CX2 power loss

[Kindling Maker]

Ok gurus I got a tough one. We have rebuilt a CX2 and I mean from the ground up. It has the 180 ballbearing motors, and the teeth are good the bearings are in good shape. When I test the motors with a multimeter they are pulling the rite power. The only thing that is not in great shape is one Servo and it is chattering. When we fly it though it has a serious power loss it flys great for about the 1st 2 minutes and then it just drops off. When we throw the same pack in my bird it flys great. If we put a new pack in the other bird it barely gets off the ground. We have changed the brushes on the motors, oiled the bearings, and we are at a loss. Help what could it be?

[BryMeister]

Assuming that everything is working correctly electrically, then you must have some kind of mechanical binding going on. Check both the inner and outer shafts for straightness and also verify that both of your rotors are turning in the correct direction.

[JodyJ]

Try different lower blades. I had some what of the same problem and when I changed blades I was able to fly again.

Jody J.

[jlharv]

Is the 1 to 2 minute thing repeatable, or did it just do that once?

The reason I ask is if it is OK for the 1st minute and then bad after 2 or so, what changed?

possibilities...

1. Heat, are the motors overheating?
2. Friction between shafts (as things heat up they expand or contract). So like Brymeister said, a bent shaft might not show up until it warms up.
3. Also as Brymeister said, any mechanical binding, after a while it may just take more power than you can give it to overcome the bind.
4. If it is older there may be oxidation on some of the connections between the motors and the receiver. Try to plug and unplug all of the connections to the receiver several times, this will scrape off oxidation
5. I am sure there are others that I have not thought of.

Are there any other symptoms, like does it spin as it is loosing power? That would indicate a problem with one but not both of the motors, shafts or blades. But if it stays straight, then you can pretty much eliminate things that have to work in tandem.

I don't claim to be an expert. But it is kind of like a puzzle when these don't work, and I like to think of all the possibilities of "what could cause that?"

[Kindling Maker]

IT stays straight It just doesnt develop any power, The shafts are brand new and so are the rotors, the motors are the Ball bearing 180s and they are from the same lot that mine are from and mine are fine. I am at a loss. the inly thing that I can think of is mabey the 4-1 I just dont know. BUt The guy wants to fly but wont order the parts, so I dont know.

[jlharv]

Have you considered swapping the 4 in 1 with yours? That way you will know for sure that it is the problem, before he has to spend money.


That is really a tough one. I would think that the battery is starting to go, but you said you put it in yours and it is fine, and you stick a fresh battery in his and it is not OK?

[mjws]

I had one of these that was brutal to track down a while ago. If you have a spare or a buddies handy, swap out the entire head. Unfortunately I started with motors and batteries... no change, inner shaft... no change, outer shaft... no change. Thing had all the bling... so I started swapping that out piece by piece.

Finally got it running decent with a stock known good head, and one motor was in fact weak (swapped it out). Swash was fine. The metal lower hub was the culprit, it looked perfect but would start to bind somehow after 30 seconds or so of run time. Removed it and with fresh inner and outer shafts (his were a little marked but probably flyable) all went back to normal. Just about ended up giving him the heli back with all the metal junk removed. So much for 'upgrades' ;)

What a nuisance. Only piece left was the 4 in 1 and that was out the door next.

Mike

[Kindling Maker]

Thanks Sorry I have not gotten back with everyone but I got busy. It is a real pain when you finally get a job done and then they blow a few holes in it.

[58Gemni]

Hey all. I am fairly new here. I picked up a CX2 some time ago and also now have a Trex 450. I still enjoy the CX2 so much, especially when the weather or darkness keeps me indoors.

this last weekend I was getting frustrated with the performance of my CX2 and started to swap out a bunch of parts. got a hold of this thread and started thinking about what next. Ended up at the LHS yesterday, picked up a few things.

Anyway, sorry, long story short..... I put on a new flybar, PLUS, took the linkage rod from the old one and put it on the unused side. It seemed to add a solid feel to the top blade assembly, plus it really let me track the upper blades. I then swapped out the lower blades until I got a set that tracked well. WOW, was I surprised! it flew smoother and stronger than ever. Great battery life again too.

Darn, then I had to help put one of the grandkids to bed... play time over for grandpa :bawl

[Kindling Maker]

Well we have changed everything and now we are waiting an a servo and a 4-1 when they get here we will be flying again.

[BryMeister]

Did you ever find the problem?