polygoo

I am having some weird trouble with my caliber 30... I noticed that if I leave both throttle and pitch curves on linear (0,25,50,75,100) the helicopter has a nasty wobble at around half throttle to 3/4 throttle.

The engine sounded like it was screaming with those curves, and I was only hovering about 3 feet off the ground.

I checked my tracking and it seems fine, I cant seem to find out what the wobble is coming from.. so out of curiosity, I tried editing the throttle curve, and leaving the pitch curve regular.

I set my throttle curve to 0,12.5,25,50,75. At that throttle curve, the wobble goes complete away. and the engine sounds alot better and doesnt sound like its screaming.

The wobble came from what it seems like the main rotor, and then going to the tail and the tail was moving back and forth.

My question is this: is a wobble normal with too much RPM per Pitch? Does pitch stabalize the blades?

overall i'm really happy with the new setting as the engine acts and runs much better. I used to get a few boggs at the higher rpm.

I have the kyosho caliber 30, OS 32, futaba 7ch.

I dont really care about stunts, and I cant seem to find a decent tutorial on a good throttle/curve setting that overall is good (most websites take stunts into consideration)

P.S. my main rotor pitch is set at -2 to +~14 degrees

Thanks in advance!

BarracudaHockey

My Feedback: (11)

You want 10 at the top end 14 is way too much. I'd even reset the linkage so it tops out at 12, use that for your throttle hold pitch curve top end.

Your hover should be 5 or 6, if your hovering at half stick the point between there should be between whatever it takes to get 10 and 5.

Low end for training maybe -2. As you gain confidence bring the low end of normal curve to -4, then you can start on the idle up.

For throttle, 100 percent at the top, 50 percent at your or so at your hover point. The wobble is low head speed.

polygoo

hey, thanks! (again)

i'll try that but i thought it was because of too high of a head speed, rather then too low of a head speed that was causing the wobble... you really think that if I raise the throttle and drop the pitch that the wobble will go away?

If i'm at say 7 pitch with 40% throttle, how would 5 pitch at 50% throttle help?

Sorry to be a jerk and question you after you have so obviously tried to help, but i'm new to helis and I like to learn as much as i can so I understand whats happening and why this would fix it.

The engine was really screaming and it didnt sound good and i'm a bit afraid to raise it even more to be honest.. lol

Whats strange is that I have a small wobble at low throttle (before I get it off the ground) which seems normal, then as I raise the throttle it goes away, then comes back really bad at around 70%... its so bad that the engine starts to sputter.

Maybe i'm too rich in the carb settings? i'm burning thru fuel very fast and there is a crapload of smoke coming out of the pipe, maybe the vibrations are coming from being at high RPM and the engine getting too much fuel (causeing sputtering), (which then causes vibration)??


Thanks again!

BarracudaHockey

My Feedback: (11)

There's plenty that could be going on, and from the sound of it you have the high speed needle fairly rich. If you can hold your finger on the back plate of the engine immediately after landing you can go leaner. If its very hot, and you can't hold your finger there your too lean. If you can hold it there 5 seconds or so before it becomes uncomfortable your right about where you want.

Your idea of screaming and mine won't be the same necessarily but you want around 5 degrees and 50 percent throttle as a starting point for your hover and the stick at half. If your rich it wont hover at half and your head speed will be way low and it will wobble.

Ground shakes during spin up are normal as long as its not excessive, and its worse on hard surface than short cut grass.

I highly reccomend http://www.rcmmagazine.com and getting Rays Authoritive Helicopter Manual but keep asking and I'll keep answering.

Oh.........and try to track down someone that knows what they are doing. Even if you have to drive a couple hours to get it looked over and set right once, it will be WELL WORTH it in parts and agrivation saved.

http://www.modelaircraft.org and do a club search by zip code
or http://www.pilotlocator.net for heli specific info.

polygoo

ohhh, ok well that makes sense, I honestly think its related to my engine tuning. Thanks alot for all the info, i'm going on vacation tomorrow, so when I get back i'll be sure to try this out. I cant thank you enough!

I know alot about R/C but I am new to Helis in general, If this still doesnt workout then I think i'm going to seek someone to help hands on. so far everything has been going very well, and I actually already know how to fly because I learned on both a simulator, and another fixed pitch electric heli that I had for a while.

It sounds to me that the high speed is indeed too rich, which might actually be causing it to not be able to get up to RPM. The whole "screaming" thing is a bit subjective, when I say "screaming" I really just mean loud....

another thing i've tried was trimming down my training gear which did seem to help a bit. Maybe I should try taking them off to see if it goes away.

the other thing I need to do is check to make sure my flybar paddles are set excact, I think that could be causing it as well.

how do you guys check RPM on the headspeed? Is there a tool for that? I think that would help me pin down the problem alot easier.

Thanks again!

BarracudaHockey

My Feedback: (11)

http://www4.mailordercentral.com/hel...?number=804260

Optical Tach, someone sights through it and pushes the + or - bottons till the rotor appears stationary, then you just look at the readout. Really the only reliable way to set head speed short of a governor.

Training sticks will cause the shakes as well, they hit a resonance and vibrate.

Keep fooling with it, you'll get it. Enjoy your vacation.

credence

My Feedback: (2)

Seems a bit overkill maybe. I'm using a hobbico digital tachometer that works really great, and appears to be fairly accurate, as i'm getting the same headspeed many others are on my eco-8 with similar setups, it's also 1/3 the price of that optical one .

Just noting personal experience, thats all. Never hurts to have other options.

polygoo

Thanks a bunch guys, I really appreciate the help

I actually found another I hope this one is accurate enough...

http://www2.towerhobbies.com/cgi-bin...?&I=LXPT31&P=7

Later guys, and thanks again!

BarracudaHockey

My Feedback: (11)

There's a big difference taching a micro electric and a 30 nitro bird. You really don't want to put yourself in a position to be able to measure head speed at hover with a hand held prop tach.

credence

My Feedback: (2)

Eco-8 is about the size of a 30 nitro, and the tach works from a good distance away.