Got the shakes !!!

[rototiller]

Hi guys, I have a problem with my S50. The whole machine shakes pretty badly. Here is the history........

New assmebly, step 1, put motor in. The fan is .015 in out of round !! I did my best and got it down to .003. Not sure if i could get that last .002. Not sure if that would bother anything real bad or not.

Blades where out of track. Cleaned that up.

Tail shakes like crazy. Balance tail assembly.

Fighting new motor with gov. P.S. I dont think its a good idea to use a gov on a new motor.

Ran a normal thr/pit curves and the machine gets a little smoother.

Just tried a known good set of Radix and it cleaned up a little more. The other one's are MAH's.

The last thinig is i had a piece of lead on the tail to balance it. I just took it off and havnt tried it yet. Think i will notice anything?

Can you think of anything else? This is a brand new, never crashed or landed hard heli. The only thing left is try the stock dampers. i have on edge in dampers on there now.

DK

[WJackson]

Did you high point balance the fan/clutch assembly?

[rototiller]

That i did not do. The manual for the gov says dont worry about balancing after the mag. Its not enough to throw it off but, it was .015 out of round. Cant emaigne how bad the balance is. Plus i am sure the mag helpped it along. Are the rapter fans any straiter ???

it does feel pretty smooth when its running though. Took for ever to get the clutch to bell clearance good with out it crashing but, finally got it. Sounds good taking up the clutch but, all hell breaks lose when the blades get up to speed. Allmost a rythmic vibration.

The other heli we tested my blades on had some of the same rythum vibration but, soon settled into a pretty smooth hover.

Plus my tracking was all over the place. The Radix i tested track good right off the bat. I checked the dampers, not sure if i had them in right so i fliped them but, didnt seem to matter too much either way.

DK

[jpolidore]

Did you check the flybar lengths and make sure they were even?I found mine off by 1.5mm. I adjusted them, now I have no vibes at all.

[rototiller]

Yep, the head was balanced with flybar,then paddles and last with blades.

Really windy here soo wont beable to test. If i have to wait for this weekend then i will completely strip the heli this week and build it up like a kit. This is why I hate ARFS.

DK

[WJackson]

Balance the fan/clutch. Any shakes I have ever had have come from this. Of course check the flybar and the other but out of round is no biggie , out of balance , big biggie.

[WJackson]

Balance the fan/clutch. Any shakes I have ever had have come from this. Of course check the flybar and the other but out of round is no biggie , out of balance , big biggie.

[rototiller]

Ok, just got a test hop in. I was gonna tear into the fan but, noticed the timming ring was not set right. I straiten that up and double checked the paddles.

Its a bit better with the timming ring in place and known good blades. Plus i am getting the motor tuned better but, still some shake left and will dig into the fan to check balance.

Heres one for ya, in a hover tail in, the right side of the disk tracks but the left side is off. Any idea ??

DK

[WJackson]

usually if only half the disk tracks its a paddle issue.

[rototiller]

Well, balancing the clutch and fan took away 90% of the vibration !!! Yaaa !!!!! But.....There is still a rythmic vibration that hits the canopy every 3 or 4 seconds. Shake...fine...fine..fine...shake...fine...fine... fine. you get the idea. I really think its the out of round clutch. It looks pretty bad but, nothing i can do about that. If i put it on the lath to true it up it will be too small. Maybe a raptor clutch and fan ?? Uggg.

Motor is pretty much tuned now and is running smoother and has no problem pulling the 10 deg of pitch. I have to get a longer arm on the collective servo to get the rest of the pitch out of it. Its setup +10/-10 but it climb's harder inverted than upright. Needs just a touch more +.

The extra holes on the mix arms..........what would i get by moving to those? I am allready at 7 deg of cyclic. Would i get any more pitch range??

Thanks
DK

[ddierking]

Yea, I have noticed mine climbs harder inverted than upright.

[WJackson]

7 deg of cyclic should be perfect. What h/s are you running? If you turn the swash to mixing arm rods in two turns should punch out same both ways. See if uping h/s changes the resonation of vibe.

[rototiller]

Ok, I redialed the fan/clutch in. I have it balanced and with in .003 inch round. Pretty smooth right now. Just got back from two tanks. I ripped it up pretty good, for me anyway.

7 degs of cyclic is perfect. I had 1850 and 1950 in the gov. Ended up flying on the 1950 for most of the first tank and all of the second. Feels smooth and locked in at that hs. I have to tach it but, what ever it is, its good for me !!!

Started working on tic-tocs and i need a little more power. just runing the stock muffler with 15% cool power. I wanted to try and do them across the field but, not enough power for that so i only got a couple in. Plus i have some interaction on the swash. Roll left it will drop the nose and roll right it will drop the tail. Plus on the tic-tocs it wanted to twist the heli. I bumped up the gyro and that helped on the tail but, need to get in and retime the head.

Other than a little more fine tunning, I am pretty happy with the stinger. Just wish i didnt have to go thru all this to get it right.

Thanks a bunch for the help.
DK

[WJackson]

After the engines good to your standards, get a mp 2 or something, turn your idle 2 to 2150 and go to town ! :D

[rototiller]

I dont have the metal head. As far as I would go is 1950. Maybe 2000 but thats it.

Just picked up 2 gallons of cool power 30% and went with a 5 cell pack. That should keep me happy for a while.

I did get to fly my stinger back to back with a rex 600. Those two couldnt be more diffrent. The rex is just smooth. A bit slugish but smooth. No power!! My stinger is not the strongest bird but, it killed the stock 600 in power and agility. The stinger feels more like my built 450 than the 600 did.

DK

[WJackson]

I run 2150 on the stock head, if I ever have a failure I will let yall know.

[rototiller]

No kidding? What blades are you running ? Got any pics of your machine?

DK

[WJackson]

600 gohbee blades, ill post some in gallery. like I say, "Fly it till it drops!" :lol:

[rototiller]

Just got back. What a diffrents the 30% made. Runs way better and more power. Plus the 6v at the servos allows me to do tic-tocs at only 1800 !!! I mean, they look like tic-tocs, not like my earlier attempts. I tried 1950 for a little and this thing will keep up to my 450 in roll rate !! Just awsome.

DK

[rototiller]

Ok, I am flying more aggrissive than i ever have before. This thing rips now. But i do have one preblem left.

When i give full neg pitch it acts like i gave right aileron too. Its driving me nuts. Its keeping me from doing some of the harder stuff, backward inverted, tic-tocs aross the field (I would call them wipers ?) anything that needs full neg pitch. Pos seems fine, its just neg.

Any ideas ?????

DK

[WJackson]

did you use any trim to trim the heli?

[rototiller]

Ya why?

It hovers the same upright and inverted. Just when i start to pile the power on it tweaks when inverted. Maybe the head is flexing?

DK

[WJackson]

I notice that a little on one of my helis, but its not "that" noticeable. Atleast I think its the same thing your talkin about.

[rototiller]

I built a mix to add a little left when adding neg pitch past hover. Took 10% to get it cleaned up and now it tracks strait when i stretch out the tic tocs. Maybe now i can start working on my inverted backwards stuff.

Still have this strange shake. Its there then its not. Somtimes the blades will track on both sides and some times it wont. Not really sure if its still the fan/clutch causing it or if its somthing else. I have double checked everything and it all seems to be good. Really wish i could get this sorted out.

DK

[rototiller]

FINALLY FOUND IT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I took the on edge dampers out and put the stock back on. YAAAAA !!! Smooth, no vibes and even more agile and stronger than before.

Thank god I found it. It was driving me nuts !! LOL.

DK