bloody thing!!

[Delarado]

So as you may or may not know, I have the 700N DFC from align with an OS105. Its had about 2 gallons of fuel through it now with varying states of tune, I haven't really got to the stage yet where I feel like I can "Just fly it" because ive been very cautious with needle settings.

Anyway, I Went out today with the intention of putting in some time on the high needle setting. Fuel is optipower 20% with an OS #8 plug and the standard shim (I haven't pulled the engine apart - I'd welcome comments on if I need to put a shim in or not because I need to pull the engine out now)

So anyway, settings at the start were mid half open and high 2 turns open (I closed the mid from stock setting of 1 full turn open as it wouldn't even spool up properly with it and I burnt a clutch out!)

Up I go to do some really agressive tic tocs, as per bert kammerers engine tuning video. Engine bogging so hard it feels like its going to stall, but plenty of smoke and no strange sounds. Recovers very quickly when you take the load off. I bring it in, lean it 2 clicks. Up again I go - seems a bit better, but still bogging really heavily with hard pitch.

So, I bring it in, lean it out another 3 clicks or so and up I go. Seems like more power now, but the engine seems to be making funny high pitch noises during the transitions. I bring it in, with the mantra "If in doubt, richen" in my head.

I richen it up 3 clicks (Back to where it was) same as before now - just loads of bogging. So I bring it in again and lean it 2 clicks this time. Up I go, then the engine just goes crazy halfway through a tic toc, screaming away RPM wise. Clutch? Anyway, I hit throttle hold and auto it down.

So yeah, seems its eaten another clutch. Not sure what happened to it - I'm about to pull it apart. My best guess is I didn't fit the replacement liner properly somehow. As I was leaning it and it was gaining power the clutch eventually just let go...

Anyone else having any issues with these clutches or any tips? Last time when I fitted the new liner I used a slither of paper between the bell and liner and a light smear of araldite to fix both of them in there (Smeared the bell, put the paper in, smeared the paper, put the liner in)

Annoying thing is what I had to land on, and the result!

[Delarado]

bloody thing!!

[Delarado]

Also, my vbar logs show "governor input has glitches" constantly. What does this mean and whats the best way to sort it?

[ghost2212]

Welcome to the world of nitro :P

[Tommy]

The 105 has awesome power and yes it finished off my clutch liner in my Avant, the liner was a fair few years old (prob 4 or more)

If you haven't fitted the liner properly in your 700 as you say that is probably the cause and the 105 has also told your clutch where to go in conjuntion with taking your liner apart

Araldite does not have as higher temperature resistance as say JB Weld

You need to get a perfect fitting of the liner otherwise it will happen again

[Obi Wan]

OMG - Deja Vu!

I'm new to Nitro - but have recently got the new 700N DFC with the OS 105 with Vbar. I've had about One & Half gallons through it. This weekend with some of the more experienced Nitro Flyers in my club - the engine has been slowly tweaked/tuned, but I kept losing power and then eventually it would not take off. After much head scratching - we realised that the clutch had failed / burnt out. I did not check the Vbar log.

I've bought all the replacement parts and hopefully will have them in soon. I'm obviously concerned if it happens again.

Paul

[jwatts007]

I have a old 700 with a ys 120 fitted and the clutch is fine burnt my 1st one out with a hot start...one of the things that does the clutch is taking off with out enough revs thus not engaging the clutch properly and allowing it too slip...the clutch slips on the liner which makes hot and shiny doing this over and over and the clutch goes...let the headspeed get up to speed and the clutch engage while the heli is on the deck if need be adjust the throttle curve to give you more revs for take off...I do get sensor glitches but as my headspeed is changing in idle ups thats good enough for me...I never touched a 105 but doing full power climbouts I find best for tuning the high end continuous flips for the mid......

[mc_clean_david]

I had a similar issue with a TREX 700 - I had to change the clutch and liners for the extra torque as I went through 3 clutches and 4 liners within 3 weeks! I changed to LYNX clutch which as a bigger contact area when it engages and a LYNX carbon liner and it has never give me any more issues. I got both from Fastlad

[1chris]

The way I replace my clutch liner is as follows

Remove all traces of old liner, Cut new liner to size, Wrap approx 2 layers of electrical tape around the clutch, check the fit with the liner and clutch insitu, adjust untill it is a nice tight fit, mix up some 20min epoxy, smear it on the bell housing, Insert the clutch liner into the bell housing, Insert the taped up clutch into the bell housing, leave to set, remove clutch when dry, remove any traces of glue with sharp knife, now all good to go and assemble back in Helicopter, never failed yet

[mc_clean_david]

When fitting a new liner I always roughen the inner of the bell with a dremel - just put a few marks on it to take the shine off it. Then get your clutch and put sellotape around it and make sure it goes round at least 3 or 4 times. Mix up 30 min Epoxy ( I used Z Poxy as it seems to be the strongest) and put a fine layer of it onto the inner of the clutch bell. Push in the liner and get your clutch, which as been wrapped in tape and squeeze it into the clutch bell - if it isn't a tight fit put another layer or 2 of tape on and retry! Leave to set for 1 hour or even over night then remove the clutch, remove the tape and fit to heli.

Remember to use electrical contact cleaner or clutch cleaner etc to remove any sticky from the clutch before using!

[Delarado]

Annoying, Ive just written a reply but lost it.


The clutch liner here was 5 or 6 flights old... So that shouldnt be a problem. I forgot to mention the clutch seemed to be ok once I'd landed - If i throttled and held the head it'd try and spin. Maybe the liner is spinning in the bell? I can see the join with the engine out so I'm going to mark it and see if it moves. The clutch looks ok - so not sure what was going on.


What would you recommend to fix the liner? I did check the temp of the clutch bell when it came down (I figured if it was slipping then it'd be really hot) but it was only 18c. It is very cold out though...


Anyone have any experience with the quick uk heavy duty clutches? Might think about an upgrade if this is going to keep happening!


Any recommendations on a shim to use? The manual says 0.1mm for 23% and 0.2mm for 30%. I'm using 20% and don't have a shim - should i put one in?

Thanks for the fitting tips on the clutches, I never thought about letting it dry with the clutch inside. Im pretty sure I just stuck mine in and left it without the clutch inside, will be worth doing the tape thing.

[Gixxer]

Check that the fan isn't slipping on the crankshaft.

[Delarado]

I did think about that. Is there a way to do it without undoing everything?

my clutch liner is quite shiny so maybe its just slipping.

[mc_clean_david]

I was a bit warey of leaving the clutch in the first time I tried it, but it worked perfect - just make sure you don't put too much epoxy in as it might push out and stick the clutch as well (this is why tape is used , so you can push the clutch and if the expoxy has pushed out it will stick to the tape not the clutch and it can be trimmed with a knife or dremel)

[Planehazza]

The way I replace my clutch liner is as follows

Remove all traces of old liner, Cut new liner to size, Wrap approx 2 layers of electrical tape around the clutch, check the fit with the liner and clutch insitu, adjust untill it is a nice tight fit, mix up some 20min epoxy, smear it on the bell housing, Insert the clutch liner into the bell housing, Insert the taped up clutch into the bell housing, leave to set, remove clutch when dry, remove any traces of glue with sharp knife, now all good to go and assemble back in Helicopter, never failed yet

That's what I do too