Tail rotor, do I need a lubricant?

[Andrewlik]

Hi all, recently my goblin 630 has crashed, due to tail pitch sliders was stuck on tail rotor shaft in flight, I always check, clean and apply some tri-flow before go to fly, in some other forums, I was told that I should not lubricate it, that's why it jammed. But I doubt that it happend for this reason. So I want to hear your opinions and tips... Thanks

[Skidpad]

Sorry to hear about your crash. Tr-flow is a very thin lubricant that doesn't gum up; I doubt lubing your tail with tri-flow caused the tail to lock up...I've been lubing my various helis for a couple of years without issue, and if you've cleaned and lubed yours regularly you are familiar with its properties.

Was there another failure that caused the tail pitch mechanism to stick? Bearings?

[kavic5150]

Edit: Skidpad beat me to it. +1 for Tri-flow.

All moving parts need to move freely. The tail slider you mention especially needs to be lubricated. I would recommend lubricating any metal on metal moving parts, even the little ball at the center of a swashplate. All fast moving bearings should be lubed regularly with a light lubricant.

You can even lubricate the tail belt if your heli has belt drive, though some dont. I recommend it as it reduces chances of static electricity interference and decreases rolling resistance.

I was advised to avoid any belt lubricants with graphite, petroleum products, or anything that says "dry formula" or has additional additives as these can gunk up bearings and make a mess.

[RedOctobyr]

I put an occasional drop of TriFlow on my pitch slider.

Sent using Tapatalk.

[Atomic Skull]

Originally Posted by kavic5150

even the little ball at the center of a swashplate. All fast moving bearings should be lubed regularly with a light lubricant.

Use plastic safe grease for the swashplate ball not machine oil. To apply grease to the ball take the swashplate off and turn the ball sideways so that the hole for the mainshaft faces into the swash and exposes the inside and apply some grease around the plastic ring that holds the ball. I use super lube for this, it's safe for plastics and synthetic rubbers and has a better consistency than sillicone grease.

[mqowen]

I lube everything every few flights. A slider might become sticky if lube gets dirty and never cleaned. I think the benefits of lube outweigh the risk. And the risk is controllable as long as the parts get cleaned periodically.

[Ah Clem]

I use TriFlow liquid and make sure things stay clean.

If I am at a meet where we are flying from pavement, I make sure that I keep the slider clean. After cleaning it, I re-lube it.

[TucsonFlyer]

Personally I do not lubricate my pitch slider. I fly in a high dust environment and it just gets grungy, even using triflow. I find that the brass slider bushing is fine by itself most times and that if it's a bit sticky it can generally be fixed by putting the tail shaft in a drill and very lightly polishing it.

Anyone know if the bronze inserts on tail sliders are of the self lubricating variety?

[Ah Clem]

"Anyone know if the bronze inserts on tail sliders are of the self lubricating variety?"

I don't know. If they are "oilite bronze" they still need periodic lubrication.

[Atomic Skull]

They're just plain brass tubing. Personally I prefer ball links on the tail over dogbone links. Less slop and easier to service.

[helibeli]

I always put a drop of oil on the shaft and the main shaft after a few flights using a hypodermic neenle full of oil.Clean and precise.

[Andrewlik]

I always cleaned and checked it before each flying day, I have only about 50 flights on this machine! so I could not imagine myself how could this happend.
The slider stucked at this position..

[Ah Clem]

On some machines, the slider linkage can go "over center" and lock in one direction. The older Trex 600's could do this.

Limiting the travel just before they got in a position to lock would prevent it from happening.

[blade450]

I don't lubricate. I just clean my tail shaft every now and then. Lubricating it seems to make it attract dirt faster, and it is very smooth without.

[airpup86C]

Originally Posted by Andrewlik

I always cleaned and checked it before each flying day, I have only about 50 flights on this machine! so I could not imagine myself how could this happend.
The slider stucked at this position..

If it's actually stuck so you can't move it easily, I'd say the most likely cause is a slightly bent tail shaft. Perhaps it got bumped in transit, or the tail was bumped on the ground on your last landing? In my experience, when they bend, it's usually close to the tail housing, so you might have been able to fly it OK until you called for full rudder. It couldn't be bent very much, or you'd have probably noticed some vibration.

At any rate, you'll have to take it apart to see what's up. Let us know what you find.

Al

Edit to add. Of course, if it's bent now, I could simply be crash damage.

[dyuen888]

Ah Clem..
On some machines, the slider linkage can go "over center" and lock in one direction. The older Trex 600's could do this.

Limiting the travel just before they got in a position to lock would prevent it from happening.

+1

[PowerDyne]

Originally Posted by airpup86C

If it's actually stuck so you can't move it easily, I'd say the most likely cause is a slightly bent tail shaft. Perhaps it got bumped in transit, or the tail was bumped on the ground on your last landing? In my experience, when they bend, it's usually close to the tail housing, so you might have been able to fly it OK until you called for full rudder. It couldn't be bent very much, or you'd have probably noticed some vibration.

At any rate, you'll have to take it apart to see what's up. Let us know what you find.

Al

Edit to add. Of course, if it's bent now, I could simply be crash damage.

I actually had something very similar to this happen a few weeks ago after a tail bump. The slider seized on the shaft where the light bend was. I ended up having to cut the shaft to get the slider off.

[irresponsibility]

I use dryfluid Heli on the slider. It is far more slippery than when I used tri flow, and it doesn't gum up.