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Thrashaero
02-28-2009, 09:50 PM
Many of you have noticed that the belt tends to shed string material, along the sides.
>>This is not the only problem.<<

I noticed a tiny clump of string sitting between a couple of teeth. thinking this was just a clump of small string debris that got stuck onto the teeth like i had rubbed off once earlier, trying to remove it I saw it was actually still attached to the belt, between a pair of teeth. Since the string's purpose is to keep the belts tension firm and strength backbone, I tried stretching in that area and sure enough saw the teeth spread quite a bit and the backside of the belt narrow. >>The whole set of fibers that run through the belt were completely snapped in this one area, leaving only the rubber to keep it together.<< Other areas there is no stretching of course.
This could definitely result in a snapped belt and might even get caught in the gears (or knotted up inside the tailboom) from the snap. Either way, not pretty.

So those of you who keep trying to pull the boom back because the belt isn't staying tight, might want to check this before you stretch it to the point it will snap even easier.
How the inner surface was broken and the whole set of fibers were severed at once, is something that should be looked into as this isn't just an inconvenience but a catastrophic failure.

I wonder if any of the hard 3D pros have ever ran into this or they just have the luck of it working 100% perfect all the time. My luck with belts in general is terrible. especially the damn teeth!

gixxerjeff
02-28-2009, 10:45 PM
You should have a look at your belt as it exits the tail shaft housing.there is a rectangular shaped hole that can have burrs that catch the belt sides.I cleaned up mine with a needle file.No more strings.My previous belts would seperate like your describing......

OICU812
03-01-2009, 01:46 AM
I hope TMP makes or gets ahold of those Maverik belts like they had for the 450, those truly are the best belts for the 450 and they would work fantastic for the 250 as they are a semi yeloow rubberish compound and do not shred and they do certainly last!

Thrashaero
03-01-2009, 02:36 AM
You should have a look at your belt as it exits the tail shaft housing.there is a rectangular shaped hole that can have burrs that catch the belt sides.I cleaned up mine with a needle file.No more strings.My previous belts would seperate like your describing......

well i'm not sure if you're talking about the same thing. I edited my post to basically say the following; i was mentioning the typical problem of fibers coming out the sides of the belt (where the housing would scrape with burrs) though this is not the particular problem I'm referencing but to just say it's not the only belt problem. I was also going to file down the housing as I read your post about that earlier. But I was just in the process of removing that side-fibers problem when I happened to look at the teeth..there was an exit of fibers between a pair of teeth. it seems the whole set of fibers through the width of the belt were snapped and poked through somehow. this would be more along the lines of perhaps a sharp tooth on the gear cogs (or maybe a scrape of the tail blades on the ground, causing a fast stretch or cause the cogs to dig deeper perhaps). but i'm using plastic gears. really a strange problem and can cause a huge problem if i never thought to look there.

caseyjholmes
03-01-2009, 09:40 AM
i was mentioning the typical problem of fibers coming out the sides of the belt there is screws in the tail that can rub the side of the belt too.

That's odd the belt is snapped on the inside..
It would be hard to check if your pulley teeth were sharp.

Whatever you do,
don't pull the fibers out of the belts. Just leave them. Don't burn them off either. And make sure it is well lubed.

PlaneHeli
03-01-2009, 11:01 AM
Many of you have noticed that the belt tends to shed string material, along the sides.
>>This is not the only problem.<<

I noticed a tiny clump of string sitting between a couple of teeth.

I had the same thing after only 35 flights.

No hard 3D.

Im not sure if it was due to the belt being Too Tight or Too Loose.
Some said they thought is was caused by a loose belt. It appears the belt 'teeth' look OK though. So I wondered if it could be caused by the belt too tight. (IE: The tip of the pinion rubbing the threads).

I mentioned it here in this thread.

See my post #17.

Is this what you have

http://www.helifreak.com/showthread.php?p=1129670#post1129670

Kam Arrow
03-01-2009, 12:11 PM
I have had the same thing on my first belt, kept pulling the boom out to tighten it and never got any tighter.
I had heard there was a burr on the tail drive pulley that was causing the side to fray and I cleaned that up but this was inside the belt like the OP.

Bill

Thrashaero
03-01-2009, 01:02 PM
I had the same thing after only 35 flights.

No hard 3D.

Im not sure if it was due to the belt being Too Tight or Too Loose.
Some said they thought is was caused by a loose belt. It appears the belt 'teeth' look OK though. So I wondered if it could be caused by the belt too tight. (IE: The tip of the pinion rubbing the threads).

I mentioned it here in this thread.

See my post #17.

Is this what you have

http://www.helifreak.com/showthread.php?p=1129670#post1129670

Yes planeheli that's exactly what I've got going on.
Though in that post you say tension is ok, however for me the tension is completely gone in that area, very stretchy and gets real thin in that short area. i forgot to think about pics.

PlaneHeli
03-01-2009, 07:39 PM
Thrashaero

My belt tension was OK. It may be hard to see in the photo, but all the belt teeth still looked OK. If the belt was loose I would expect the teeth to be worn or stripped in places.

I still dont know what caused it.

heli-on
03-01-2009, 09:15 PM
If you consider how fast that tiny belt is turning (higher than any other Align heli -pretty darn fast), I'm actually kind of impressed with the belt. It's certianly light years ahead of the 450's stock belt.

FWIW, I run no lube and don't have belt issues. The tension has to be spot on. If you ave to adjust your belt more than 3 times, I'd say that's over tighening it causing it.

If your boom is slipping then shave each half of the block and shorted the auminum spacers for a tighter squeeze.

PlaneHeli
03-01-2009, 09:53 PM
heli-on,

Yes, Im trying not to overtighten it this time and see how it goes.

Thrashaero,

If the belt tension is gone, maybe that indicates the threads inside the belt have completely worn through. I assume without those threads inside the belt, it would stretch significantly, as the belt is a very thin strip of rubber.
Just a guess though.

mickeyjohnston
03-06-2009, 09:21 AM
Last weekend my belt snapped. The tail spun hard and I was able to level off the heli. Once I did that I hit throttle hold and down she came. Atleast now I can say I tried a auto with a 250 at 25ft. I ended up breaking the gear.

Keep an eye on these belts. I probably had 50 flights on it.

helidude3
03-06-2009, 09:19 PM
I don't tighten mine very much, I can turn it about 1/8th w/o the main gear moving.

cbrian4
03-06-2009, 10:31 PM
Well during a second pack two days ago the tail was acting funny. Then i tried to tighten it but it kept stretching, then i found huge clumps of threads. Good thing i caught it before it snaps.

nitronuts
05-05-2009, 02:33 PM
Many of you have noticed that the belt tends to shed string material, along the sides.
>>This is not the only problem.<<

I noticed a tiny clump of string sitting between a couple of teeth. thinking this was just a clump of small string debris that got stuck onto the teeth like i had rubbed off once earlier, trying to remove it I saw it was actually still attached to the belt, between a pair of teeth. Since the string's purpose is to keep the belts tension firm and strength backbone, I tried stretching in that area and sure enough saw the teeth spread quite a bit and the backside of the belt narrow. >>The whole set of fibers that run through the belt were completely snapped in this one area, leaving only the rubber to keep it together.<< Other areas there is no stretching of course.
This could definitely result in a snapped belt and might even get caught in the gears (or knotted up inside the tailboom) from the snap. Either way, not pretty.

So those of you who keep trying to pull the boom back because the belt isn't staying tight, might want to check this before you stretch it to the point it will snap even easier.
How the inner surface was broken and the whole set of fibers were severed at once, is something that should be looked into as this isn't just an inconvenience but a catastrophic failure.

I wonder if any of the hard 3D pros have ever ran into this or they just have the luck of it working 100% perfect all the time. My luck with belts in general is terrible. especially the damn teeth!


Thats exactly what happended to mine today:thumbdown: I only have about 25 flights, mostly indoor hovering and only a few outside. I noticed the tail was twitching on my last flight, flying figure-eights around the yard. The first thing checked was the belt and it was really loose. I tried tightening it but the boom would come all the way out of the holder, so the belt was streching like a rubber band.

Is there an aftermarket belt yet for this heli?

specialk
05-05-2009, 07:52 PM
are there burrs on the plastic tail boom holder or the metal one as well? I am wondering if going to the metal one will help the issue. I am running a plastic front pulley, metal tail pulley, plastic tail boom block and no lube with no issues to date

helidirect
05-05-2009, 08:16 PM
Thats exactly what happended to mine today:thumbdown: I only have about 25 flights, mostly indoor hovering and only a few outside. I noticed the tail was twitching on my last flight, flying figure-eights around the yard. The first thing checked was the belt and it was really loose. I tried tightening it but the boom would come all the way out of the holder, so the belt was streching like a rubber band.

Is there an aftermarket belt yet for this heli?

We have some new belts coming for test now.

www.helidirect.com

helidirect
05-05-2009, 10:46 PM
here is the one that made from Japan very high quality, we will test soon.

559T

heli400
05-06-2009, 02:40 PM
Helidirect,

Let us know how those belts turn out:thumbup:

I'm interested in getting some of those belts.

Rick

nitronuts
05-06-2009, 03:25 PM
here is the one that made from Japan very high quality, we will test soon.

559T

Nice, Ill be the first in line for those:lol: Really disappointed in the quality of the align belts:arggg:

JimRC30
05-09-2009, 10:08 PM
This is exactly what happened to me today on a brand new belt. My belt was yellowish in color as described in an earlier post. Went up to fly and heard a noise coming from the bird so I set it down for inspection. Sure enough the belt was very loose. Since it was new and went on tight at first, I assumed it was just loosening up. It was about the third flight on it. So I tightened and sent it back up. Very poor rudder response and noise so this time I inspected further only to find the symptoms described in the original post.

Now again this was a brand new belt and all I do is keep it lubricated with Liquid Wrench Silicone Spray. Could this stuff be degrading the rubber?

This video shows what the belt looks like:
YouTube - RC Heli Belt Failure

Jim-

Thrashaero
05-10-2009, 10:51 PM
strange looking belt. as far as the yellow teeth and the clear-plastic and black threads.

with stock i've only seen the yellow threads, opaque black plastic.

but the action of it stretching is exactly what i was referring to in original post.

anyways, since I have doused my belt in food-grade silicon spray. this stuff smells/feels very inert/safe. perhaps why it's food-grade. it doesn't have that industrial/machine-shop smell to it like the liquid wrench stuff does. i just use that on metal parts.
my guess is that the liquid wrench spray is inverting the colors of your belt...weird. along with that, probably degrading it.

so i had a crash recently, the one-way bearing was completely stripped and i could'a swore the belt was done for as well. it's good as new (minus some shedding on the sides). even feels slick as when i first put it on about 30 flights ago. i used like 2 or 3 coats of the food grade spray. i have a plastic drive gear and a metal tail shaft pulley.

JimRC30
05-10-2009, 10:55 PM
since I have doused my belt in food-grade silicon spray. this stuff smells/feels very inert/non-degrading. perhaps why it's food-grade. it doesn't have that industrial/machine-shop smell to it like the liquid wrench stuff does. i just use that on metal parts.

I will definitely have to check out the food grade silicone. I have read that others use the liquid wrench but I agree, it has that "WD-40" type smell which worries me.

Where did you happen to pick up your silicone?

Thrashaero
05-10-2009, 11:39 PM
I picked mine up at one of those Do-It Best stores. I think that's the name. It has the hammer inside the D on the logo.
a lot like a true-value hardware store. The brand of the spray is CRC and comes in an all-green can.

ndoren
05-11-2009, 12:03 AM
I'v'e heard that some use silicone shock oil designed for RC cars. Pretty inert and non-corrosive and non-petroleum.