Multiplex Funcopter

[tower]

Hi
I am probably to anal to fly it that way - On mine the tail is a blur and the vibration appears to be affecting the gyro significantly. The remote reciever on the AR7000 shook free last night. Like you I planned to teach with it. In its current state it is the toughest heli I own to fly - its all over the place.

In my continued late night vibration-a-thon I am here (note I just sent to Multiplex asking for direction);

"I am beginning to suspect an out of the box failure on the main shaft (S – two pieces?) – I do not have a dial gauge but my best effort with a micrometer reveals approximately 7-9 thou of wobble in the shaft above and below the main gear. It is quite noticeable if you rest a screw driver tip against the shaft and rotate it - from the high to low point a significant gap opens up.
I cannot get the head to balance without the blades on (and the tail completely removed) and once the blades are on the unit is shaking badly. No amount of adjustment with balancing tape on the flybar or main blades seems to correct this."

4:30am - time to give it up for now

[tower]

Multiplex is shipping a new main shaft assembly to try.
Stay tuned if you are tuned

[RocketManRC]

I am very interested to see if you get a solution that is to your satisfaction Jeremy.

Rick

[tower]

It turns out that main shaft not the problem. With the help of my local dealer, who supplied a second unit to compare with, I think I have tracked it down. The second heli has the same problem. I tracked the blades on both heads and they are now fine.

Here is what I think is causing the issue - http://www.youtube.com/watch?v=2ObWGsQObqI

[Dirt Torpedo]

Nice video. Rick and I should both give it a shot but I think the conclusion may be inevitable - mishapen main gears.

Great work.

[tower]

Hi Folks
Well I finally gave up on the funcopters. In the end just too many problems. I have had several conversations with the tech support team at multiplex USA.
My sense of the issues;

1) The Head is difficult to balance - it can be tracked but the head overall may be unbalanced and does not lend itself to being corrected in a conventional way - it does not work with my balancers which are fairly standard. The low RPM motor makes the problem more noticeable - as head speed increases the wild vibrations that can happen if you have a problem in a 450 size heli or larger tends to even out a bit - since you don't get to high RPM in the funcopter the thing just shakes like an elvis bobble head doll. I have tried balancing tape (lots of!) with some success and this may have worked better if it was the only problem.

2) The main gear (on the main shaft) in the two I had (they are gone now) were not molded properly and wobble - see previous posts. Multiplex does not have a solution for this. The wobbling gear interacts with the tail gear and appears to create a vibration in the frame and particularly in the tail. Also the wobble throws the main shaft out of true and causes the head to vibrate.

3) Middle Bearing - the bearing half way up the main shaft is not well supported. In a Trex type Heli this bearing would be locked in place and secured with a metal carrier. On this heli is it pushed into an open sided plastic seat and does little of anything as far as I can tell.

4) The wire in the tail that drives the tail rotor is known to whip and bow. It is supported in two places - the supports can move. The whipping is a known cause of vibration in the funcopter.

5) Undersized components - It may be argued that both the main shaft and the tail drive wire are undersized for the load they bear. They are flexing and amplifying problems.

All In all;

The quality is not there – A trex 450 sport can be had at lower cost and the quality of the Trex is miles ahead of this machine. True, the application was supposed to be a very rugged “fun”copter – well I didn’t have any fun. In the words of one of the Multiplex support folks (paraphrased) "This heli is for flying straight ahead, not for hovering around". I suppose you can't see it shaking itself apart from a distance?

Cheers

[RocketManRC]

The Funcopter has been my biggest disappointment of any R/C product I have ever bought. Well maybe the Aerobird Swift was a close second. Lol.

I took some video of mine for Jeremy when I checked the blade tracking on the weekend:

http://vimeo.com/24416939

The tracking is fine but watch the tail and the receiver shaking!

I think it needs to go on a combat mission this weekend. Are you up for it Steve?

Rick

[steve]

Im thinking Funcopter and Mugi.........I said goodbye a long time ago !

This weekend....behind the school.....be there

lol

Steve

[RocketManRC]

Woohoo! I will be there rain or shine.

[RocketManRC]

Seems I better practice with this stupid aircraft before the weekend. LOL.