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Rgoh · 03-19-2009, 11:07 AM

I was flying my T250 in the morning, tail was solid, fast backwards flight, rainbow, tictocs no problem. But when I flew at night(the same day), the tail couldnt hold at all. even simple moves like flip, especially forward flip. The tail would blow out, and piro on inverted. I have not done anything on the bird since morning. And the following morning, the tail problem is still there.

I have checked the followings:
- Belt tension, no binding on tail (MH tail)
- Running JR3500/GP750 - tail servo is barely warm
- Tried zero delay, full delay, small heli, big heli modes.
- Gain on my 12FG is about 15%, I have been flying 15% all along. Also tried increasing and decreasing, no help at all.
-Carbon rod.

Anyone faces the same problem? Tail was alright one moment, and went all over the place the nxt moment. I think that mechanically somewhere must have gone wrong after the morning flights, but I jus couldnt figure out. Any help would be appreciated.

gravydrive · 03-19-2009, 11:28 AM

Depending on the temperature variations where you live you should let the gyro become acclimated to the ambient temperature before flying. Some high end gyros take the ambient temp into account when initializing but the lower-end ones (401, 750, etc.) do not.

Mikej · 03-19-2009, 12:26 PM

The pulley on my tail shaft started slipping on the shaft suddenly - it could cause similar problems. The other thing that I would check is belt tension.

str8huckin · 03-19-2009, 01:19 PM

Get the metal belt pulleys.

gixxerjeff · 03-19-2009, 05:16 PM

Yup,what mike said.If the belt is tight,could be one of your pulleys let loose.

Rgoh · 03-19-2009, 08:35 PM

The tension is good, and I am using metal pulleys. I will check if those pulleys are still in good condition. Thanks guys!

mickeyjohnston · 03-22-2009, 05:38 AM

Check the bracket that holds the tail rotor control arm. Mine came lose and I had the same problem.

conex · 03-23-2009, 11:47 AM

gp750 is supposed to work on 0c - 65c, are you flying on negative temps?

Rgoh · 03-23-2009, 11:50 PM

mickey: just checked, the bracket is good. Thanks.

conex: I am flying at a ambient temperature of about 25C.

mickeyjohnston · 03-25-2009, 07:58 AM

It sounds like something is loose. I would grab the blades and move them back and forth and check for slop. I would also check to see if your blades are to tight or to loose. Lastly, make sure it's in heading hold (green light on). Its easy to overlook due to use mounting them upside down.

03-19-2009, 11:07 AM	#1 (permalink)
Rgoh Registered Users Join Date: May 2008	Day and night differences - literally I was flying my T250 in the morning, tail was solid, fast backwards flight, rainbow, tictocs no problem. But when I flew at night(the same day), the tail couldnt hold at all. even simple moves like flip, especially forward flip. The tail would blow out, and piro on inverted. I have not done anything on the bird since morning. And the following morning, the tail problem is still there. I have checked the followings: - Belt tension, no binding on tail (MH tail) - Running JR3500/GP750 - tail servo is barely warm - Tried zero delay, full delay, small heli, big heli modes. - Gain on my 12FG is about 15%, I have been flying 15% all along. Also tried increasing and decreasing, no help at all. -Carbon rod. Anyone faces the same problem? Tail was alright one moment, and went all over the place the nxt moment. I think that mechanically somewhere must have gone wrong after the morning flights, but I jus couldnt figure out. Any help would be appreciated.

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03-19-2009, 11:28 AM	#2 (permalink)
gravydrive Registered Users My HF Map location Join Date: Nov 2007	Depending on the temperature variations where you live you should let the gyro become acclimated to the ambient temperature before flying. Some high end gyros take the ambient temp into account when initializing but the lower-end ones (401, 750, etc.) do not.

03-19-2009, 12:26 PM	#3 (permalink)
Mikej Registered Users Join Date: Feb 2007 Location: England	The pulley on my tail shaft started slipping on the shaft suddenly - it could cause similar problems. The other thing that I would check is belt tension.

03-19-2009, 01:19 PM	#4 (permalink)
str8huckin Registered Users Join Date: Oct 2008	Get the metal belt pulleys.

03-19-2009, 05:16 PM	#5 (permalink)
gixxerjeff Registered Users Join Date: Mar 2008	Yup,what mike said.If the belt is tight,could be one of your pulleys let loose.

03-19-2009, 08:35 PM	#6 (permalink)
Rgoh Registered Users Thread Starter Join Date: May 2008	The tension is good, and I am using metal pulleys. I will check if those pulleys are still in good condition. Thanks guys!

03-22-2009, 05:38 AM	#7 (permalink)
mickeyjohnston Registered Users Join Date: Sep 2008	Check the bracket that holds the tail rotor control arm. Mine came lose and I had the same problem.

03-23-2009, 11:47 AM	#8 (permalink)
conex Registered Users Join Date: Nov 2008	gp750 is supposed to work on 0c - 65c, are you flying on negative temps?

03-23-2009, 11:50 PM	#9 (permalink)
Rgoh Registered Users Thread Starter Join Date: May 2008	mickey: just checked, the bracket is good. Thanks. conex: I am flying at a ambient temperature of about 25C.

03-25-2009, 07:58 AM	#10 (permalink)
mickeyjohnston Registered Users Join Date: Sep 2008	It sounds like something is loose. I would grab the blades and move them back and forth and check for slop. I would also check to see if your blades are to tight or to loose. Lastly, make sure it's in heading hold (green light on). Its easy to overlook due to use mounting them upside down.

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