Test flight, but something is still not right. Pitch?

[HeliMix]

Well, I got my servos rebuilt after my last crash as well as replaced the main blades and feathering shaft. I was able to spin it up last night and it flies, but something is still off. If I had to guess, I would guess it is the pitch since I worked on the servos? I am not sure if I got the front servo horn back in the exact location is was to start with. So, now I need to learn about setting up and checking my pitch. I will be looking for a good video on it but if any one has one already bookmarked and wants to share it, feel free.

Below is a short video of my flight. With the heli seeming to move around a bit on its own, I was a little scared to keep trying to hover in the tight area of my backyard so I went back next doors. Not sure if you can tell by watching, but the heli will drift to the side a little on its own without stick inputs. I am not sure if a tiny breeze was catching it and making it move or what. Again, my only idea at this time is the pitch.

My flybar was slightly bent in the earlier crash but I do not think it is that bad. With one hand I was able to straighten it out and it looks true.

If anyone sees something happening in the video that my newbie eyes do not, please feel free to chime in. If I can think of any other issues I will add them. At work right now so my mind is sort of on other things, but I wanted to get this started so maybe during lunch I can do some studying on adjusting my pitch.

If this makes any sense, I feel like I am chasing the heli? Once I get in into a hover, it moves up or down or to the side without stick input. What is causing this is where I am lost. Not sure what to address now.


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[mituw16]

gotta ask.....
the servos aren't stripped are they?
(i know its probably the first thing you checked, but often when i am having problems, i find the problem is something obvious)

if they arent stripped, the swash, wash out block, and flybar cage are all level arent they?

do the blades both track okay?

[HeliMix]

Servos were stripped. The front three have been rebuilt and are working smoothly.

Blades are balanced and tracking well. Flybar cage I think is level. I know the paddles are. My guess is swash is off or the servo that controls the pitch of the blades is off.

[mituw16]

just a thought, before i upgraded my servos i rebuilt the stock ones several times, and one of the times i rebuilt them, the elevator servo was still not working properly even though the gears were okay. check all the servos under load..... if its not that

level the swash and wash out block (if you havent already, watch sokal's video on swash setup, it explains it very well)

[fdrotormedic]

Hate to say it, but the training gear does make it a little more difficult to get the heli trimmed out. Consider changing the throttle curve and pitch curve to be a little less aggressive. This will reduce the headspeed and help in the "learning curve". Do not do anything other than hover while you have the throttle curve reduced. You will need to set it back for 3D flying. I started my throttle curve at 25-40-60-75 which will reduce the headspeed. You can change the pitch curve as well, just be sure to have about 10degrees of pitch at 3/4 stick.

[HeliMix]

This was not the first flight. The point here is, the heli flew fine before. I have rebuilt the servos and now it does not handle the same as it did before. That is the issue to be corrected right now. I am trying to figure out what changed and what needs to be tweaked.

Thanks for the tips mituw16. I will check out Sokal's vids again. Watched them all early on, but sometimes things do not make sense until you get further down the road. ;)

Any additional feedback is greatly appreciated.

[sparx-]

Anytime you mess with servos, you need to go thru the head setup again. You cannot just pull a servo, install new gears, reinstall servo and fly. Odds are the center point is not the same. You will not always put the exact same servo back in the exact same spot.

SPaRX

[HeliMix]

But one may try hard to do so without changing anything. LOL I actually marked things and took photos before I began, with the exception of the front servo. That one I did not document.

Thanks everyone. Lunch will be here soon and I will watch Sokal's vid on head setup again while eating. But if any one still has two cents to throw in, hit the reply button.

[mituw16]

as lock would always say "Don't forget to re-bind!"

[Ti RX-8]

Thanks everyone. Lunch will be here soon and I will watch Sokal's vid on head setup again while eating. But if any one still has two cents to throw in, hit the reply button.

LOL. 9-5 is for posting to this forum, but you have to wait `til lunch to watch the vids!

[LockMD]

as lock would always say "Don't forget to re-bind!"



:thumbup:

[HeliMix]

Well, I check posts and make posts in between saving files at work etc. Then lunch is mine at my desk with Wendy's, HF and YouTube. Then after work, head home, pet the dogs, feed the dogs, get something to drink, and then back on HF. Yes, I have an illness. :lol:

[HeliMix]

After I got home, I looked at things on my heli. It did look like the swash was not level at half stick. So I popped the rods off and leveled it out real quick. THen went next door and it flew much better.

Not sure how, but I think my flybar paddle control frame is no longer level. None of that was taken off during any of the repiars either. I guess working on the servos was enough to throw all of that off too?

It is supposed to rain starting tomorrow through the weekend here. Guess I will tear the head apart and check it all out.

Two questions. What would a heli do (how would it fly, react etc) if...
1) ...the main rotor blade(s) pitch is off, like a pos 4 or so?

2) ...the main shaft was bent so slightly it could not really been seen by eye?

[Bone]

I am just a newbie, but with my b400, I have found that one blade having a higher/lower pitch can cause a real bad vibration and will mess up your tracking. I had one that after a crash was off 3/4 of a degree. The main shaft will cause vibration, which makes it harder to control and confuses the gyro, compounding the problem. Not to mention putting extra wear on bearings.

[HeliMix]

Well, I guess that is good news, because vibration is not my problem. And the blades track great. It is like there is play in something and one minute it handles fine, then it gets this push, kick, what ever, and moves a tad left, right, up, or down. Cannot pin point it yet. Again, really need to tear the head down I guess this weekend and make sure the main shaft on up is all in order. Grrrr... Cannot wait till I know this stuff and do not feel lost. :confused: :lol:

[mituw16]

so are you saying its flys like there is some slop in the controls? did you try lubing and replacing the o-rings.....also how many shims do you have on each side?

have you tried putting in some exponential? I fly 3D and still have 20% expo (i know extreme 3D pilots say no, but i dont want to crash from over controlling)

if you still can't pinpoint it, i guess the only thing that i can think of is to really take the time to take apart the head and re-set the swash, wash out block, and flybar cage.

also make sure the blades pitch are tracking and the pitch alignment is good

[SeanOC]

I hate to ask but why and when are you supposed to rebind??? I feel like thats a dumb question.

[sparx-]

Anytime you mess with your servos you should rebind.

SPaRX

[SeaComms]

The bind process resets the servo centre point, or default point in the event of a link failure, so if you ever reset the servo trims either mechanical or electronic, once set you should rebind so the reciever 'knows' this new default centre position. In the hopefully never event that you do get a link loss situation you want it to be flying as close to level as possible I would guess. Just a shame the default for throttle is always off, would be nice to be able to set a default of a nice hover speed.....

[HeliMix]

Ahhhhh I thought you only had to re-bind if you made a new profile on your Tx. :DOH

Ok, so that is what I need to do when I get home, first thing. Re-bind.

Yes, it flies like it has some slop in it. I have o-rings and the default four shims on each side of my head. I was looking at it all last night and the head does seem to have some play in it in a few places. The head itself, the flybar square thingy (I cannot remember the correct name right this minute), and even around the swash. But to tell you the truth, I did not look at my head this way when it was new (should of and should have taken pictures and vids of it before flying so I knew what it should be like).

I can see now though where a new head, something stronger such as the aluminum AM heads would be good. I may have to do some part upgrades before I am really flying. I think that tighter control would help.

What ever the problem is, I am sure it can be resolved for after I did some tweaks to some of my swash plate control arms last night, it flew better. Guess I will re-bind, and then work on the head if that does not clear things up.

Stupid newbie! :oops:

[SeanOC]

Damn so since I adjusted my head the other day I will have to re-adjust everything after I rebind?

[LockMD]

re-bind re-bind, I may have said it once or three times :)

yeah ANY changes you make that affects the servos you need to re-bind

[HeliMix]

re-bind re-bind, I may have said it once or three times :)

yeah ANY changes you make that affects the servos you need to re-bind

I'm sorry, did you say re-bind? :shock:

[SeaComms]

Damn so since I adjusted my head the other day I will have to re-adjust everything after I rebind?

No you shouldnt, rebinding wont change any settings, it more of a save point where it resets the defaults to the way you NOW have them set, rather than the way they were set. The rebind process is the last thing you do as a result of making changes to settings, it will never require changes to be made because of rebinding.

[HeliMix]

Well, am I missing something? I looked at my DX6i manual with regard to binding, and they say plug the bind plug into the charge plug receptacle. I do not have a switch like that (that it also says is not included). I guess I need to go to the LHS and get the switch?

I am searching up here but most hits are just mentinoning binding, not how to do it.