Clutch wear on a Nitro

[Crumpet]

So after putting 2 tanks through my 700n dfc/105hzr following tuning advice on here (thank you guys!) I probably spooled up the heli 7 or 8 times.

At the end of the 2 tanks I noticed a lot of this powdery blue/green stuff which I assume is the clutch liner.



Is this more than expected?

I cant find anything in other threads on any forum about this and thought its better to ask incase there is a preventable problem there.

Martyn

[waveydavey]

Looks like the gap is too big between the clutch and the bell and it's having to open too far, be careful that can cause the clutch to snap

[Ryan-Henson]

Clutch has been slipping and worn the liner out.
Initial gap between the liner and clutch was too large causing the clutch to slip early on, and increase the wear, hence the blue dust.
If you can find some black clutch liner, that would be a better bet. The blue liner does wear very quick unless the gap between clutch and liner is really spot on.
When installing the new liner, apply glue, insert the liner, wrap one layer of electrical tape around the clutch and insert into bell, this is the basic way of getting the gap reasonably close, without the use of a lathe etc. once dry remove clutch.
When you take the old clutch out, check to see if the clutch shoes have spread apart, (due to the over large gap between the clutch bell and shoes) if so, the clutch will also need replacing

[Crumpet]

Oh poo. Thanks for the steps. I'll start with working out how to get the engine out. I'll update lol

[yuppyflyer]

Agree with above advice from Ryan, you need a close gap from day one on this model.

[Crumpet]

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So Im a bit stuck with getting the clutch bell out. Ive taken the two grub screws off the top where the starter goes and taken out that shaft but still cant get the bell out. It looks like theres a bearing i need to get it off. Any ideas? Do people just fit the new liner while its still in the heli?

I'll resume tomorrow

[Flat Eric]

You can fit in situ but it’s easier out on the bench. I used to slacken the frame screws enough to separate them & drop the clutch stack down.

[waveydavey]

So Im a bit stuck with getting the clutch bell out. Ive taken the two grub screws off the top where the starter goes and taken out that shaft but still cant get the bell out. It looks like theres a bearing i need to get it off. Any ideas? Do people just fit the new liner while its still in the heli?

I'll resume tomorrow

You can't get it out like that without dismantling the frames, or at least one side. The grub screws are for teh starter shaft only. The clutch stack housing has 2 bearings and seats for the so needs splitting. What you can do is remove elevator aor aileron bellcrank arm and loosen the frame screws enough to wedge the frame open enough to remove the stack. Once the stack is out use a hair dryer and lightly warm the bellcrank, this will loosen the adhesive enough to let you pull it out. Lightly sand and then clean with IPA before you glue the new one in with 2 part epoxy. Remove the clutch from the top of the engine wrap a layer or 2 of tape around it and use this to seat the new one into the bell, or buy a new one, replace it and repair the current one when you get a mo.

[Crumpet]

So I had an issue I wasnt expecting. Nowhere in the UK seems to have liners. Apparently the 700XN clutchbell is a straight fit and comes with a pre-installed liner. My midland helis says its fine so thats whats in the post

[Guest]

Isn’t the 700xn a steel liner? Few threads where people have chosen to take that out and go back to the previous N. Question over heat and slippage.

MJ

[Crumpet]

It arrived. Its black and doesnt feel like steel. However, as it comes preinstalled you cant adjust its gap to the clutch. I wrapped electrical tape around the clutch once as instructed above and theres 1mm gap all the way around still. So not as tight as it would usually be. Ive checked and the 700XN uses the same clutch, and on the part finder website under 700n dfc it actually lists the XN clutchbell when you click on the liner. Im thinking it might be superseding the liners as nobody as them

[Guest]

Ok that’s a surprise. The XN kits def have/had a steel liner clutch bell setup. Maybe Align has address it already and gone back to the previous setup. I fly Align and tend to swap the clutch over to Lynx they are marginally larger with more contact area due to there design. If your gap is right the stock should be fine though. Some liners do wear at a greater rate, there have been several different materials with Align as well.

MJ