What's the best belt tension?????

[mewsikman]

I have looked everywhere for info on this and its all conflicting.....

This is the first heli that I have had a belt drive on so its very new to me, im use to torque tubes my opinion they are much easyer, appart from the one on the synergy...........

So could someone please give me the crash course on the best belt tension for the 500....

Many thanks in advance
Alex

[ckoelliker]

Mine seems to be on the tight side. If it starts to loosen, it will rub on the boom, and the vertical tail fin will wag.

[mewsikman]

Thanks for the info but im not ready to maiden it yet.....

still waiting for servos etc to come

[mewsikman]

Anything else that I can check on the bench before I test fly it???

[fireup]

Basicly if you push on the belt, it should flex in at about 20-25% relative to the other side of the belt. But if you turn the tail and hold the head and the belt skips easliy, then it's too loose.

[mewsikman]

Great thanks :)

[ckoelliker]

Also be warned that the belt can stretch (at first), slip (the tail boom), and change tension with extreme temperature changes. All though the last one has never happened to me, but it does not get very cold down here. But on the 500 the tail boom will slip. If it constantly is slipping you can usually put one piece of the clear packing tape around the boom to increase the od a little bit.

[psindrup]

Anything else that I can check on the bench before I test fly it???

Spray your belt with Graphite 33 (or silicone) before installing it, to avoid static buildup.

Peter

[Prophet]

half past half

[mewsikman]

Hey guys,
Just dropped the main shaft and gear in and spun the blades by hand.......... I counted it an it took 8 sec before the blades totally stopped.... Does this mean that my belt is a little to tight??? or is it just right?????

[warpspeed]

You can get kind of a 'feel' for it by how it spins-but I'm not sure if 8 seconds is good or not. Like Prophet mentioned, you should be able to push one side of the belt halfway past half, or 3/4's of the way to the other side of the belt. With the 500 you need to make sure the belt's not so loose that it rubs on the nub in the boom block.
Really they're not that picky about it-as long as it's not too loose or too tight it will be ok. You'll get a feel for it over time.