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os 32 tuning help please!

skewed

Heliman

eugene, oregon - usa

okay turning to you guys again!

i am a nitro newbie so i dont really have a grasp of normal.

i finally was able to crank up my new to me caliber 30 with os32 today. i did get it started but it is spewing fuel out the pipe and not creating much smoke. i am able to get it to idle okay. back plate never gets hot enough for me to have to remove my finger. mostly just warm. also, it seems like it is leaking a bit from the pipe/engine coupling (i will tighten it up).

btw- using sig heli 15% with 22% synth oil, when i rev it up a bit it does start producing some smoke not a lot though

-is it normal for it to spew a lot of fuel out the pipe?
-is it normal not to have much smoke (due to the synth oil)?

after i get it started the starter shaft never slows down. removing it is a bit daunting as it usually gets toss about when i yank it out. is that normal?

thanks for helping a clueless guy out. cheers,
ryan

01-23-2009 Over year old.
chris6414

Senior Heliman

Sneads Ferry, NC USA

Century came out with a wand with a one way bearing that eliminates the difficult removal after start up. I have the old fixed type and you'll find you can tell when it is running and easily remove the wand once you get used to it. Your LS needle may be a little rich but if it is running, then leave it for now till you hover check it. I have my HS needle(one you can get to with your finger) turned 1 3/4 turn out from closed. This is the 1/4 richer than full throttle factory setting and is in the ball park for winter flying here in Pa. If once running, she transitions smoothly to hover rpm(Half stick in normal mode) then your LS may be close. Keep in mind it will sound rich and slobber a bit until it is warmed up. Usually only needs a minute or so of running. If at 40-50% throttle, with about 5 degrees of pitch, she is 4 stroking, then you may adjust your LS needle(inside throttle arm) in a few degrees (1/8 of a turn or less) to let that half stick running smooth out. I keep mine a little on the richer side at hover. I run 15% Nitro, 18% oil plane fuel in mine and she doesn't smoke like the professionals you see running 30% Nitro with 22% or more oil but you should see a steady stream coming out of the exhaust once the engine is up to operating temp.

On my Hawk with a .32, I don't exceed 9 degrees of pitch at full throttle, in fact I run about 8-8.5 and 5-5.5 at hover. If your pitch curve is not right you will get erroneous hover tuning indication on your motor.

Century Hawk Sport, OS .32, Futaba 7C, GY-601 9251
Predator Gasser SE G-23 JR gyro/servos

01-23-2009 Over year old.
skewed

Heliman

eugene, oregon - usa

Keep in mind it will sound rich and slobber a bit until it is warmed up. Usually only needs a minute or so of running. If at 40-50% throttle, with about 5 degrees of pitch, she is 4 stroking...
thanks chris! that makes sense, good explanation. when sitting on the ground idling '4 stroking' is normal? the engine doesnt really warm up until it has some time at high revs?

i will get my training gear on it and start hover tuning asap.

right now i have the blade off and did get it to smooth out at higher revs and produce some smoke and it did slow up on the 'slobbering'. i guess it transitioned to clean 2 stroking?

all new to me! people talk about listening and hearing a good smooth engine, i just dont have any experience to know what all is normal and good. i am slowly figuring things out step by step.

cheers,
ryan

01-23-2009 Over year old.
chris6414

Senior Heliman

Sneads Ferry, NC USA

First, don't run your motor without the blades on. You can overspeed the motor and your head components and you don't want that. Second, slobbering rich at idle after it warms up is not really what you want. Lean out the LS needle a bit at a time until you have a good idle and smooth transition up to hover speed. I transition slowly(Scale) for clutch life.

Yes, it takes some running at higher speeds to warm the motor up.

I had to relearn Nitro having flown planes for years. OS .32 LS needle controls the fuel mixture all the way up to about 75% Throttle. The HS is for higher settings to max. My sweet spot has me at a slightly rich idle with good hover/smoke/speed and temp. In fact after a good long two minute hover, I wanted to see how she would idle and she will idle all day. If after a hover check she will idle but will start to load up after about 10-20 seconds, then the LS is still a little rich. Idealy, you want to be able to hover(1 -2 minutes) , idle for a long period(1 minute or more)without loading up and then transition back to a hover. Once you can do this your LS needle is pretty much set. Also, make sure you HS needle is set at least 1 1/2 turns out(factory setting)(If I punch from idle to hover speed she will spit a bit until she gets up to speed which is fine with me. Richer is always better than a little lean.

Century Hawk Sport, OS .32, Futaba 7C, GY-601 9251
Predator Gasser SE G-23 JR gyro/servos

01-23-2009 Over year old.
skewed

Heliman

eugene, oregon - usa

chris-

thanks for more good info. i will install the blades and training gear and give it a shot. i was testing it out on the bench and was leary of the blades being on. time to take her outside and see if i can go some hover tuning. i think i have a decent grasp of how to proceed. it jsut a whole new thing to me.

cheers,
ryan

01-23-2009 Over year old.
skewed

Heliman

eugene, oregon - usa

more questions

i installed the blades and have spun it up now. with my tx set up fairly close to whats recommended on the raptortech site:

t/c 0-50-60-70-100
p/c 0-2-5-7-9

when i approach mid stick i am getting a nice amount of smoke but i start getting a disconcerting wobble (maybe at 50-55% throttle and 3 or so degrees pitch). the heli starts to rock left and right on the skids. i eased back on the throttle when this started up of course.

are my blades that out of tracking or the engine too rich and rough or too high of a head speed or normal? the engine seemed to spin up fairly evenly and smooth (in my very green opinion).

thanks guys!
ryan

02-02-2009 Over year old.
dkshema

rrMaster

Cedar Rapids, IA

The Caliber 30 (and many other helis) will wobble badly if your head speed is too low.

The Caliber wants a head speed of at least 1800 RPM, and loves 2000 to 2100 RPM. If you're in the less than 1800 RPM range, the heli will wobble in the air as if it's going to explode.

You will also see a "wobble" as you spool up the head until the centrifugal force present forces the two blades to their correct flying position. If the one of the blades has too much lead or lag in it when you start up the head, the entire head is unbalanced and the heli will shake momentarily as you spool it up.

The blade bolts need to be tight enough so that when you straighten them out, then turn the heli on its side, the blades stay in position until you give the heli a bit of a shake.

Too loose, or too tight on the blade grips can cause weird problems.

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The smoke, the oil coming from you motor is an indication that you are way too rich on the needles. The fact that your heli is wobbling also tells me that you're too rich and as as result, the head speed is too low.

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The OS 32 carb is not an easy carb to tune, as the low speed needle (the one that's recessed into the carburetor barrel on the motor's right hand side) affects the main needle setting up to 75% - 80% full throttle setting.

If you get the low-speed needle too lean, you'll find that you have a great idle, and a great transition up till about 80% throttle. As you open the throttle further, suddenly, the motor seems to be too rich. You adjust the main needle to correct THAT, and suddenly, the motor begins to sag in flight above 80% throttle, quits lean, and usually results in a scored piston, ring, and cylinder.

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Mechanically on your Caliber 30, full throttle should open the throttle barrel all the way, without stalling the servo.

Full LOW throttle and FULL LOW TRIM should close the barrel completely, without stalling the servo.

With these two settings, you should see the following behavior:

Full low throttle, full low trim, the motor will not start. You can use this to kill the motor from the TX any time you need to.

Full low throttle, mid-throttle trim setting, the motor will start, it will idle well, and the clutch will not be engaged.

Full low throttle, full throttle trim setting, the clutch will engage and the head will begin to turn.

-----

First step is to set the two needles at the factory recommended setting. With the low speed needle and the Caliber 30 (and most other helis) you'll need to drop the motor so you can look down the carburetor barrel. The low speed needle is adjusted using a flat-tip jeweler's screwdriver.

Once you get the two needles set at the recommended factory setting, start the motor, and USE YOUR THROTTLE TRIM TAB to set the idle speed. Resist the temptation to adjust the low speed needle to get a good, steady idle at this point. Doing so will guarantee a very lean top end and a fried motor.

Once you have the motor running and are keeping it alive with the throttle trim setting, increase throttle to the point where you Caliber is just about to lift off. It will be very light on its skids. The motor should pick up RPM without spitting, coughing, choking, gurgling, and it should not instantly die.

The transition from idle to the near-lift off point should be steady and even. If the motor spits out a lot of fuel, blubbers, or speeds up erratically, your low speed needle is too rich, and needs to be leaned out a bit.

If, as you increase the throttle, the motor either just quits (without a lot of fuel present) or hesitates, then picks up, the idle is too lean.

-----

Eventually, you will check the low-speed needle setting by letting the motor sit at idle for about 30 seconds, then you will simply pinch off the fuel line and watch what the motor does. It should continue to run for about 3 - 5 seconds before picking up speed and stopping. If it runs much longer than that, the idle is too rich.

If, on the other hand, the motor quits almost instantly, or stops before the first three seconds, the idle is too lean, and must be richened up a hair.

This is the "pinch test" you may run across as you read more and talk to more pilots.

-----

Back to the initial needle settings...you've gotten the low speed needle adjusted now so that from idle to the near lift-off point, the transition is smooth with no blubbering, coughing, spitting, or hesitation.

Also, at the near-lift off point, the motor should be running fairly well, and should be developing sufficient power to get you into a hover without problems.

Once you have the low-end set, the next step is to fly with the throttle wide open and note how the motor sounds, and how it is performing. You adjust the high speed needle (the big one that you use your fingers for adjusting) to get the top end set correctly.

I find that if you simply nail the throttle wide-open and let the heli climb, you can tell a lot about how well the top end needle is set. You want the heli to climb well, the motor to run strong and not bog down or begin to sag. Gradually (a couple of clicks at a time) lean out the main needle so that you get power, a good, steady climb, and the motor doesn't begin to sag off as you keep the load on it. That is an indication that the top end is too lean. Throttle back quickly, land richen up a few clicks.

It's a trial and error process. As you get both needles set initially, go back and fine tune them, as they do interact with each other.

Stay a bit on the rich side at full throttle to keep your motor happy.

-----

With an OS 32, the Caliber will want to see about +/- 9 degrees of collective pitch, maximum. You don't want to exceed about 6 degrees of cyclic pitch on elevator and aileron.

I generally have my Caliber 30's set up for -3 / +6 / +9 degrees (three point curve to start with, adjust the other points to suit your motor, fuel, and local conditions) for Normal flight mode.

My Idle up 1 setting is usually something on the order of -5 / +6 / +9, and my Idle up 2 setting is usually -9 / 0 / +9.

Throttle curves for Normal mode have been 0 to 100 linear, something on the order of 60 / 50 / 100 in Idle up 1 (fine tune later as you are flying the heli), and 100 / 70 /100 in idle up 2.

With an OS 37 and decent muffler the +/-9 degrees pitch settings can usually increase to +/- 11 degrees.

Retain the 6 degrees of aileron and elevator cyclic.

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At hover, if you find the head speed too low and the heli wanting to wobble (even in forward flight) you'll want to increase the throttle curve setting, and reduce the pitch curve value to get higher head RPM.

I find that at hover, I sometimes need to bump up the HOVER THROTTLE setting, and tweak the HOVER PITCH settings on my TX to get a decent head speed without messing up the overall pitch and throttle curves.

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The third post here:

http://www.runryder.com/helicopter/t206926p1/

describes in great detail the initial setup of your Caliber 30 mechanics. I wrote it several years ago and it's helped a lot of people since then get their Calibers up and running.

The ninth post here

http://runryder.com/helicopter/t272559p1/

again walks you through the OS 32 tuning.

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About your starter. You MUST use a starter wand that has a one-way clutch installed in it, or as you've seen, it's very difficult to remove the start shaft after the motor is running. If you continue to use a starter wand without a one-way clutch in it, you'll also eventually round out the hex tip of the start shaft.

This start shaft works great, has the one-way clutch, and has lasted me for several years now:

http://www.heliproz.com/prodinfo.asp?number=805390

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

02-03-2009 Over year old.
skewed

Heliman

eugene, oregon - usa

dave-

once again thanks for the excellent post! lots of great tips.

mechanically, i think i have everything set up per your other posts tips.

i will try tweeking my throttle and pitch curve to get a higher head speed and try and get rid of the wobble.

my biggest problem is--- i still cant fly very well. i am doing well on the sim but actual air time is not too impressive. i will work on getting rid of the wobble and getting the low speed needle trimmed so i can hover it until i feel comfortable with testing out the high speed needle by going to full throttle.

i hovered my beam for a couple of minutes yesterday before getting nervous and dumping the stick before running into some trees. almost have it back together though.

without one on one in person help i am forced to take all of this at a slow pace. i am still having a ball with it and i will be persistent!

i will keep you posted- cheers,
ryan

02-03-2009 Over year old.
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os 32 tuning help please!

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