Sticky tail slider

[RunarSL]

This spring I ordered the new tail precision slider for my 700C. The oldschool one worked fine, it was just a little bit sloppy.

The problem with the new one is that it makes the tail sticky an notchy. The slider runs fine on the shaft on its own, but when i connect the fork it seizes up. The last hours has been used sanding, buffing and polishing both the shaft and inside of the brass slider, and it runs flawlessly without the fork. I have rebuilt the tail and the control rod is free.

Anyone seen this on their Goblin? Any tips?

[B.Ewing]

Same issue on my kse slider. Everything is smooth until I connect to the blade grips. I backed the screws off a hair and it's smooth, but sticky again by the next time I check it. It actually flies fine tho surprisingly. That being said I've only got 3 flights on it and haunt started pushing yet

[alexmit]

Originally Posted by B.Ewing

Same issue on my kse slider. Everything is smooth until I connect to the blade grips. I backed the screws off a hair and it's smooth, but sticky again by the next time I check it. It actually flies fine tho surprisingly. That being said I've only got 3 flights on it and haunt started pushing yet

This is also my experience with the SAB precision tail slider. If the bolt that holds it to the bracket attached to the tail box is too tight, it will bind. I have ordered additional shims to put between the bearing and the bracket to see if that aligns it better for smoother operation. The only other thing I can imagine is that the spacer/insert between the 2 flange bearings could be a tiny bit short causing the bearings to bind when the screw is tighter. I have not tested any of this yet, but I have 2 bags of the tiny shims to see if it helps. I hope to try out the extra shims sometime next week to see how it works or what the solution is. I have seen this on my 700C and 630C that both have the Urukay-style precision slider. For now I run the bolt looser, but held in place with thread locker.

[earhythmic]

From what I gather this is a common issue on most Goblins, usually due to the tail assembly being a tiny bit out of square when assembled. I struggled with getting the slider smooth and it took a little patience. I put the tail together with the pitch slider and shaft assembled, but kept the side screws of the tail case loose. I would snug one screw at a time and continue to check the smoothness of the slider. If it would start to bind then loosen the previous screw and do some light twisting/aligning with the tail box until the slider was smooth and then proceed. When I was done I had a completely smooth slider without needing to grind or sand. Took about 10 minutes.

There was some discussion in the Urukay thread regarding it. Post #109
https://www.helifreak.com/showthread...=666580&page=6

[B.Ewing]

im going to have to look at my tail a bit closer. its pretty smooth now but slightly sticky towards the far ends. In flight, it hold perfectly except in nose down funnels...it feels like its getting stuck because the tail lags behind the input and then pops into place after i unload it.

[alexmit]

Originally Posted by earhythmic

From what I gather this is a common issue on most Goblins, usually due to the tail assembly being a tiny bit out of square when assembled.

This particular issue should only apply to the Precision Tail (Urukay) and similar aftermarket sliders. I cannot replicate this with the stock slider, so it really isn't "most Goblins". :-)

[alexmit]

I went back through the tail today and determined the following. The tolerances on the precision tail are just that… precision and tight. I took the belt off the front pulley then moved the tail box to the same vicinity it was when the tail belt would be tight, but with the belt off and tightened all 4 bolts that attach the tail box to the tail boom. from there I loosened all 8 fasteners on the dial box sides and started to tighten them equally in a circular pattern. If the slider became sticky, I just torqued the tail box by hand until it moved freely and tightened the fasteners more and repeating the process until the fasteners were tight and the tail slid freely. No sanding or shims were required. It just takes a little more effort to get perfect alignment because of the tolerances on the tail slider forks and pins. All is good now.

[bbockstanz]

What I found when assembling the KSE 700 was if any bit of thread loc got in the sleeve and the link, it would bind up. If you assemble it without the loctite, it slides smooth. I took it all apart and cleaned all the pieces up and made sure I put the loctite on carefully and it moves nice and smooth. Took me several times to figure out what was going on.

[B.Ewing]

^ exactly what im finding. im just not being careful enough with the loctite

[fluxcapacitor121]

Glad I found this thread. Was tearing my hair out trying to get the SAB dual pin comp slider to play nice...tried extra shims, no better. Was just about ready to go back to the stock slider when I found this thread. My tail was not square. Loosened all the bolts on the tail box and re-tightened. Butter now. Thanks guys.

[mba83]

This thread solved my mystery, thanks guys!

I had to assemble the tail case while bolted onto the boom - otherwise the 4 bolts connecting them would mess with the geometry.

I unscrewed all screws, then connected tail case halfs to the boom, squared it, and tightened all screws while verifying that the pitch slider is smooth.

If it binds on the left/inner side, rotate the tail case clockwise (looking at it from the back). If it binds on the right/outer side, rotate it counter-clockwise.

I wonder if the metal side-plate fixes this issue? Mine is carbon fiber, but I have the metal one as a spare that I didn't try yet.

[mba83]

FYI, the metal side-plate does nothing to fix this issue.

[Luvmyhelis]

A while back a dedicated thread was posted by AViking. There is no consistency in how wide the tail booms are. So due to this, some CF tail frames V more at the bottom when tightened. That angle affects the slider assembly. the factory single sided sloppy one doesn't care, but the new tight dual control arms do. Some guys shimmed their CF tail halves to solve it, effectively squaring the tail box. I ran across this years ago when fielding one of the very first KDE dual sliders.

[CaptHal8HS]

Well, I'm a little late to the thread; glad I found it.
I too have been suffering from the "sticky" tail slider. This thread came as a welcomed relief as I am experiencing an unsettled tail in flight - no doubt to the binding that I'm seeing. No tuning would settle the tail down; it just wasn't locked in and solid.
However, despite all my tweaking, twisting and twerking of the tail cage, I just can't get the tail slider to not bind. So I went back to the original tail slider.
I don't understand this as I build 2 Black Thunder 700's with this tail mechanism and had zero problems. Yet, this tail slider binds on the bearing side... badly. I did order the Lynx upgrade, but I fear I will have the same problem with that unit if the logic as to why we see the binding holds true.
Any input is greatly appreciated.

[A VIKING]

Having a smooth tail slider on a Goblin is a function of two things...parallel and square.

If the side plates of the tail box are not exactly parallel to each other and exactly in the same position fore and aft after the side bolts are tightened down, the tail shaft will be pulled out of square with the side plates and the tail slider will bind up on the shaft as it slides.
That binding can happen anywhere on the shaft being determined by the side plate position and not being parallel.

Logic will tell you that if the tail slider works smoothly in your hand, it should also work smoothly on the model. If it does not, the side plates are not parallel and the tail shaft is not square to the side plates.

We have a "precision" tail slider assembly mounted on a not so precise and flexible tail boom surface which screws the whole thing up.

Getting out the sand paper only puts a thousand flights of wear on your precision tail assembly so don't go there. Make sure your assembly is parallel and square and it will be perfect.

Past all the work we go through to make it right after installation, SAB needs to abandon this method of tail box assembly and make a one piece, machined tail box which won't have these undesirable tendencies of binding. IMHO

Sometimes you can get lucky and it works first time without binding but in my case that has never happened which is why I spent so much time trying to figure it out.

My current model has a one piece tail box and you can remove it and install it a thousand times and the tail slider works smoothly every time.

I do love SAB though...just not their tail box.

[A VIKING]

...and just an observation of mine.
Looking at this thread I see over 1000 hits. That tells me there is a very distinct problem with the tail box and slider design.
There should never be over 1000 hits on any design issue, they should be fixed by the manufacturer whoever they may be.
Those 1000 hits are just on this one thread alone, there are countless other posts concerning the same thing.

SAB I love you but you know what the problem is...please fix this so we don't devote so much time on it, we would rather be flying your beautiful machines.

I'll step down off the soap box now...Thank You

[CaptHal8HS]

I went back to the original slider and the binding is much better - not perfect, but better. My model even flies better - no more weird tail movements.
SAB, I love you but you have to come up with a new design here. Or Lynx has to come out with an upgrade that fixes this. #disappointedinSABbutIstillloveyou

[CaptHal8HS]

Just a quick follow up. I was at the field today and inspected a buddy's 700 Black Thunder and noticed something pretty interesting.
The rudder lever has about a 1mm of vertical play. I asked him about it and he told me that that was normal (where he was getting that information is still a mystery). But I do know that the replacement tail slider upgrade that I had ordered and later returned, had the same vertical play! I returned it because I thought the part was defective somehow. But based on how his tail flew, I think this vertical play is there in order to alleviate any binding that may occur with the pins as the rudder lever travels along the horizontal plane. Just a guess, but his tail shaft shows no sign of binding and the tail is very still in the air. Furthermore, the two other 700BT's that I built for another buddy have well behaved tails.
I think SAB should somehow address this with a new/different design in the future for their tailbox assembly.

[etherbatxx]

Originally Posted by A VIKING

Those 1000 hits are just on this one thread alone, there are countless other posts concerning the same thing.

you shouldn't assume number of hits equal design problem.

i ended up here by accident.
i'm sure others have too.

[A VIKING]

Originally Posted by etherbatxx

you shouldn't assume number of hits equal design problem.

i ended up here by accident.
i'm sure others have too.

I appreciate your viewpoint but in my own defense, please let me explain my statement.

First, I try to never assume anything.

I believe 99.9% of all who take part in or look through these forums and threads have one of three needs to satisfy.
"An Interest" in the forum title/subject or thread title/subject.
"A need" from the information found in the content of the forum/subject or thread title/subject.
"A want" of what ever the forum title/subject or thread title/subject has to offer.

I believe the "View" numbers reflect the participant satisfying one of those needs listed above,
I have never accidentally ended up anywhere on the forums.
There are many forums here I would never visit because they don't match my list of needs.

I do use the "Views" number as a quick indicator of issues that I may encounter if I purchase whatever product the forum is about.

If I want to buy a particular heli, I will first look in the vendors web site to get my first impression and if I like what I see I will come directly to Helifreak and look for the forum of that model.

I will open that forum and look directly at the "Views" number to see what has the highest number, once identified, only then will I look at the subject title of the thread to see what its about and then open it to see its content.

It's nice to know what you may be up against before purchase.
Has this research ever stopped me from making a purchase, no, but it was good to find out ahead of time what to be be aware of.

What did I see in the forum before purchasing my first Goblin...slider issues and that was years ago and we can still see threads today about that same issue once again.

So I will stand with my statement, it's not an assumption.

etherbatxx...I absolutely respect you and your thought on this and it is a valid one, I am just explaining the thought process I go through to justify my statement.