is my clutch dying?

[choppaholic]

hi all, need some help please,

my 600 N is behaving very odd, some time i get lift off some times not..... even at full throttle.being new to nitro i can't tell if its the head speed/clutch gone.

i can see the swash move up to its full travel so doubt its the pitch, my pitch curve is linear and have 12+- spot on.

what puzzles me is it was ok for the 1st 5 tanks i did on it, then it started doing this, then i burnt my engine so now i have a new one. this one yesterday was fine but today is doing the same thing.

the heli is seconds hand is my clutch dying. is the only thing i can think of..

also when it does lift off the climbe is very slow. sometimes it behaves fine sometimes no. i tried to lean the mixture by 5 notch still no go.

i did get the engine started at full throttle with the head in my hand once so did take a bit off the life of the clutch, but was for only like 5 seconds before i put throttle hold
any help please....

[tonystevens]

it might be worth checking that your prop nut hasnt come loose if youve got your engine out to check the clutch.it could be slipping on the fan mount.worth a look

[Mike W]

sounds like the clutch liner has/is gone/going .. time for a new one .. or you will be buying a new clutch as well ... only a few quid these things as well ....

[jamiem]

if the engine is running very rich, it could be backfiring causing it to run in reverse, ive had this happen a few times before now. Otherwise, drop the engine and check the clutch and liner for wear

[GravityKills]

usually the clutch can take some abuse. I find it hard to believe (but, everything is possible).

Note: You can smell a slipping clutch. You'll know it when you smell it :-)
It also gets hot. You can feel the temperature underneath the tail drive gear, there is enough space.

[choppaholic]

thanks guys, i will just strip it out and see whats happening. but any more ideas please let me know. thanks again

[choppaholic]

i changed the clutch liner, it was hardly worn, the new liner is better, but i still have the same problem any more ideas guys. i will strip the engine out to night but i dont know whats happening, there is hardly any lift. no clutch slip smell some times i can rev it to its max rpm without any clutch smell and the rotor not even spinning. this is driving me nuts . please help guys .

[squeaky pete]

If u can rev it up with nothing moving then its defo running backward, silly question, hav u got the oneway bearing in the main gear the right way??

[jamiem]

The one way could be slipping, def worth checking. If you hold the rotor head, can you turn the main gear anti-clockwise? It should be locked.

You mentioned you changed the liner, but what about the clutch itself? How did you glue the liner in and check for clearance against the actual clutch?

[Steve]

Could also be tired servos or a weak battery pack maybe - failing under load or not holding their position.

[J-S-Q]

If u can rev it up with nothing moving then its defo running backward, silly question, hav u got the oneway bearing in the main gear the right way??

Yes, sounds like the engine might have started running backwards. I would have also said to check if you have the one way bearing in the right way up but the fact that the rotor head is sometimes spinning up suggests that you do have it in correctly.

[choppaholic]

its definitely not running backward, once it starts to slip, if i let idle for a few seconds and then throttle up it starts to spin the rotor. the bearing is in the right way. i used titanium mix epoxy to glue the liner its good until 150 degrees C. i didnt actually check the clutch and gap what should it be, the only thing i can feel is the clucth is slipping on the crank itself as suggest before, engine out again

thanks guys.

[Steve]

its definitely not running backward, once it starts to slip, if i let idle for a few seconds and then throttle up it starts to spin the rotor. the bearing is in the right way. i used titanium mix epoxy to glue the liner its good until 150 degrees C. i didnt actually check the clutch and gap what should it be, the only thing i can feel is the clucth is slipping on the crank itself as suggest before, engine out again

thanks guys.

An easy way to get an engine to run the right way after it has started backwards is to let it idle for a few seconds then throttle up - the engine jumps into forwards running. So, you could still be starting it backwards due to rich needle settings or any other reason, trying to take off ..... nothing happens, blades don't turn, then bringing it back to idle for a few secs, then throttling up ...... engine jumps into forwards running, and hey presto, it works.

[steve b]

hi Having the same probs with my t rex 600le
took it out to day for its first flight ,started the new engine up Ys 50 st that started up sweat ,let it idke for a bit and then took the revs up. Head not spinning
turned off and re-started agian same probs ,i thought the engine was running backwards
any way tried that 5 times i can't believe its running backwards every time
checked the gears with my 700 all seam to be turning right . take the revs to 1/2 throttle and the head startes to spin up but more rev than headspeed
removed engine and checked the clucth ,put the clutch in the bell and checked the clearance there is quite a large clearance 25 thousance of a inch
any way removed liner a fitted a new liner from a sceadu will try it again tomorrow

[Jamin_00]

Tony can check it over for you if you both coming tomorrow ?