Now when i lift off the ground, it goes up and down foot or two pretty violently, almost constantly, without any input from me. Making it pretty much impossible to fly. Anybody know what is wrong?


Thanks!

sticky collective... do a search on the web. and reverse the shims in the blade grips.

Could also check and make sure that the pitch on your blades is matched.

- Check the pinion's mesh with the main gear
- then check the main gear...give it a feel and make sure it's not out of round or shorn anywhere

If even a *single tooth is shaved off, it'll skip per revolution causing the bouncing you're talking about.

- Additionally make sure you've done the sticky collective fix to rule that out as a possibility
- Out of track blades and slop in your links will also cause the blades to flip back in and out of track simulating a sticky collective problem. You'll hear sort of a "whoomp" the blades will snap into track and the rig will shoot up like a rocket

Hey thanks for the info.. But now can someone tell me how to get the grips off?

Thanks!

you need 2 1.5mm allen keys one for each m2 bolt on either side of the spindle

ok it seems that it will hover if i dont touch the controls at all, but once i make a correction.. it drops like a rock! Im about to give up on this piece of junk.. so any last efforts on getting it airborne will be greaty appreciated

I have seen alot of posts about this yo-yo type movement in the CP Pro now. I am starting to think that there may be a little more to it than the "Sticky Collective".

My CP Pro right out of the box has these up-downs, which I have never experienced with my regular CP. I have torn my head apart, checked bearings and such, put silicon lube on the spindle and o-rings and still have the up-downs.

Well, I braced the little heli so it would not take off under 3/4 to full throttle. I can clearly see the blades rocking towards the ground at the front of the heli and towards the tail boom at the back, as the rotors are making revolutions. I think this is exactly why I have the up-downs.

I have not crashed the heli at all, so this makes me think the head is slightly defective. Could be a bad batch of them from the plant???? There seems to be a lot of play in the head, when I push down on the blades. The only thing I can compare it to right now, is my TREX's head. This is not really a fair comparison.

Welcome to the wonderful world of the BCP. Erratic flight characteristics such as these are simply unavoidable with it's design. It is possible to get it 'dialed in' fairly well for a few flights, but then the trouble returns. Best thing to do is to get a better heli IMO...

Once I got my Falcon 3D ($279 RTF from hobby-lobby.com) and put a few flights on it, my BCP went on the shelf forever...


But for the yo-yoing, If the collective is not sticking, blade tracking is OK, and you are sure there are no stripped teeth in the servos, then check the head dampening. If it's too loose, it will do this badly. If it is loose, you can add a shim or two in front of the o-rings to 'clean it up', but like I said above, it will probably return after a few flights...

I had the sticky collecitve problem when I first got my CP a year ago, but once I got 3BB blade grips and got the washers in the right order, it left and never came back. I have since upgraded to a Bell-Hiller and LiPo and have hundreds of flights on my CP with zero problms with the head (I have to re-set tracking from time to time, but that's no big deal). Over the past year I have replaced a couple of spindle shafts and blade shafts, but other than that the Bell-Hiller mixer setup has held up great. I am flying with a slightly stripped front servo now and it still flies fine, the servo seems to recover nicely from the missing teeth. I have to get that fixed.

I also have to agree that I don't think my blade will be getting much air time now that I finally got my hands on a Falcon-3D. What a difference. As my wife said, "Now that's a helicopter!". I was out flying figure 8's last night and the stability is just outstanding. The tail won't move unless I move it period. I guess you might get this with the Pro and a HH gyro, but I love not having that silly tail motor.

Steve

do you mean the tracking is off? If so, than look in your manual, it will explain how to fix it.

Br4,from your posts, it seems you may be new to flying these heli's. If so, I would add the recomendation thet you follow the Radd's School of Rotary Flight. Great lessons, aLOT less damage on the way to learning how to fly these things. Andy

Sox101,

The tracking is spot on. I had the CP for about a year and then went to the Pro. I have upgraded to a brushless system, but the up-downs even happened with the stock motor. My next step is to take the BH head off and put the regular head on, to confirm if my BH head is goofy.

one more suggestion... i've had this 'once touch stick then drop' sydrom. DO NOT TIGHTEN THE SCREWS ON THE MIXER ARM TOO TIGHT. make sure that it'll move freely. and try adding a shim or two between teh orings and the bearing shim. if you get a somewhat nodding effect afterward... remove a shim... hope this helps.

Good point chopperdudes,

I also have found the screws in the mixer arm do matter on flight characteristics.

Just got done adding a shim at the o-ring. Up-downs still there. I can fly it this way, but I know how solid my regular CP could hover, so that is what I am aiming for. I am sure the up-downs are costing me a little in total battery-flight time also.

I know that once the up-downs are solved, this heli is going to be very smooth. I have my throttle and pitch curve matched well on my radio. I have a dual tail set up, which is holding the tail very nice. Obviously not a good as my Rexy, but pretty darn good for not having a HH gyro. In no way I bashing Horizon or the CP. These helicopters fly very nice when you get them set up well.

Yeah my blades do the same thing.. in and out of track sorta, so im guessing thats the problem. Im just going to take my heli to the hobby shop and say "fix it please".

I could fly the heli just fine before this happened. I didnt even crash my chopper since it flew and since this problem occured. I could easily get 30 second hovers in a 6x6 space, and at times it would be rock solid and wouldnt even move! But now i cant even lift off

So thats what im gonna do, see if the hobby shop can fix it. If not im gettin on the horn with horizon and seeing what they can do.

Ok,

Just put the regular head on the Pro and the up-downs have gone away. Solid hovering, but the only problem is I was spoiled by the responsiveness of the BH head.

I will get with Horizon to see if they will replace my BH head.

What exactly is the "head"? Is it all of those little black parts that connect to the blades?


At least i have the terminology down

the head is the whole "spinny thing" (<--- highly technical helicopter terminology HTHT). [8D]

Do you know off hand if Hobby Town sells spinny things? Im anxious to get my bird in the air

I'm sure they do but ;

What worked for me may not be the same fix for you. If you decide to replace the BH with the regular head, prepare to have the heli feeling like it is more sluggish.

Hope you find a fix you are happy with.

I don't really have enough experience with this heli to notice any performance differences yet. So I'm just going with the regular head. I'm about to leave for Hobby Town so ill report back later tonight!