Co-Comanche
 

Bought some REALLYcheap Lama blades for my Co-Comanche off Ebay. I got them in and they are almost twice the thickness of the OEM blades. Pretty hard I must say and hard to break also. Problem is now the chopper will not fly right. Terrible blade slap and it drifts all over the place. Note: before the blade change the heli would hover almost perfectly still with no control input, I had it trimed nicely. I can't adjust it through the controller trim and have also releveled my swash plate but still not the way it should be. problem now is i have great left right response and great backward speed but when Ipush the cyclic forward, the nose just kinda dips down the chopper lunges forward about 3 feet then stops on it's own, even with me holding the cyclic full forward??? Any Ideas? All started with the new blades but only thing I can think of is that my swash plate is still a little out. Also: when i do lung forward, it wants to fly forward and left? If i push the cyclic straight forward with no aileron input it tends to want to roll to the left after it gets moving forward, that is until it stops.

Stock Co-Comanche
New, thicker, heavier blades "Cheapies"
Shortened Flybar
800Mah Battery
2.4GHZ setup

Thanks

RE: Co-Comanche
 

Sounds like the cheap blades are to blame.

First, check the blades for balance. If out of balance add weight with tape. I use clear shipping tape.

Next, check that the blades are tracking correctly. They should look like one flat blade when rotating. If they look like they are going up and down at the tips, bend untill they track.

Next, spend the extra $$ on a set of Xtreme blades. Very strong and well made, although I have had a set that didn't track. Easy fix, just bend.

Or if your are done crashing a lot (LOL, that happens?) just put stock baldes on. Not as strong but if you don't crash, they work fine.

BTW, leveling the swash is a baseline only. My V3 hovers perfectly, yet the swash has a slight aft angle. Set the swash to whatever works (might not be level).

Hope this helps.

RE: Co-Comanche
 

I guess I should have mentioned that, the blades are balanced and tracking properly. Main problem is the forward flight, almost non existant. Push the cyclic forward all the way, heli slowly moves forward several feet then stops and rolls to the left. Even with you holding the cyclic dead center full forward. Basically push the cyclic straight forward, heli moves slowly forward several feet stops then rolls to the left? NOWIND and inside. Now on the other hand left right and backwards it will go like a bat out of **** you barely move the cyclic backwards left or right and it moves quickly like it should.

RE: Co-Comanche
 

Got me....

Go back to the old blades and see it it still does it.

RE: Co-Comanche
 

Yes Hotrk51, thats about where I'm at Ihave a Piccolo, and a Raptor and never ran into this situation. Never had blades make this much of a problem. Been worrying with it for 2 weeks now before posting a question but have exhausted all my ideas of the problem. Does this help you any, I have noticed now with the new blades on that the flybar tends to stay cocked at an angle to the left even if the blades are spinning but holding a hover if i bring the hover up to eye level, the fly bar is tilted a few degrees to the left and no movement corrects it, say I go aileron right it still stays cocked to the left vs versa. Even sitting on the ground running the blades up just to where the heli is light on it's feet giving no control input the flybar is leaning left but the blades are turning even. Basically if you look at the top blades there is more room between the flybar on the right side of the heli than the left on the left side the flybar is almost inside the tracking zone of the blades, Ijust noticed this in the past hour. Brand new flybar also. 7" Itried the stock one with same results

RE: Co-Comanche
 

Hi,

... if your flybar is not level when the blades are level, why are you surprised the heli moves in one direction if you push straight forward? Did you ever check if the flybar is balanced? (I once had one where one weight was considerably lighter than the other.
Also, is your flybar link long enough? If the flybar leans to one side, that might be the reason. Check and extend if necessary. to get more forward movement, you may want to go one hole further out on the servo horn ... if you got the factory cut down horns, get a set of new horns (EK2-0500A/000491)

Hope that helps

RE: Co-Comanche
 

Yeah, correct!
Level the blades and adjust the flybar to level too.
If it was fast forward before, then it's probable not the servo horns. But moving out one hole will surely make it faster.

RE: Co-Comanche
 

Ok, what I did was pulled thecontrol armsoff, re did them so that both servo horns are level off the sevo's and the the control arms going upward at 90 degrees checkec for balance on all blades, tracking and balance on the flybar.

1st. try Smashed into the wall, any input into the chopper made it wobble. would hover kinda ok. but if i put any cyclic input into it. The chopper would move but wobbled when it did, literly WOBBLE. Plus terrible blade slap "thats what made me eat the wall" LoL

2nd. Put all old blades back on. Flew great, no wobble flies in any direction now and flies quickly forwards and in all other directions.

Conclusion: THESEBLADESSUCK!!!!!! I will sell them if anyone wants them http://www.rcuniverse.com/forum/js/f...ey/msn/lol.gifLoL

Thanks to everyone that helped though, part of it was though that my servo horns had gotton so far out of adjustment, once I looked at them and before I redid them, the swash plate was level but the servo horns were pointing at 5 o'clock on the right one and 7 o'clock on the left one.

Thanks again!!!!

RE: Co-Comanche
 

Glad you got it figured out! :D :D :D

Now fly till your thumbs bleed!!

RE: Co-Comanche
 

Anyone else ever noticed that there Co-Comanche flys diagonal? Inside a small room it's not too noticeable but I was flying in a gym and after it moves forwards about 10 feet, it begins to want to fly diagonal "no matter what rudder input you put in it" I believe i read somewhere else on the internet someone else haveing this same experience but don't know if they ever corrected it. Another thing that seems to be wierd. I can't fly it from one side of the gym to the other? Iget about half way and it stops forward flight even with the cyclic full forward? Ihave to then recenter the cyclic, reduce throttle for a sec. and the go forward on the cyclic and full power on the throttle to get it moving again forwards. I have to do this a couple times to make the trip across a gym. "No exhaust fans running 0 wind or draft" Basically fly forwards 30-50 feet, it stalls out even with the cyclic being held forward. recenter the cyclic, reduce power, push the cyclic forward again and at the same time full throttle and once it starts moving, adjust power. You have to do this over and over again to make a trip across a gym. Any suggestions on either issues. hovers great, no drift in any direction. I've just been lucky the past few days being able to fly in a gym and have noticed these quirks. And when Isay it flys diagonal, i don't mean the tail is comming around, it's flying kinda like a car going down the road with a bent frame. A little cockeyed.

Thanks

RE: Co-Comanche
 

Hey again Batty33Res,

The coax FF phenomenon that you are experiencing is due to the flybar "pulling up" (constantly fighting & finally winning the constant stuggle that the flybar has with) your inputs in the Tx. The angle of swashplate via input/flight is something else. Let me try to explain them as simply as I can.
When you input into the cyclic (RH stick of a mode 2 Tx) your input signal goes via the electronics of Rx (pickup), mixer (spits signal between the servos and the ESC controller of the motors) and the gyro which tries to keep everything in balance. The Flybar essentially flies the upper rotor pair while your inputs directly affect the lower rotor pair - so you see the flybar is fighting to keep the bird in hover while you are fighting the flybar to maintain FF. The obvious answer is to lower the authority of the flybar over the upper blade plane so your inputs are stronger! You may do this by lowering the amount of weight at the ends of the flybar - which is (due to rotational kenetic energy or torque;) and centrifugal force) maintaining quite a strong hold on the upper blades.... The authority can also be lowered by lessoning the distance from the hub that this weight rotates.
Now a brief explanation of your second observation:
When cyclic is inputted, the appropriate servos moves and tilts the swashplate in a direction. Now, comes the extra difficult part to explain simply. Due to a couple of very tricky physics principles of rotary flight, the lift of the blade isn't perfectly immediate - and this 'lag' is accounted for in the design of your coax by the swashplate not seeming to tilt exactly forward/reverse & left/right when inputted so. Instead the swashplate tilts at a combined angle:D Does this make sense so far?:)
If you are interested search " dihedral of lift " and " gyroscopic progression in rotary flight " - very involved but interesting reading[sm=49_49.gif]

Peter[sm=shades_smile.gif]

RE: Co-Comanche
 

Peter, always a pleasure. Thank you for always helping me and not getting bothered my my questions. Iput a 7 inch flybar on my heli and tried it but still the same results. The heli will begin to go forward but after 20 or 30 feet but the does a nose up flare. I tried doing everything Icould tonight to figure out the problem but it ended up in a crash into a concrete wall at about 15mph crushing the canopy, landing gear and blades. no prob though cuz I have spares of all. My main problem is Ihave no forward flight basically. If Iease it i have a bit "say if i was in your living room and wanted to fly it to you just a couple feet away" but other than that Ihave none! Believe it or not when i was fighting it, when i pushed forward on the cyclic, it would go forward a couple feet the go backwards??? I would actually let off the cyclic and it would inch forwards, push the cyclic forward and in would jump forward, flare nose upwards then go backwards. Thinking about throwing it in the trash!! Any suggestions?

RE: Co-Comanche
 

Hey again mate,

I always have suggestions: 1. Keep it away from the trash!:) 2. You will always get more servo throw by moving where the control arms make a join to another (outwards) hole in the white servo arms. But be cautioned now. If you move it too far out (eg. the last hole) the movement can either allow the control arm to bind on the edge of the swashplate or not make any more diff. to the cyclic. Worth a try if you have any more holes to play with. A pic or two of your servo settings now would make it easier to make accurate suggestions.........:D

Peter[sm=shades_smile.gif]
P.S. You shouldn't need to purchase anything more if it has full-length servo arms - just adjust the settings you have[sm=49_49.gif]

RE: Co-Comanche
 

Well Peter if I may ask, could a weak battery cause these problems? My battery is only allowing me to fly for about 3-4 min almost wide open or atleast 75-80%power just to fly. NOONEhas a battery in my area. I'm waiting on a new battery via. mail. Could a weak battery cause my problems with my flight. Ihave a 6inch flybar but same problems as before. Is it that I can not keep my rotor head speed up? Like I said Ipush forward and it goes forward then flares up noseward then wants to go backwards. I can fly backwards great but not forwards much only in small distances. It goes a little bit then stops with the cyclic pushed all the ways forward. I let off the cyclic and then its lunges backwards stops then hovers perfectly still? could it be the battery I have cant keep up with all the demands of whatI'm aksing of it? I'm not used to a coax heli. the last heli I owned was a Piccolo and I'm used to just pushing the cyclic forward and doing gun runs? thats what I'm trying to do and it won't do it? I want it to fly 50 feet forward, spin it around and fly back but it wont even do that? just flys forward's about 20 feet then stalls out. I know it's not a single rotor head but out of the box it would fly forward until i stoped it now it just wants to stall when I push it forwards after a few feet. The tail drops bad and it noses up.

RE: Co-Comanche
 

Hey again mate,

It is possible I suppose![sm=50_50.gif] But more than likely it is just out of adjustment[sm=72_72.gif] due to heavy landings during the learning stages of your journey[sm=omg_smile.gif] From your detailed description, it does sound like the flybar is fighting hard and winning the battle:) - it seems to bring the bird under its control after only a "small distance". If it was only the lipo amps are low (leading to shorter flight times;)) there wouldn't be much of a leap from sudden throttle increase......you could always test out that theory - carefully!

It is true that the single-rotor FPs don't have the coax probs - but (I assure you:D) they have their own set of probs.........:)

Peter[sm=shades_smile.gif]
P.S. Just a thought: Have you adjusted the top link so the upper blades while spinning form one "plane"??

RE: Co-Comanche
 

Tracking is good top and bottom, out of the box, Ihad to put the trim tab on the cyclic full forward to hold it still in a hover, now that Ihave redone it the cyclic and aireron are both almost center to keep it still in a hover. Peter it almost acts like Ihave a ton of weight in my tail all the sudden. Like I said out of the box Ihad to trim it full forward to keep it still in a hover. Iredid my control arms to try and bring it closer in range and now Ican keep my trim tabs close to center and keep the bird in a hover "my tabs are not at there full range" but whenIgot it out of the box it would fly across the yard like a bat out of h*ll and now it keeps doing the nose up crap after a few feet. even while holding the cyclic full forward. I'm thinking about re doing the swashplate so that it's tilted a little forward even in a normal resting postition.? Whats your input on this. It hovers great but forward flight it wants to make nose up flight, "fly foward a few feet, nose up then tail up" a rocking affect.

RE: Co-Comanche
 

Hey again mate,

Where is the servo arms in relation to the control arms? 90º? Or are they like belows pic shows?

Peter[sm=shades_smile.gif]

RE: Co-Comanche
 

Hello, yes just like in your picture

RE: Co-Comanche
 

Hey again mate,

Adjust the control arms to tilt the swashplate forward then. You can remove some of the permanent FF with the trim on the Tx. See what eventuates.......:D

Peter[sm=shades_smile.gif]
P.S. The next thing to do is relevel the swashplate by eye - then loosen the screw at the center of each servo arm, pull the arm to the head of the screw and move the arms orientation to be closer to 90º than it was before. Beware the spline on each will stop you putting exactly where you want........;) Don't forget to re-tighten the screw:) NB THIS IS ALL WHEN THE SWASHPLATE IS LEVEL BY EYE - a great starting point[sm=49_49.gif]