Blade balanace?

[chaos]

think my pitch is off now after crash

That's usually the case.

thinking something may be stripped

What model heli do you have? I'd like to see if I can find a manual for it on the web and maybe understand the situation better.

A bent feather spindle makes me think the blades broke.. and maybe the flybar got bent... and maybe the drive shaft got bent.

Anyway, if you put new blades on it then they might need to be balanced, and when you get it together you'll need to check the blade pitch and then run it and check the tracking.

[shanee86]

Yes the crash I think I said this above not sure. Bent the feathering shaft broke blade and almost everything on tail. But I fixed it now and been test flying it and it was shaking alot but me and step dad checked the pitch and one was way more then other so we fixed and no more shaking. Also I have the hawk pro 30 size. I also have other electric ones but that is one in this thread. But anyway yea tracking is a little confusing to me. What exactly do you do if it is off like change the length on pushrods or what? I have a cp and it tells about that in the book but not sure?

[chaos]

But anyway yea tracking is a little confusing to me.

It means getting both blades to follow the same path. If one of the blades has a little more/less pitch than the other then it will fly a little higher/lower than the other. This makes it wobble a bit.

To fix that you need to be able to identify the blades, so usually a piece of tracking tape is added to one blade. Or to maintain balance you could put a bit of black tape on one blade and red tape on the other. Anyway the blades need to look different.

Then, you bring the blades up to speed, preferably at zero pitch, but anyway you want to keep the heli on the ground so that you don't have to bother with flying it. You just want the blades to be spinning. Then you look at the blade edge-on. You will see both blades overlap in the same path if the tracking is correct. If the tracking is off, the blade with the red tape, for example, will be a little higher or lower than the other. It's all a blurr with the blades spinning, but you'll be able to tell which blade is higher or lower.

Then decide which one you want to adjust, and adjust the link that goes from the blade to the mixer lever. Make it one turn longer or shorter. Then wind up the blades again and see how you did. You might have to go through this several times to get it right.

[shanee86]

Thanks just a updated since I crashed on christmas my motor has been out of tune. So I have been trying to test fly it and tune it. Tuning is a pain lol. We had it all tuned out before crash so making me wonder. I am now using my new fuel it is 25% nitro instead of 30% and we put in a new glow plug because I thought it might be that after reading on here. But I am unsure my dad know more about tuning these things then I do I am learning I tryed to tune it out there today but still not working. It is dying at low stick and when you peg it and losing power in the air. So I richened the low end and high end some more. We had high end rich already but not much smoke coming out. So I did both not much but some. I will have to have dad help probably. He is thinking it is wierd because we had it tuned almost perfect before crash and to rich he says lol but that was because it was running lean because of a screwed up fuel filter we found out. So yesterday night we took the tank apart and check the filter inside tank and nothing wrong. So we added another tube so we could fill it better. But it still running bad. Also every time I start it now I have to give it like full throttle I am scared to do that lol so I gave it about half or lower today and took forever but got it to start. But then it kept dieing any ideas? My dad will be home and maybe we will just take the motor out of heli and test it or he will like we did before if it comes to that. But yea tuning sucks lol because I am not that good at it yet.

[chaos]

every time I start it now I have to give it like full throttle

Yikes!!! I wouldn't do that.

Suggestion. Take the main blades off till you get the engine under better control and put just a little fuel in it. If you're using a header tank just put 1/8 in it... just enough to cover the clunk with a little to spare. If the thing goes nuts it can't take off without any blades and it won't run long without much fuel.

Check the throttle system. Unhook the link at the throttle servo and make sure the throttle arm on the carburetor isn't slipping. It's possible that it loostened up and might be set wrong. When you push/pull the link to the throttle arm by hand it should hit a solid limit at the ends - full open/closed - and not slip. When the radio feeds 50% throttle the carb the carb should be half open and the pushrod should meet the carb arm and the servo arm at 90 degrees. Make sure full throttle stick on the TX actually moves the carb to full open, and full close when you put the TX to cutoff. With the radio on, make sure the throttle servo is holding... try to turn it and it should resist. Possibly a gear is stripped in it.

Unplug the fuel line from the engine and unplug the line from the muffler and blow into the line that went to the muffler and make sure fuel comes out at the end that goes to the engine.

Set up the idle mixture and main needle valve according to the manual for the engine. You should get some life out of the engine at no more than 10% throttle. Once it runs do the "pinch test" to get the idle mixture set then try to hover it. Adjust the main needle as needed to get a good run in hover. If you had to adjust the main needle for the hover then recheck the idle mixture (do the pinch test again).

[shanee86]

Yea I know I been trying just half throttle scary my dad is like you get scared to easy if your going to be like that then gas helis are not for you lol. But anyway I thought I would let you all know why it was doing this. Well I and my dad pulled the motor of it and then looked it over because my dad said it seems to be sucking air. Well it was the head was coming lose and after we had it off I noticed that my finger made the head move lol so we will fix that and then test run the motor with a prop and tune it out then put back it. Then I should be all good to go.

Oh also one more thing I forgot about and thought you might like to hear. The other day my dad came home after I tryed tuning it and it was flooded he said, and I was starting it at alot less then half throttle plus he turned the low in out or richened it out alot. Then he started it up at full throttle and then he pulled the stick down and gave it to me to try and test fly it. Well that is when blades started to go faster and faster and faster and I turned it all the way down and the idle. But it just kept going and was probably going full throttle so I got scared bad lol. But since there was not pitch on blades it didn't take off looked for a sec like it almost did hopped a bit. But thank god it didn't go up. Then it died finally after a awhile. So yea my first gas heli has been scary lol. Then we looked at the bottem of heli and there was alot of fuel on the ground. So my dad said it was probably flooded so it was burning the fuel out. Well as I said it had leaked fuel so it was probably because head was lose when we got it out scary lol. But yea the head probably got lose when it was vibrating so bad because pitch of bladed were off or in my crash.

[chaos]

Hey shanee86, thanks for the update. These things can get scary.

The guy at my LHS started up a 90 (his) - in the shop - but he had the servo reversed and the throttle was wide open instead of idle like he thought. That thing jerked to life and knocked the TX off the counter and broke it, and he was busy with both hands trying to hang onto the heli. Fortunately he's a fairly strong fellow and was able to hold the blades still, but he couldn't do anything else. Another fellow had to reach over and pull the fuel line. During the fairly brief time it was running it was milling away at the clutch liner and filled up the hobby shop with blue smoke. It was kinda funny.

Anyway, I made it a rule to deal with a newly built, or rebuilt heli in a special way. I leave the main blades off and only put a little fuel in it. Call me chicken, but I like keeping my feathers on.

said it was probably flooded so it was burning the fuel out

Maybe so. But don't trust any links or servos after a crash till you check them. The bolt that holds the throttle arm onto the carburetor can get loose and then you don't have control over the throttle. I power up the radio and give the servos a little twist to make shure they're holding and the gears aren't stripped. And to check the throttle arm you can pull the link loose from the throttle servo and push/pull it till it stops and make sure there is no slipping there.

[shanee86]

Yea I checked the linkage before going back out kind of or look over didn't take them off or anything. I almost always look over my heli after ever flight to make sure something isn't broke but a end on a pushrod is hard to see if it is cracked we had that happen once but figured it out and didn't crash thank god. But yea I am hoping to get it back up by next week.