xcell 60 questions

[aerocal]

Ok Ive flown this xcell60 a dozen or so times.Metal frame ,OS FS61 ,stock head with the long shaft,constant drive tail,10t pinion/90t main,401gyro w/9254,extended tailboom+yes TT,Helimax690mm + CY95 blades,LiPo 2-1reg AR7000,thats the basic stuff.Im not sure of the exact tail gearing.

What kind of headspeed should I expect to be acceptable? I had real trouble getting throttle low enough to keep it from running right up over 1500-1700 and ended up with normal Tcurve around 0-13.5-20-38-56 trying to keep it around 1500 HS.I didnt really get to to any real hard climbouts past 3/4 stick or so and it might need more at the top.The reason I wonder is much over 1700-1800 somewhere around there it starts making like a ratle sound.More like a clacking or clicking.Kinda spooked me a little so I slowed it and made sure it didnt get to that rpm.Bearings are all new.

With this low of a throttle curve would I maybe be thinking of going lower than my current 9-1 gearing? 1500 HS should be 13600 engine rpm if Im thinking right.Seems about right.Its fine for sporting around now but I have a scale body and it might want to lift a little more sometime.

Im wondering if the noise is an engine bearing or possibly detonation.When I put this thing together there was no gasket/shim in the head.Im running 20% swampfuel (CPhalf 30heli,half 10air).It sat for awhile but the bearings seemed smooth and clean.There were some funny marks on the top of the piston.I need to look into that again now its had a few flights.

Should I possibly be able to run 700 or 710 mains? I measured clearance and I have 26mm now with the 690s and CY95 tail blades.I have a set of 700s that would be good spares.

It flew really well until the tail servo went out.Dumb me after
everything and making it fly nice forgot to put a reg on it and burned it up at 6volt I guess.It twitched once or twice and went to full left and locked there.Lucky I was 15ft up and almost back to hover from a fast FF hit auto and got it down on the skids.Only damage one of my CY tail blades when the vertical got pushed over and the blade hit it.Oh yeah crown gear.one tooth .

Now its about ready to go unless I put a shim in the head and mellow it out some more.Suggestions or comments appreciated.

[Peter]

Sorta sounds like its WAY too lean ; is it a 2 or 3 needle carb on the motor ??? do the new bearings include the motor bearings?

You should have no hassles hovering at 1500 and running to 1750+ at full noise..

710's might be a tad much for a 61, depends of your flying style too; I have 700's on one of mine with an OS70, it's pretty good, def not a powerhouse , but easy to fly....

[aerocal]

Thanks Peter.Defineitly not too lean and Im not having any problems really.You referred to running at "full noise" and this is kind of what I encountered.Around 1700 a bunch of noise starts and it sounds like it is from the head.Not that its bad or anything it just sounds like all of a sudden you can hear everything working in the head.Is this just a specific sound from this model heli? I was just trying to reassure myself it wasnt the sound right before pop,ding ding,flappity flappity flappity,WHAM.It is actually a cool sound sort of like listening to a watch with a stethoscope.If it is normal then I kind of like it and I think I want more. Some may say this old xcell is a dinosaur but man I love how it flys.
P.S. I didnt change engine bearings when I disassembled for inspection. They were clean and tight and seemed close to new like the rest of the engine.
Scott.

[terb0]

Hi Scott. That heli will hover just fine even down into the 1400 range depending what dampers and shims you have in it. It will fly fine at even 1800-1850 range. Do you have your flybar arms drooped? these will hit the bottom of the blade grips if they are not drooped and or if you have to much cyclic. To check for clearance put the cyclic stick into the corner and hold it there while you rotate the head around and watch the flybar arms for clearance to the bottom of the grips. Also look for vibrations as you get into the higher head speeds. If you dont have the fan dialed in close enough it will cause a pretty good rattle at higher HS's Do yo have a uniball clutch or the old style? Bad vibes will eventually crack the frames thru around the upper clutch bearing block. The fan needs the be dialed in at less then .001 if you want a super smooth engine run
Hope this helps Tom

[aerocal]

Hey thanks Tom.Sorry I didnt get back to this right away.Yes that does help.I think it was maybe more like .002-.003 when I checked it.It had slipped my mind so Ill pull it back out and get it closer if I can.Old style clutch.Yes I did get the flybar arms drooped and the head all works good.I spent alot of time and wondered if I was screwing up or not.I changed alot of the setup quite a bit.It had +6/-1 maybe 2 of pitch.8 degrees total and maybe could have tweaked a little more in.The head is good now 18 degrees total however I want to use it.I plan a scale body on it so I might bias the setup towards positive for scale.I put everything at zero on center for now.+9/-9
Ill have to sit down one of these nights and put it together again.Its been a fun learning experience so far.