement is smoother.

How thick were your washers/shims?

[rcmarty]

Originally Posted by EEngineer

I'm thinking there would be less wear, since the balls are at the right distance so their movement is smoother.

How thick were your washers/shims?

My thought was if there is an extra washer in there after it's all broke in would that now become too much ?
In reality I think 200 flights later the wear on the tail shaft and brass slider would provide extra clearance.

The washer was very thin , I have a random collection of washers from the years of helis. My best guess is something off a trex 450 , you know those thin ones under the washout / mixer arms so the bearing od doesn't rub on the mounting surface it's screwed to.

I was going to give it a check tonight but got sidetracked.

Martin

[EEngineer]

Hey...it's Mikado "certified" now.....

[stevo6mm]

Had exact same issue with 800x this week.

The tail pitch slider that came in the box wasn't square. That is where the brass bushing with the bearing over it wasn't screwed squarly into the plastic sleeve that holds the connecting arms. The result of course was a terrible tail when connected to blade grip balls. Just looking at it you could see how off centre the conecting rods were from the centre of the balls.

So bought a new one and it wasn't perfect but better. Resolved the stickyness with a single shim washer under 1 ball (0.3 mm Hirobo washer) and took about the same amount of material off the oposite blade grip control arm where the ball screws into it.

Also polished the tail rod of course and also polished the inside of the brass slider. if you have a look inside them with some magnification you can find a pretty knarly surface. Polish only.... do not change the dimensions. 1200 then 2000 grit wet and dry.

Also debured both ends of the brass slider.

Tail now pretty sweet though the single washer and grip control rod sanding plays on my mind a little as being a bit of a hack.

I still think I have to much friction in the the conecting rod joints where they are pinned. Looks like a press/friction fit. Not sure though. either way.. any advice on loosening those up a bit would be apreciated.