Fury - Plastic Fan's, small cap screw ejected!

[david.read]

Hi all,

Quick post to say that the other day i heard a slight click from my Fury Expert whilst hovering it. Moments later it started to run slightly erratically and lost some power. I landed it quickly and looked over it, without taking the canopy off, everything looked normal.

I began to hover again, and noticed a lack of power, i again landed it and touched the base plate and found it was quite hot. After CCW of the main needle i flew the remainder of the tank and landed without event. I say without event, but during the flight my tail started to kick, more than it usually does (GY601).

When i got home, i removed the canopy and saw a hole in the shroud that directs the air over the heat sink. I know this object came from the fan, as i could see it. I have removed the other cap screw, from the other side and found that the fan is also bonded to the uni ball thing.

Long winded, but this is a factory fitted part, and I'm just thank full the screw didn't go into the carb.

First post - Regards,

David Read

[DavidH]

Did the head of the screw snap off or did it unscrew from the fan?
Also with the engine running hot all of a sudden, I don't believe that was caused by the screw coming loose. Since the fan was not slipping on the hub as you said the other screw was still in place.

David

[david.read]

Hi David,

Thanks for the reply.

I thought that the hole in the side of the fan cowling could have prevented some of the airflow over the heat sink, thus assisting in the overheating symptoms of reduced power and the tail kicking slightly.

To answer the first Q: The screw unscrewed from the hub.

David, can i ask, should the screws be tapped into the hub, or do they just butt up against it? The reason i ask is that my fan is glued as well, and there are no holes showing now that i have removed the allen screws.

I'm also trying to get to grips with my 601, but I'm scared to post yet another PM on this.

Regards,

David Read

[DavidH]

The holes should be thru the fan and into the hub. The allen bolts on each side should thread thru the fan and into the hub. I don't believe MA uses glue when putting the plastic fan on the metal hub. I have watched them assembly fans a few years ago and I don't remember them using glue then. But they may use it now. Usually the hub is just press fitted into the fan and the bolts are installed to hold the fan in place on the hub. The bolts have loctite put on them when they are threaded into the hub.
Don't know how big a hole you had in the side of the fan shroud. But I believe it would have to been a pretty large one to make much difference in how the motor ran.

What is your problem with the GY 601?

David

[david.read]

Thanks.

I bought it second hand from a guy at Midland Helicopters here in the UK. By all accounts he is an expert flyer, so i guess he may have guled the fan to the hub as a kind of belt and braces thing.

All my gear is JR except for the gyro, which is the GY 601.

I have the gain at 38% on both AVCS and Normal. (I believe this is the reccomended max) by somebody called JK. ( Only joking!).

I get a very crisp hold/ stop on a left tail input, but a bounce on a right tail command.

From the servo position i installed the ball onto the futaba disc on the outer hole but gatther this is slightly too far from the center point of the servo, thus limiting the end point to 108 in both directions. (I have heard that this value should be the higher the better. - To extend the servo life.

Everything elce is pretty much as it comes. Please find a quick overview:

PS I use a JR 9X and understand that the %ages differ from Futaba, so the AMP values can be slightly higher.

37 N
38 A

G: 2N 100%

NCG (B) 130%
NCG (A) 120%

DI IA 0%
DI IB 0%

DI DA 0%
DI DB 0%

Trk: +0%

Mode: CMT

F Mod: F3C

AVS 50%

Lmt B 108%
Lmt A 107%

With these settings i can get a waggle in the hover, but not like too high a gain waggle, more like a drift and then a compensation back to straight. Sorry it's slightly hard to explain.

I'm new to the sport, say 1 year flying and half again on the sim.

I also appreciate that a vibration could upset the sensor and cause it to move.

David :)

[DavidH]

The AVS setting looks a little low to me. I have not went and looked at mine, but I just don't remember it being 50%. AVS controls how the gyro stops the rotation.
Moving the precentage one way will allow the model to drift to a stop from rotation. Moving the precentage the other way will make the stop more abrupt.
I adjust the AVS mode to suit my personal timing of the rotation.

You might also want to change the foam tape under the gyro sensor and see if that helps.

If the wheel on the tail servo is the Futaba large wheel that has the holes 19.5 mm out from the center around the perimeter of the wheel. I will suggest moving the ball inwards to around 16-18 mm. That should give you a little more resolution of the servo and also allow you to increase the gain slightly. No problem running it at 40-45 % that I have found.

And yes vibration can affect the gyro. Mounting location and engine running smoothly is critical to gyro performance.

David

[david.read]

Thanks David,

I will fly and try and post with another reply.

PS# The tape i'm using is the JR tape for the 5000T. It has a slot in the middle, this helps i've been told, in the prevention of the tape splitting round the edges and the gyro falling off.

I guess i thought the AVS was the piro speed of the gyro, so i lowered it just in case the fuel became dizzy.

Thanks David.

David :D

[DavidH]

NCG (B) 130%
NCG (A) 120%


These settings here will increase or decrease the pirouette speed. This is the Channel Gain settings .
The N in the front is when the gyro is in Normal mode. When it is in AVCS mode there will be an A as the first letter. The A and B at the end is the direction the stick is being deflected.

This setting is really so that the pirouette rate can be made the same in Normal and AVCS mode.
I just set the precentages about 200% in all settings ACGA and B, NCGA and B.
Then I use the ATV on the rudder channel to adjust the pirouette rate I prefer.

This gyro was designed so that a person with a basic 6 channel radio. Would have the same capablilty of adjustment as a person with a 9Z radio. That is why most of that stuff is in the gyro. I use the delay feature on the rudder channel of the 9Z radio instead of using the DIA and B and DD A and B in the gyro menu.
Delay will also adjust how the stops are with the GY 601.

David

[kthane]

Been there, done that. Whole screw departed. I noticed my fury was whistling while idling. This was due to a gaping hole in the shroud.

[david.read]

Thanks David,

I beginning to understand it now.

I will post in a seperate topic when i test it out.

David :D