Bretuk

My Trex450seV2 has a drive belt problem. I had to cut off the belt which became tangled with itself, (inner of belt teeth catching) inside the boom
when inches from the ground to a grinding halt, lucky I was not any higher or heli would be a right-off.
Before it happened I noticed it made this clicking/rubbing noise in boom when the heli did a hover for more than 1-2 minute, before the flight I rotated the head,no rubbing or clicking noise, everything as normal and after a 1-2 minute short hover I left the heli for 30 minutes and to my amazement the clicking/rubbing noise had gone, again when I rotated the rotor head. I bought another replacement Align belt, installed and made sure all the tail housing unit was all square and level, belt tension ok, boom is straight all screws tight and belt 90 degrees twist. Tried it again as above and still this belt is catching inside the boom once the heli spools up after 1-2 minutes and the boom is warm, again leave the heli for about 30 minutes then hand rotate the rotor head and nothing rubbing or clicking all normal and quiet.
Is this belt EXPANDING and becoming slack ( I did tighten belt when after the hover and no good) because it will be grounded till the problem is solved.

Georges Payne

Looks like you covered everything.

Do you lubricate the belt? If so, what lubricant do you use? I'm just thinking out loud here, but maybe the belt is stretching a little when hot, and it would not stretch as much if it were well lubricated because then it wouldn't heat up as much? Or maybe for some reason it gets caught in the cogs and that causes it to follow the pulley instead of going directly back out ? Like if the pulley was too small for the belt?

Good luck and keep us informed if you find the cause.
George

Edit : Typo

BryFlyGuy67

Georges,

What do you recommend for lubricating the tail belt? I have been told that "Super Lube" brand works well for this, the kind in the spray can. I have heard others say to use only dry lube. I can see pros and cons both ways.

Bretuk

All cogs are ok and move freely, i dont use any lube like silicone, the belt has no signe of wear looking brand new, its catching on the inside edge of itself(teeth) on the 90deg cross over in the boom

matador_24

I didn't know I had to lubricate the tail beltof the t-rex... do I have to??? with what???? WD-40???? I just put some 1-3 oil in the tail shaft.

Georges Payne

You will get as many answers as there are users on this forum... Me, I use a silicon lubricant that I bought at an electronics supply store. It is garanteed not to harm plastic, and my belt stays nice and clean and it seems to be working. People tend to think for some reason that silicon based lubricants are sticky, but it's not the case. It would kind of defeat the purpose anyway. Some people use WD-40 on the belt, but the stuff is solvent based, contains all kinds of soap and detergent and rust inhibitors (which I don't need) and leaves only a very small amount of lubricant once the carrier fluid and all the other $h1t have evaporated or dried. I never trusted that cheap stuff, never will. I use white lithium grease for the gears, doesn't seem to melt the plastic either.

Your mileage may vary.

Regards
Georges

BryFlyGuy67

Thanks! I will try lubricating the belt with the Super Lube. I have three Gates belts on order, so if it starts looking frayed or stretched, I'll just replace it.

For the main gear, I am going to try a dry lube.

rlsloan

A timing belt should never be lubricated. It is simply a scaled down version of what you use on your car. Most most manufacturers simply recommend changing it at 100,000 miles.

BryFlyGuy67

Um, my car doesn't have a timing belt...

I wish I could get a straight answer on this question. You say not to lubricate. Others swear by it. I'm new and am just trying to figure out how to best maintain my Heli.

ksechler

Generally speaking you don't lubricate belts because it can make them slip and will also degrade the rubber. That said, the Trex belt has to wrap around a very small gear and also rubs against itself where it makes the 90 degree twist. For these reasons and through trail and error I have elected to lubricate mine. I lubricate it lightly with a silicon lubricant when it's new and never again. This keeps my drivetrain very free and my rotor takes considerably longer to spool down when power is removed than without lubrication. It really is up to you, though. Some do some don't.

BryFlyGuy67

Thanks for that info. Let us suppose that I am going to lubricate my belt - once - when it is new. Is Super Lube an acceptable lube for this application? How do you apply your lube? I have read that one way is to slowly rotate the tail rotor and spray a small amount of lube on the pinion or pulley while moving the belt.

Bretuk

Yes on http://runryder.com I was advise to remove the tail pulley on tail housing as others have removed theres and now have no problems.

matador_24

Hi, I had never paid attention to my tail belt until I saw this post....... I had to replace it because I overspeeded the heli without blades (I didn't know that could happen ). Anyway, not it's brand new, it's well tighted but now I see there is some "black dust" around the tail rotor, I guess it comes from the belt... why????? is it normal or I have to lubricate it?????? before reading this post, I never lubricated my tail belt and I didn't have problems for maybe 30 flights until I made the mistake mentioned before. Do I have to lubricate????? what does it prevent????

Dave_E

I concure with that George! As an old auto technician, I can tell you "they used to lube in the old days", now they don't. Aviation maintenance taught me that lubricants actually harm rubber. So I've got 60 flights on the heli and my belt looks like it did out of the box. I'll continue this experiment untill I see wear... and then spend a couple bucks for a new one. Dave

alfredbmor

I think that many of us want to do many things to keep our machines flying at its best, but your opinion it's very accurate, I don't see the reason on spending time or money when the replacement will be in a long time and will cost only two bucks, is also mentionable that actually all belts in our cars work with out lubricants and they do pretty fine for a long time. Looking at the manual there is no advise on lubricate the belt. Now about the friction, we should hear opinions of those that have the same heli and have had problems with it, if not, surely the cause would be a poor assembly and could be easily fixed disassembling the whole tail system and checking part by part, maybe one pulley is getting old and need replacement or the tension is not the adequate.

BryFlyGuy67

I hear you, I hear you. Again, it's just hard for a n00b to sort everything out, as the opinions on this seem to be evenly divided between lubing and not lubing. If it were not for the crossover inside the tail, I would be les concerned.

Lubing the tail belt aside, what about some Tri-Flow / Super Lube on the tail rotor pulley and pinion on the tail end?

IM-A-PRO

A silicone lubricant should work great on the belt. Go to any popular sporting goods store and look for a small bottle of "treadmill" spray lubricant. It contains no solvents, petroleum distillates, or propellants that would harm the rubber. Should be in a 4 ounce bottle with a pump-action sprayer on top.[sm=thumbs_up.gif]

BoysToys

I run a Gates belt on my T-Rex 450 and care for it like Joe at Tech Model Products has advised. No lube at all and a little on the loose sid. My current belt has approx 50-60 flights on it and still looks brand new.

This is a quote from [link=http://helifreak.com/showthread.php?t=47807&page=3]HelFreak[/link] Post #26

--------------------------------------------------------------------------------

"We recommend the following for our Gates belt:

1. Do not use any lube. It's not needed and causes debris build-up which can clog the teeth.

2. Run the belt on the loose side. Too tight and the belt will overheat and self destruct.

3. Be sure the boom and tail shaft are aligned properly. It's important that the belt runs centered on the pulleys and not rubbing on the flanges.

4. Be sure the tail shaft bearings are good.

5. Be sure the pulleys are clean and burr free. Clogged teeth will cause the belt to slip and become damaged really fast. Burrs will grind away at the belt.

No belt can compensate for mechanical problems and this is usually the cause of short belt life.

Fiber (fuzz) build up is normal during the inital flights and should taper off with continued flights. Just blow it away with compessed air etc. The belts are cut from one large belt called a cuff. This exposes fibers at the edges which becomes the fuzz.

In a nutshell - Keep it clean, aligned and lube free.


Joe

www.techmodelproducts.com

BryFlyGuy67

Thanks!

alfredbmor

Boys Toys: Great info thanks for sharing!!

Bretuk

I removed the idle pulley and tried hovering for 2 minutes, the belt is not catching on itself on cross over inside the boom but can hear noise from belt running around the front and tail drive gear, I then put on silicon spray on belt and wow so smooth, free running everything is and quiet. The blades keep spinning much longer now after I have landed with throttle off.

QUOTE from http://runryder.com 'I went Align office in CA. The Technician told me that i don't need idler pulley, it doesn't give you any better but only problem, so I took that off since than.'

fossoman

What is the idle or idler pulley got a picture?
Fossoman

Tolla

I seem to recall the first posts regarding lubrication of the belt had nothing to do with lubrication of the belt at all but everything to prevent the build up of static electricity which was perhaps causing glitching with some radio systems.

The idler pulley is the small wheel at the top of the tail case. IMO it is there to push the belt down by just a little bit to clear the top of the tail case. I have removed my idler pulley to have a closer look and with the pulley removed the top of the belt definitely touches against the tail case connection screw that is located just in front of te idler pulley. This is an aluminium Copter X tail case. This may not be the case with all tailcase assemblies, I suppose.