Hi,

I've been setting up my raptor 50. Have epoxied the liner correctly to the bell, and the clutch is well secured to the engine shaft with
prop nut + Loctite. I have aligned the two properly with loose motor mount screws and starter cranking. After starting the engine, I can't get the clutch to engage the bell/main hear. I mean as I increase the throttle to say 25%, even then no driver.

So I was wondering at what throttle I/p should the clutch engage and drive the main gear?

Alos I see the pinion - main gear mesh is tight, unlike 450/500 - is this normal

Regards
skbg

Pinion-main gear mesh should be just like another heli, smooth. Either alignment prob or the clutch liner is too thick...Looks more like an alignment problem coz if the clutch liner is thick it will engage the main gear with initial spool up.

At what point does the gear gets engaged? 25% stick position is not an issue as such.

Also, which engine are we talking about? There is a washer just below the Fan. In one case the washer is not to be used i.e RL 53 or O.S 50..Dont remember exactly, will find out.

Also, check the Fan locking nut. If it has become loose, the whole assembly will be stuck/tight.

N read the Raptortechnique.com

Hi
Thanks - the liner seems ok, stuck it just the way it was in the manual.

W.R.T alignment - I initially had problems when the clutch would engage by default even at startup and idling, I thought that was bad.
Later I loosened all engine mount nuts and cranked the engine through the starter shaft and then tightened them back one by one until
there was no engagement of clutch when I crank and at idling. Hope that's correct. When I look from side I see the clutch is flat inside with the bell, neither hanging low or pushed up rubbing against bell.

I use RL-53H, and not using the washer. Thanks.

After you mentioned, I did take out the engine-clutch assembly and inspected the prop-nut etc all are tightly seated with Loctite.

The pinion-gear mesh is tight - not sure, it's not adjustable, so waiting to give it some runs so they set. Not until the clutch engages

Will try to see at what stick pos it engages, I did notice it does engage when I throttle up slowly building up rpm's, but seems to disengage even if I continue to throttle up, that was what confused me.

Help me troubleshoot pls.

Regards

We at our field always have to sand down the clutch liner. We have raptors in our field n sanding down the liner used to eliminate this problem. Also, check the starter shaft n main shaft for any bends.

If u test fly record a video if poss n if u hear anything abnormal dont force it..

How do you check the alignment between the pinion n main gear? Using paper or what?

Not sure I have to sand the liner since it's the opposite that's happening. How do you align the clutch with bell and starter shaft system? I won't be flying this anytime soon, i'm not yet confident with the machine, until it's predictable.
Will send a vid soon as I do.

Nope, not done the paper test, since there's no mesh adjustment ever possible on this. But if I try to force rotate the spur gear by thumb, it's not like on rollers, it's tight but turns for sure. But I  could hear a squealing noise when ever the clutch did engage and pinion drove the main gear. Note i'm testing with no rotor head assembly, just the main shaft, so no head mass to help.

Is the meshing tight even after you remove the engine?

Also, check the OWB

Which OWB, clutch or main gear? both are brand new out of box and seemed ok, no slop, not broken.

And Yes, even with the engine out it is tight fit. I have heard they do ease out if you let them eat into, but i'm not able to engage the clutch, so unable to do that.

on raptortechnique.com, what does this mean
"engine alignment - I use the start coupler to tell me if the engine is aligned. When you rotate the start coupler counter clockwise it should spin with little to no resistance" - little or no resistance, does it mean when you crank there's no clutch engagement absolutely, or some engagement, but just so little. And will this mean the clutch is centered with the bell, starter shaft etc?

At what point should the clutch engage, with a linear curve 0-25-50-75-100 ?
I feel the switch from electrics to nitro probably is still soaking into me - cos I tend to drop the throttle (like a fuel vehicle) unlike electric holding it there once off ground , will do a re-run today and see at what point it tries to engage

You need to replace your liner as the squeeling sound comes when the alignment is not correct ensure the following

- Engine properly seated
- clutch bell proplerly aligned
- Main gear Vs Pinion play should be there similar to 450 size and do the paper test.

Head mass doesn't affect this. Normally clutch should engage at 15% throttle.

Hellyflyer

What throttle curve r u running? Have you done the throttle calibration as described in raptor technique? Please post a pic of the throttle linkage arm at low, mid n high position as i doubt it comes linear curve.

In my opinion head mass will affect the clutch engagement, as without load it will not engage early...

15% throttle is too early for clutch engagement but it all depends on the set up...

Since, u said that the assembly is tight even after removing the engine so there may be a prob in the two shafts itself...

Do check the gap between the clutch n the liner..0.2mm is taken to be ok..

If he has placed the clutch liner properly, the liner itself will have no affect on the alignment

I see the points - I agree, the liner is well seated, new and has no wear out whatsoever. I took your advise anyway, did remove the engine and clutch assembly to check the clutch bell, all's fine, and no signs of metal to metal contact. My guess is the noise's from the meshing.

Ok, now some good news (looks like sometimes it just needs a day to start working ) - I put back the engine, re-aligned as before i.e. loose nuts and cranked with starter and then tightened them all. Now it seems to want to engage at about 5-10 %. The meshing still seems tight, but will have a few runs tomo to see if they ease out.

Is white silicone grease on the mesh good/bad?

Also, I haven't changed the low needle mixture, it is in factory setting (flush with the casing) , does this need any setting?

Doctor - I have set the throttle with both servo and throttle arm at mid-stick and for fully-closed pos (EP) and fully open position, and ensured no binding.

During ur test run please use the main blades n the canopy also.

We in our field have never used any grease on the meshing.

During break in for few initial tanks u dont need to change the  LSN setting... Start leaning out the LSN after you have leaned out the HSN n deres no increase in power. For LSN use 1/16 of turns during break in..For me RL53 is a finicky engine n even a small change will cause the temp to run high..

I have had problems with RL 53 during break in..So, had to fiddle wit the hidden needle. But, please dont mess with the third needle directly.

Deres a good thread on RL 53 here in the forum..I used as many as 8 tanks for break in.

Best of luck budddy n let us know how it progressed

Ok, no fiddling for me, i'm more than happy to see things started to work firstly ...will tae my time setting this thing up. And thanks for the help so far guys, nothing like shared experience.

Will update this thread as I make progress. The sound of the nitro engine is quite intimidating though
TNX

RL 53 with high flow 3d pipe makes a lot of sound. It works  best with that pipe..Also, make sure to check the hex nut inside the throttle lever..It may bcome loose n slips. Thereby, the initial carb setting may get disturbed.

One more tip: Heat shrink the locking pin of the tail shaft. In my case it bcame loose in betwwen a flight n broke the whole tail case. My futaba 9254 servo got locked at an end n the motor got burnt.

Its a powerful engine, keep raptor at a safe distance.

Yes It is quite load with this pipe.
have tightened the hex nut inside the lever, not sure if I should Loctite that or just tighten it?

All points taken.

One more thing, what kind of tool do you use to snap the e-ring onto the pin (in the tail pitch control link section)? I'm worried if it will break if done the wrong way.

w.r.t C.G, I fell I'll have problems as it's probably going to be tail-heavy anyway - how to achieve CG here?
I'm using a 1800mah 2cell 7.4v lipo.

Well I am happy that things started to work. Our doctor sahab is an expert on nitro setup.. I am glad he lives close by to sort things out once i get my rappy in the air..

Arey bhai, woh shubh din kab aayega jab aapka raptor havaa sey baat karega???

Any update?

Doctor sahab ...pretty soon 

I'm now tuning the engine, have faced few issues, kindly see this thread and suggest http://www.rcindia.org/helis/rl-53h-tuning-issues/

What problem are you facing with the engine?

I cannot access the link you had posted.

What fuel composition are you using? RL53 is a bit tricky engine to tune. Even small clicks on the main needle will affect the engine temperature a lot.

Keep the HSN rich during the entire procedure just to be safe.