Blade CX2 Problem - No Lift, spinning counterclockwise

[yohan753]

Howdy folks,

Fist off, sorry for posting this twice, but I didn't see this subforum.

I tried running a search, but couldn't seem to find anyone with the same problem I'm having.

My Blade CX2 is doing something weird. It is basically getting about 1cm off the ground and spinning counter clockwise at full throttle.

I've had a rough landing or two, but nothing major. I've also inspected things, and there dont seem to be any broken parts (I'm no expert though ) .

I also bought a replacement battery with no luck and replaced the transmitter batteries with no luck.

Any of you have any advice for me? I'm thinking about taking in into the shop, but I'd rather not. Thanks so much for any suggestions!!

[robster38]

Is the entire helicopter turning or are you saying the blades are reversing? If you adjust the rudder trim it should have an effect on the rotation. If you have your control trimmed all the way, disconnect the battery and adjust the mixing control on the 4-in-1 control. You do this by removing the canopy, and using a very small screwdriver to turn the little white screw accessible through the hole in the 4-in-1. Be careful as small adjustments make drastic changes. I think they recommend 1/16 turns at a time and try it to see if it's better or worse. If better continue 1/16 turns until perfect, if worse, you turned it the wrong way. If you have a manual i think it explains this a little better than i do, haha

[yohan753]

Yes, the entire helicopter is turning. I know about adjusting the 4-in-1. I'll try that when I get home from work. It just seems like a drastic change in the CX2's behavior. And its not getting off the ground either.

Thanks for the suggestion.

[Laszlo]

Originally Posted by yohan753

Howdy folks,

Fist off, sorry for posting this twice, but I didn't see this subforum.

I tried running a search, but couldn't seem to find anyone with the same problem I'm having.

My Blade CX2 is doing something weird. It is basically getting about 1cm off the ground and spinning counter clockwise at full throttle.

I've had a rough landing or two, but nothing major. I've also inspected things, and there dont seem to be any broken parts (I'm no expert though ) .

I also bought a replacement battery with no luck and replaced the transmitter batteries with no luck.

Any of you have any advice for me? I'm thinking about taking in into the shop, but I'd rather not. Thanks so much for any suggestions!!

Hmm... when did this start - after a 'no major crash'? I think your upper blade does not 'carry its weight'.

Here is my guess: Your upper blade does not respond, (it will not accelerate to proper rotational speed) hence does not provide lift - therefore you have no lift - and it fails to counterbalance the rotational force of the main blade - therefore your bird goes counter clockwise.

Here are some diagnostic ideas to consider:
1. Power on TX - with rudder, elevator and aileron trims in the middle - and the 4 in 1 as usual.
2. Make sure the radio (TX and RX on the 4 in 1) are in sync, - green LED ON
3. Check the motor function driving the upper blade
- move the rudder trim all the way to the right and increase the throttle VERY GENTLY, do not make the bird lift off! The top blade should start turning first. Actually on my bird the main blade will stay stationary until about the 4th notch on the throttle before it starts rotating very slowly.
- reduce throttle to zero
Note that on a properly functioning CX2 increasing the revolution of your upper blade (by rudder trim or by pushing the left stick to the right) will turn the nose of the heli clockwise.

4. Just to complete the work you may want to check the motor function driving the main (lower) blade
- move the rudder trim to the extreme left and increase the throttle VERY GENTLY, do not make the bird lift off! - just like before. Now the main blade will turn and the top blade stays stationary.

Note that on a properly functioning CX2 increasing the revolution of your main (lower) blade (by rudder trim or by pushing the left stick to the left) will turn the nose of the heli couterclockwise.

Potential problems & potential fixes from easy to the complex and/or more costly fixes
1. The proportional setting on your 4 in 1 unit is out of whack. See your manual pages 32 & 33.
2. Bent inner (or outer?) shaft - will not allow the upper blade to turn freely. Not very complex to diagnose and not too costly to fix if you are handy. You will need to take your bird a part!
3. Shot motor. Need to replace the motor driving the upper blade.
4. Problem with your 4 in 1 unit - home fix but $$$

Let me know how you make out.

Hope this helps
Laszlo

[Heli Jim]

Laszlo.....Great advise

[phupper]

Sounds like a bad motor. You could try swapping the connectors for the motors (note polarity) and see if the heli spins the opposite direction. If so, remove all the blades and flybar, and run the motors. Make left/right yaw movements with the left stick and listen to the pitch of the motors to determine their speeds. If one is slower than the other, swap the plugs again and see if the same motor is still slow. If it is, suspect the motor. If not, suspect the 4 in 1.

If you have many flight hours on the heli, chances are one or both motors are getting dirty or wearing out completely (happened to me within 3 months). But even this can be fixed without new motors. You can soak the motors in isopropyl, spin them by hand, and shake dry. Then do the same with WD40 to displace any water. They'll run almost like new.

[Heli Jim]

You can soak the motors in isopropyl, spin them by hand, and shake dry. Then do the same with WD40 to displace any water.

I have heard this from other people too and my only question is
don't the motors get "gummy" from the WD-40 after a while?

[phupper]

I could tell you that after "a while" has happened. I found this tip just before my new ball bearing motors arrived, so I haven't run the "cleaned" motors more than several hours.

I think bushing and brush shavings build up in the bushings and cause binding, the isopropyl cleans this out. After that the rear bushing can't really be lubricated without flooding the motor. WD40 is thin, so it's easier to shake out the excess than oil would be.

As I found the tip, they said to run the motors while submerged in isopropyl. I know that will work, but I didn't like the idea of applying power to a flamable liquid.

[tadpole]

I had the same problem and found that the gear at the bottom of the upper sharft rod was stripped. Need to change out the gear...... Dam crashes

[vortex05]

Yeah I'm also assuming it's a motor / gear / drivetrain problem. There's not as much that can go wrong on a CX

[singingperry]

Hi Yohan! The same thing happened to me, found out the steel collar clamping the drive gear to the rotor shaft had come loose,tight enough to turn the rotor but loose enough to where it wouldn't spin it up to speed for lift. My cx2 would just sit on the ground and spin around like a dog chasing its tail. At first I thought it was a bad motor, but when I properly set and tightened the collar (its just above the battery) my problem was solved.

[yohan753]

Thanks so much for the great advice everybody!! I've been so busy, that I have not had time to try out any of these suggestions. Hopefully, i can get this thing fixed by this weekend...I'm dying to do some flying.

Also, thanks for treating this noob to the forum the way you have!!

[Spencer J]

Some tricks that solve allot of minor common micro-heli problems is to balance out the props using just a little tape on the tip of the blades to balance, and put some motor oil or WD-40 on the gears. Don't get over-zealous and drench the thing, just a couple of drops on the joints and bearings is all you need.

[Heli Jim]

It's better to use light machine oil like 3-in-1 rather than motor oil (which is heavy) or WD-40 (which isn't really an oil)

Spencer's right, though, about balancing the blades.....solves LOTS of problems

[Spencer J]

Yes 3-in-1 is great, actually that is what I use (I remember seeing blue, red and white "3-in-1" labels on my bottles now :o)

[phupper]

I wouldn't bother with oiling the gears. I tried a tiny bit of vaseline on the gears, hoping it would stick. It made the heli a bit quieter at first. I later found all the vaseline had been thrown from the gear on to the lower-inside of the canopy.

I'm not sure the gears really need lube, does anybody know?

[vortex05]

I don't oil the gears on my CP. I do oil the motor with Mobil1 0W20 and most of the other parts are greased with a silicone based clear lube (with teflon additive).

Tail motor has some really light silicon oil to help it spin better as there's not a huge amount of stress on the tail rotor to justify thicker bearing grease.

[hock8889]

sorry for long post, but here it goes...I dare someone to figure this one out..and I am shocked it isn't common as it happened with my first inner and outer shaft repair after 2 crashes.

I replaced the inner and outer shaft, but did not replace the inner shaft main gear

SYMPTOMS:post crash/dual shaft repair:
Plane has good power and lower blades spin quiet and fast (so outer shaft replacement went well), but top blades aren't supplying enough lift, inner shaft is slipping and making noise/grind. Motors seem fine, but now have very, very sloppy inner shaft with lots of play by bottom of gear/motor.
CX2 can get maybe an inch of the ground if I play with the POT and crank up the right motor. I shouldn't have to do that and it's obviously too lose at the bottom gear with all that noise. BUT WHY?

I see what looks like a bearing in the parts explosion (unnumbered) between the two main gears, but the online tutorials don't show anything there. Only the two gears and the bottom inner shaft retaining collar.

I have tried everything except new innershaft gear:
Checked step washer ridge up on top of outer shaft gear
Checked outer shaft retaining collar ridge was down.
Inner shaft spins freely (screws on outershaft not interfering).
Aligned flat part of inner shaft with retaining collar and screwed tight so it won't slip.

TWO QUESTIONS:
Will I be like Tadpole and replacing the inner shaft main gear fix all the play in the new innershaft? It almost seems like it needs a washer between the outer gear and inner gear, but I dont' have anything between them?

IMHO: A new bottom gear doesn't seem like it will take out all the slop in the inner shaft.

Will take it to LHS Monday and try new lower gear, but it's got tons of slop in brand new inner shaft now and I don't know why.

wow...i was so happy two days ago, and have been in troubleshooting hell for 24 hours..I want my CX2 candy back !! lol

-THANKS!!

[Heli Jim]

When you replaced the OUTER shaft, did you remove the little bearing that was inside the gear? This is the lower bearing for the INNER shaft.

If you didn't take the bearing out and put it in the new outer shaft, this would cause loosness of the inner shaft and maybe cause your problems.

[hock8889]

I can't believe it...THAT WAS IT!!

It felt like it was missing..if the dang thing was numbered, I would of looked for it!!

I can't believe this wasn't on this forum before....wow.

Thanks so much!!

It got it more efficient and it's quieter..but i can only get it about a foot off the ground..

[Heli Jim]

Heh heh.............

It happened to me and I remembered it when I saw your post.

The other thing that people forget is the little
washer that goes on the outer shaft before you install the shaft
into the frame.

Glad I could help. Stop back and let us know how you are doing!!

C-ya.......keep the skids down!

[hock8889]

If you mean the step washer, I remembered that.

It sounds more efficient, but I can still only get it 2 feet off the ground and she loses a bit of power quickly. I will take it to LHS and see if they can troubleshoot.

At least now I have the lower bearing in place and the gears don't grind!!

I probably need to increase the POT for the right motor now, since I was messing with that, perhaps I'm not getting enough lift.

Thanks again Jim!!

[Laszlo]

You guys are funny - well we stumble and learn!

Cheers
Laszlo

[Heli Jim]

When you adjust the pot, remember that the heli must be unplugged.

If you adjust it with the heli plugged in, there will be no effect from the
adjustment.

IT sounds like your battery isn't charged fully. Either that or something is binding and not letting the rotors work smoothly.

Hope you get it fixed soon and are back in the air!!

C-ya.......

[hock8889]

stumble and learn is right!!...I'm on vakay and this is a matter of high importance!!! Jim was certainly a vacation saver if not a life saver for me today...lol. I just reset the bottom retaining collar and pushed down on the inner shaft as I had some small play still in inner shaft. BOOM, it takes off nice and easy lift. I will be careful with the POT, she's spinning a bit right, which makes sense as I was cranking up the right motor due to bad lift so I need to turn it down a bit....THANKS Jim, and everyone else here....the info and this forum is awesome. I will keep flying till i die now!!