Hi All

I am new to helicopters and am starting out with the Blade CX. So far it is great, I can hover and fly pretty well as long as it is nose out.
However, I did break the lower roter head and needed to replace it. I have a few questions regarding it and the associated pieces.

1. There does not seem to be any flat spot or hole in the outer roter shaft for attaching the lower roter head with the 4 screws. Is this just a tighten as much as you can piece? At a certain point the screws just spin but they does seem to prevent the head from moving.

2. How do you know what height on the shaft to position the lower roter head? I positioned it so the lower swashplate was about level and there was a small gap between it and the outer shaft retaining collar.

3. Should the lower roter head be able to move vertically? I know this is a very basic question, but I want to make sure I do this correctly. Right now mine is tight on the shaft and cannot move vertically.

4. This is a big one. I cannot get the lower swash plate to stay flush with the upper swash plate. My first question is should it stay flush? My guess is yes, and based on the pictures I took prior to replacing the part, that was the case. After I replaced the lower roter head, everything was fine for about a day. Now, as soon as I apply a little throttle and then move the right stick, I can see the lower swash plate fall down and rest on the outer shaft retaining collar. Once this happens, I have no right stick control.

What normally keeps the lower swashplate snug against the upper one?

Any help any of the experts on this forum can give me is appreciated.

Thanks

EXW

Hi EXW-

Don't worry, there's a lot of people here who can help you out. So, let's get started!

Yes, just tighten them as much as you can... but be very careful not to over-tighten! If the screws are spinning in place, you are getting pretty close to stripping out the screw holes. Just screw them in until they are finger-tight, and that will hold the lower head in place just fine.



You're probably fine here. Make sure that both of your servo horns are centered (level), and then adjust the lower rotor head up or down until the swash is also level. At this point, it helps to mark the lower shaft with a Sharpie so that you know where to reposition the lower rotor head the next time you have to take your bird apart.



No, the lower rotor head should not be able to move vertically.



A separated swash plate is a typical CX problem. Same thing happened to my bird soon after I brought it home. The good news is that there's a simple and effective solution. What you need to do is VERY CAREFULLY glue the inner collar of the swash plate to the inner race (ring) of the swash bearing. I used a little epoxy, applied with a toothpick, and my swash hasn't come apart in over 90 flights since then. Just remember to use a tiny, thin ring of glue and be sure to wipe up any excess before it sets up. Otherwise, your swash will turn into a neat little paperweight, and you'll be making a trip to the hobby store.


I hope this helps!

What about the Aluminum Swashplate for the BCX (EFLH1246) ? Will it remedy this problem?

Biker-74

Taffey,

Thanks for the answers, that really clears things up. I would not have come up with glueing the swash plate to the swash bearing.

I don't have my heli with me right now so I'm trying to visualize this. I'm sure it will make more sense when I get home and have the CX in front of me. I don't want to end up glueing the wrong pieces together, particularly in that area. [X(]

One more question while I'm at it. What should I expect for flight times on the CX? Right now I get about 5 minutes out of each of my two batteries (sometimes less). One factor is that I live at about 6,000 ft. However, I'm not sure if even with the altitude factored in, I should be getting more out of the batteries.

I thought it might be that my gears were too tight, but they seem to have the recommended play. I also added a heat sink to the motors.

As always, any advice is appreciated.

EXW

My cx swashplate is separating also. Will try the glue fix.

Their should be a hole in the outer shaft. I believe that the top hole of the lower head should line up with this hole. Then you adjust the control rods to make the swash level. Little trick unplug the main motors and center your trims power the heli up so the servos are in their neutral position then adjust control rods to make swash level, unplug heli reconnect motors and go fly.

Yes indeed THERE ARE holes in the outer shaft for the TOP two screws! The bottom two just need to be tightened against the shaft a bit. Needless to say, this will auto align the rotor head on the shaft where it belongs. When you have everything all assembled back together, simply press the two halves of the swash plate together, it should 'snap' back into place for you.

Thanks for all the replies everyone.

I looked at the shaft a couple of times and could not find any holes or flat spots. This is the original outer shaft. Is it possible to put it back in upside down?

I have pressed the two swash plates together and they snap in place. However, as soon as the throttle is going a little and I use the right stick, the lower swash slides down.

It looks like I have a few things to try this evening.

Thanks again.

EXW

I don't have any experience with the aluminum swash that is available, although I imagine that it would solve the problem.


The control rod length and servo horn centering should have been taken care of at the factory. All CXs are test-flown before they are packed up, so I wouldn't worry about any of this unless you are doing a major rebuild, such as after a particularly nasty crash.


Actually... there may not be holes in the lower shaft. I have seen at least one other CX that does not have holes, so it's entirely possible that EXW's bird does not either.

Oops, I forgot to answer this one in my last post. It is entirely possible that the high altitude where you live is lowering your flight times. I fly at sea level, so I don't have any first-hand experience, but I have heard of this problem with helis before. If you think about it, it makes sense. Because the air is thinner, the blades need to spin faster in order to create enough downforce to keep the heli off the ground.

Another factor is training gear. I was getting 7 minute flights out of my CX with the training gear attached, and now that it's off I get 10 to 11 minutes per flight. If I spend the time to completely balance the rotor heads, I get 12 minute flights

Well, thanks to all of the advice here my CX is back in business.

I decided to take apart the rotor and see if I had somehow missed the holes. Once I removed the lower roter head, I saw that the shaft did have holes but..... (wait for it).......the lower rotor head's top two holes did not go all the way through. Both top screw holes were blocked by plastic. Not only did this block the holes, but it kept those screws from ever coming in contact with the shaft. I didn't pay attention to the holes when I was changing the rotor heads and after it was on, it was hard to see.

So, a pretty dumb mistake on my part. Like a lot of problems, the answer was simple but the process of finding it was long. Once I drilled out the plastic, the rotor head mounted correctly, which in turn locked the swash plate in place. The CX is flying well.

On the plus side, I did learn a lot about the CX. I took apart every piece along the shaft, so it was an education.

Taffey, thanks for the input on the flight time. I do have training gear on so that is probably contributing, along with the altitude.

Thanks to everyone for the suggestions. It gave me a lot of insight into troubleshooting the CX.

EXW

EXW, GLAD U LEARNED ALOT. HERES YOUR NEXT TIP/STEP
UPGRADE TO THE ALUMINUM SWASHPLATE AND MOVE YOUR SERVO
HORNS ONE... YES ONLY ONE NOTCH FURTHER DOWN THE SERVO ARM
THE STOCK SWASHPLATE IS PLASTIC AND HAS SOME GIVE TO IT AND WILL FLEX. WITH THE ALUMINUM ONE AND MOVING THE SERVO HORNS A NOTCH FARTHER YOU WILL NOTICE YOUR BIRD CAN MANUEVER BETTER AND HAS GOOD RESPONSE. TRY IT WHEN UR READY U'LL BE SURPRISED HOW MUCH FASTER AND BETTER THE CX WILL FLY!!!!

Thanks Neo. I have been thinking about upgrading to the aluminum swash plate and lower rotor head. If Ido, I'll try that adjustment.

EXW

I bought an aluminum swash plate and it separated too. So I glued it carefully with CA and have had no more problems. If you go to longer control throws you will get more response but you will also increase the chance of a blade-to-blade strike (uppers hit lowers) and the little flybar holder may also break.
Hint: take out the screw in the plastic flybar holder. The flybar will spring out on crashes instead of breaking the holder--most of the time. Eventually you'll get the aluminum upper hub, and by that time you won't be crashing as much.

I've had a few occasions where the plastic flybar holder pops out during flight. Of course, this creates a very bizarre flight pattern. Like flipping over back-wards, spinning to the ground and such. The first time it happened I laughed at it, but after a few times it's getting boring. Repairs are fun in a way, but only as long as it's myself doing stoopid things. Not when the heli falls apart on it's own.

Does it suffer from schizophrenia or something? Why won't it remain a single heli? Why split in two like that?

Serious questions:
[ul][*] Anyone else had this behavior?[*] Any known remedy?
[/ul]

My LHS should get the aluminum parts in the end of the week, but I'm still puzzled by the fact that it does those things to me.

Biker-74

Long time ago I was a passioned high-mountain climber. In 1987, when I was climbing in Tajikistan (probably not possible any more) I had the un-fortune to get hit by high altitude illness at around 6100 meters of altitude. I managed to get down to base camp at 4500 meters on my own. (Took me three days to get down.) From there, they organized a rescue heli to get me out.

The heli took off from our valley by hovering on the ground-effect for a small while, then taking forward speed for about 200 meters fast forward. With this, the pilot managed to get some 30 to 40 meters of altitude. Then he started to circle the valley around, slowly climbing higher and higher. He finally managed to get above the 'entrance' to the valley, I believe it was just below 5000 meters, and get out of the area. Was I glad to get back to Europe?

At the time I knew even less about helis than I do know, but people told me that helis shouldn't even be able to get there. And even less get out of there. (Of course, tajikistani helis were probably not of todays European standards. And that heli wasn't really brand new either. ;-)

Biker-74