Clutch liner replacement

[troasb]

Hi Folks!

I had a hot start and smoked my clutch liner. Green dust everywhere! It still works but in Idleup1 the rotor rpm is really down, in Idleup2 it works fine. But I understand I have to change it and have ordered a new liner. I have never changed a liner before so I am wondering a bit how to do it, what glue to use and so on. Any help and tips are welcome.

Trond

[Mark Dean]

Trond,
Sorry to hear about the hot start, but hey the good news is that its an easy repair.
There are many threads on here that go over the liner replacement. I have linked one for you and I think it will help you out the most.
http://synergyrchelicopters.com/forum/index.php?topic=3241.msg33103#msg33103
If this doesn't cover your questions, just let us know.

Mark

[troasb]

Trond,
Sorry to hear about the hot start, but hey the good news is that its an easy repair.
There are many threads on here that go over the liner replacement. I have linked one for you and I think it will help you out the most.
http://synergyrchelicopters.com/forum/index.php?topic=3241.msg33103#msg33103
If this doesn't cover your questions, just let us know.

Mark

Hi Mark!
Thank you for your useful information. I think I will use 30 min epoxy and electric tape to do this, Maybe I should order a replacement clutchbell with liner to have in my fieldbox for future mishaps.

[Mike Spano]

Trond,
Sorry to hear about the hot start, but hey the good news is that its an easy repair.
There are many threads on here that go over the liner replacement. I have linked one for you and I think it will help you out the most.
http://synergyrchelicopters.com/forum/index.php?topic=3241.msg33103#msg33103
If this doesn't cover your questions, just let us know.

Mark

Hi Mark!
Thank you for your useful information. I think I will use 30 min epoxy and electric tape to do this, Maybe I should order a replacement clutchbell with liner to have in my fieldbox for future mishaps.

I have been wanting to do this too. one for the N7 and one for the N5C. so I don't have to stop flying just because of the liner. I can replace, continue to fly, and re-line later.  that's a great idea!

[Cliff Chmiel]

When I used to fly nitro I would replace clutch liner and glue in with jb weld epoxy get soft  when hot

[troasb]

When I used to fly nitro I would replace clutch liner and glue in with jb weld epoxy get soft  when hot

If JB weld is used, will it not be difficult to later remove it for future liner replacements?

I hear that liners in rc-cars were glued with contact adeshive, that is much easier to get away later, but maybe not good enough here?

[Cliff Chmiel]

yes harder to remove but never come loose, never see jb weld fail

[Danny Dugger]

I just clean the bell really well with acetone and use 5-minute epoxy. Unless your clutch is slipping it shouldn't get that hot, and if your clutch IS slipping you probably need a new liner anyway

[Richard Rollins]

Save yourself some grief and use the 5 min or 30 min epoxy . I have an extra in my stash for each my N5C and my N7 for just in case moments but have yet to need to use them...

[flyalan]

I have toasted a clutch or two and like Richard keep a spare handy so I can get back in the air quickly. I have always used  quick set JB weld but any epoxy will do.

Cheers

Alan

[troasb]

Well, I have now finally relined my clutch. I didn't finished this job before, because I also needed a clutch assembly that took forever to come to me. I did as instructed and used 30min epoxy and the clutch assembly with two rounds of tape on as a guide and as pressure on liner while the epoxy dried.

But before this I had to sand down sharp edges and uneven spots on the liner and cut it to correct lenght. I put on epoxy on the clutch bell, put the liner in and pushed the clutch assembly with tape in.

When time was up for the epoxy to have dried, I checked and guess what had happened?! Of course I had put on too much epoxy and I had glued the clutch assembly firmly stuck in the clutchbell! Blargh! It was not easy to get loose and took its time as I had to be carfeul to not destroy the clutch assembly. When I finally got it loose I had to start on the job of removing excess epoxy. With Dremel, sanding paper and knife I finally got it fine again!

Next time, I wonder if I will take on this job again, yes I know, I am clumsy. I have to consider the job against the cost of a new clutchbell, and the easy way is of course to just buy a new clutchbell, though costly but it would be  a waste to throw away a perfectly good clutchbell just needing a new liner. So I think I will try one more time before I give up! Now I know I have to be very careful with the epoxy.

Trond
Norway

[troasb]

And now the clutch works just beautiful again!

[troasb]

Now, my clutch liner is gone again after some 100 flights. I guess and hope that the reason for this untidy wear comes from that I usually stops the engine by cutting off the fuel flow to the engine and the high rpm this puts on the clutch.

[Danny Dugger]

If you find yourself holding the head still often while the engine is revving high enough to engage the clutch then yes that would wear it out rather quickly. Also hot starts, full throttle autorotation bailouts from very low headspeed, revving the engine while holding the head, trying to spool up too fast before take-off, all of these are hard on a clutch. Basically you want the clutch slipping as little as possible to extend it's service life - no matter what machine it's in.
Why not set up a throttle cut switch to close the carb and shut it off immediately with the tx?

[troasb]

If you find yourself holding the head still often while the engine is revving high enough to engage the clutch then yes that would wear it out rather quickly. Also hot starts, full throttle autorotation bailouts from very low headspeed, revving the engine while holding the head, trying to spool up too fast before take-off, all of these are hard on a clutch. Basically you want the clutch slipping as little as possible to extend it's service life - no matter what machine it's in.
Why not set up a throttle cut switch to close the carb and shut it off immediately with the tx?

Yes, I will set up a throttle cut switch now, but I always run the engine dry after a days flying to preserve the engine as much as possible.