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Heli engine tuning.

Started by gauravag, April 19, 2010, 11:13:26 AM

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murcielago

Satish you can also get in touch with Sharma sir (second chance) and Laxman. Both of them have wide experience in tuning engines. Particularly, Second chance who loves RL53 engines.

Laxman is our fields Yaaron ka yaar.

Back to topic: waiting to hear ur progress.

Ahmad

Doctor is the guru with RL engines

murcielago

Quote from: Ahmad on August 20, 2013, 04:19:57 PM
Doctor is the guru with RL engines
Yeah, thats why busted the RL engine.

satishkbg

Ok, had a first run today from where I left last weekend. After tiny adjustments I'm here
- The HSL is leaned out from 3 turns (open from fully closed) to 2 1/4 open now : the mid-to top seems to respond to I/p much better now. On the ground (without main blades) when I did a punchouts though the low to mid transition was sluggish, the mid-to-top end was better, with lots of smoke, and even oil dripping from exhaust. I checked the back-plate temp, they were on warmer side.
- I then left the HSN there and leaned LSN 1 hr at a time until I got a better (not 100%) response. There still seems a little hesitation at mid-to-mid+, post that the HSN comes into play.

One thing I faced on punchouts was the muffler gasket gave way resulting in loose muffler (happened 3 times on 3 new gaskets). I guess that's a common issue. I have got rid of gaskets completely and testing with anabond rtv silicone, it seems to do wonders. Have to wait to see how long it lasts, so far it's pretty good.

Question is
1. How lean can HSN be set on RL 53H? What's normal and what's not?
2. LSN? leaner is better or richer? I started out LSN flush : it simply would do brawwwwrrrrrbraawrr upto mid upto HSN taking over, so I have been leaning it , now 3 clicks/hours leaner. But I noticed the exhaust diminish just before mid and that's here i'm having the slightly sluggish transition, rest of the upper seems ok.
    Temps on 20-30% throttle : just hot, can touch for 6-10 secs.
3. Lean LSN further?
4. Should low-to-mid transition be smooth like linear or is it normal to have slightly richer feel?
5. NOTE: I have done the hidden needle setup, with full barrel open and LSN flush, gap is 1mm.

Regards

second_chance

before going any further, i hope you are not using castor ?

murcielago

Ans 1. There is no fixed criteria for this. It depends on ur fuel compistion n temp of surroundings.

Ans 2. LEaning out the LSN shall begin after ur HSN leanign is complete. If you can put ur finger on bac plate for more than 5 sec ur suffciently rich.

My personal way is HSN firstn then LSN n then in RL 53 if nothung seems to work mess with 3rd hidden needle. I keep the LSN slightly richer but it depends on indidual engine n flier.

3. My advice would be begin the whole procedure again (HSN den LSN n Den LSN is switched to slightly richer side)

4. Low to mid even if rich is ok. I prefer it linear.
5. Why did u mess with the hidden needle?? Ur engine temp was normal n u still havent finished ur tuning with other two.

Rest can be explained by second_chance. He guided me when i started with RL 53 engine. Anwar n laxman also have  experince with this particular engine.

And important thing is please put on the main blades, canopy while u do the tuning. I mean tuning shall be done with the dead weight on.

satishkbg

No, no castor. Using tornado 10%NM.

Well since I had taken the th-arm out to Loctite the hex-screw, I thought it was my chance to ensure the 3rd needle was in fact at recommended setting.
Will be putting on blades soon but i'm not an expert to control a punchout entirely, so will it make a huge diff if set with and without blades. I hope not, and should be able to compensate for loss of power if any by HSN alone?

murcielago

I havent seen people tuning their heli engines without the blades. Ur Wish if you want to stick with it. I dont see a point tuning without blades as putting on the blades changes the entire disc load n dynamics n hence, the engine behavior.


Complete ur HSN n LSN tuning for first few tanks while hovering. Then, go in idle up n just hover around for two tanks. No need for full punch outs. Keep monitoring the temp. if hot u can richen up the LSN by 1/16th n so on.

This will complete the break in procedure. In our field we dont tune the heli engine with full throttle. I have seen them doing this on a plane engine.

These are my two cents. I believe senior players like Second_chance, Anwar n Harveer can now help you out.

anwar

#33
Some pointers...

1.  As pointed out multiple times earlier, it only makes sense to do tuning (for anything other than idle) with the blades on.  The load profile has a significant impact on the engine.

2.  I have described the way I have been tuning earlier, and it has worked very well for me.  The "backplate touch for non-idle running", and "pinch and 3 second rule for idle" methods will get you very close to ideal tuning very quick.

http://www.rcindia.org/search2?search=touch+backplate  (read these threads).

3.  I don't remember ever going to full throttle on helis.  While testing initially without a governor, the first thing I did was to set the throttle curves so that the max point was around 80% for testing/tuning.

4.  If you are getting into 3D (or even just testing punch outs), your pitch curves and finger/stick management has an impact on how the engine responds.
Hangar : Please see my introduction.
RC India forum and me : About this forum.

satishkbg

Thanks anwar.

Yes I've been following the back-plate temp tests throughout the setup. Will do the pinch-test.
I'm now setting up Ely.q 50 (planning FBL) with the same engine & muffler.
I'm not into 3d at all - I'm in for the engineering and fine-tuning aspects of these machines.
I do fly when I got the time.

Thanks for the pointers.

murcielago

Hi satish,

Do post some pics of Ely q 50. I have neever seen one in person. Would be good to see the design etc.

Regards

Doc

satishkbg

As you can see i'm still putting it together.
It's an excellent design - 2 + 1 part, upper (main-gear, bearings, cyclic-servos and head completely come apart), lower (engine, clutch, main tank) and front (all other electronics). Most of the parts are raptor compatible. Things are on hold at Elq.Q a the moment though.

satishkbg

Main blades and tail blades pending.