Punching full throttle from hover and tail kicks out.
#1
Thread Starter
Member
Joined: Dec 2006
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
From: Nevada,
TX
Im a newb and haven't been able to fly lately because the winds have been 30+ for the last 5 weeks. last night I took out my t-rex and was hovering around and punched the throttle and the tail would kick out from the torque and then swing back. is this normal? It feels like it has been so long since i've had it in the air I don't remember it doing this before.
I have not change any settings in the transmitter since I set it up but did have a crash a while back. (main shaft,feathering shaft,flybar,blades)
T-rex 450sa v2head hs65s 401 gyro 9650 tail dx7 with ar 6100.
I have not change any settings in the transmitter since I set it up but did have a crash a while back. (main shaft,feathering shaft,flybar,blades)
T-rex 450sa v2head hs65s 401 gyro 9650 tail dx7 with ar 6100.
#3
Thread Starter
Member
Joined: Dec 2006
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
From: Nevada,
TX
I had the gain at 75 and have flown it probably 20 times and don't remember it ever doing that. I bumped up the gain to 85 yesterday and it did not seem to make a difference. Do i need to re initialize after changing the gain or does it matter. I just set it down went in the menu and bumped it up. I will try a little more gain if this wind will ever stop.
Thanks druss.
Thanks druss.
#4
Senior Member
Joined: Aug 2007
Posts: 7,441
Likes: 0
Received 0 Likes
on
0 Posts
From: Edmonton,
AB, CANADA
you usually need to reboot after gain changes... see if it makes a diff. If not maybe your belt is slipping check the tension.
#6
Junior Member
Joined: Dec 2007
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
From: Lilburn,
GA
It sounds like your throttle curve is too low.
Are you in Idle up when you punch the throttle and the tail kicks out?
Are you in Idle up when you punch the throttle and the tail kicks out?
#8
Just a thought, since you had a crash check the belt drive pulley. It's common for those to start slipping on the drive shaft after a crash.
#10
Senior Member
Joined: Apr 2007
Posts: 2,564
Likes: 0
Received 0 Likes
on
0 Posts
From: Mooresville, NC
ORIGINAL: jbolt1
Im a newb and haven't been able to fly lately because the winds have been 30+ for the last 5 weeks. last night I took out my t-rex and was hovering around and punched the throttle and the tail would kick out from the torque and then swing back. is this normal? It feels like it has been so long since i've had it in the air I don't remember it doing this before.
I have not change any settings in the transmitter since I set it up but did have a crash a while back. (main shaft,feathering shaft,flybar,blades)
T-rex 450sa v2head hs65s 401 gyro 9650 tail dx7 with ar 6100.
Im a newb and haven't been able to fly lately because the winds have been 30+ for the last 5 weeks. last night I took out my t-rex and was hovering around and punched the throttle and the tail would kick out from the torque and then swing back. is this normal? It feels like it has been so long since i've had it in the air I don't remember it doing this before.
I have not change any settings in the transmitter since I set it up but did have a crash a while back. (main shaft,feathering shaft,flybar,blades)
T-rex 450sa v2head hs65s 401 gyro 9650 tail dx7 with ar 6100.
Jim
#11
Junior Member
Joined: May 2006
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
From: San Diego,
CA
jbolt1 = What is your headspeed on your trex? If you are in the 2200 range you need to get up into the 2600/2700 range. I had that problem running a 11T pinion, but when I went to a 13T (Medusa 28-32-3400) it solved all my problems. Changing the tail gearing might also help as it may change the gear ratio and spin the tail more. I am not sure what the mH tail drive tooth count is compared to stock.
#12
Senior Member
Joined: May 2007
Posts: 1,325
Likes: 0
Received 0 Likes
on
0 Posts
From: GARDEN CITY,
KS
ORIGINAL: JSmiley
jbolt1 = What is your headspeed on your trex? If you are in the 2200 range you need to get up into the 2600/2700 range. I had that problem running a 11T pinion, but when I went to a 13T (Medusa 28-32-3400) it solved all my problems. Changing the tail gearing might also help as it may change the gear ratio and spin the tail more. I am not sure what the mH tail drive tooth count is compared to stock.
jbolt1 = What is your headspeed on your trex? If you are in the 2200 range you need to get up into the 2600/2700 range. I had that problem running a 11T pinion, but when I went to a 13T (Medusa 28-32-3400) it solved all my problems. Changing the tail gearing might also help as it may change the gear ratio and spin the tail more. I am not sure what the mH tail drive tooth count is compared to stock.
#13
Thread Starter
Member
Joined: Dec 2006
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
From: Nevada,
TX
I haven't had much time to look at it since I posted this. I checked the belt tension and it seem to be fine. I am running the 13 tooth pinion with the motor that came with the sa kit. I mostly fly in normal mode because I am still learning. I don't believe head speed is a problem. I havent changed anything since I origanaly built it. It has been flying great or should I say hovering and slow forward flight great.
I'm thinking maybe the belt pulley is loose or some how the tail needs to be centered again or gain adjusted on gyro. I will try some things this weekend and let you know. The wind has been 20 to 30 here for the last couple months.
thanks everyone for the suggestions
Jeff
I'm thinking maybe the belt pulley is loose or some how the tail needs to be centered again or gain adjusted on gyro. I will try some things this weekend and let you know. The wind has been 20 to 30 here for the last couple months.
thanks everyone for the suggestions
Jeff
#14

If you where in normal mode when punched it then the tail is going to kick out. the head/tail speed wont be high enough. So even at full pitch the tail wouldnt grab enogh air right off the bat.
#15
Senior Member
Joined: Apr 2007
Posts: 2,564
Likes: 0
Received 0 Likes
on
0 Posts
From: Mooresville, NC
ORIGINAL: ea01bg
If you where in normal mode when punched it then the tail is going to kick out. the head/tail speed wont be high enough. So even at full pitch the tail wouldnt grab enogh air right off the bat.
If you where in normal mode when punched it then the tail is going to kick out. the head/tail speed wont be high enough. So even at full pitch the tail wouldnt grab enogh air right off the bat.
Jim
#16
Thread Starter
Member
Joined: Dec 2006
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
From: Nevada,
TX
Thanks guys for all the input. It is possible it has allways done this and I am getting a little more comfortable with the heli and never tried a full throttle punch before. Like I said before I was flying a few times a week and then went for a couple months of not flying and when I took it out I didn't remember it doing that before. I am a total newbie just learning and need more stick time. The next time I'm out I will put it in idle up and see what it does. The wind is finally calming down and I just need to try to get out every night and practice.
Thanks for all the advice. I am going to check everything that was suggested and take her out for a flight soon.
Jeff
Thanks for all the advice. I am going to check everything that was suggested and take her out for a flight soon.
Jeff
#17
Junior Member
Joined: May 2006
Posts: 21
Likes: 0
Received 0 Likes
on
0 Posts
From: San Diego,
CA
ORIGINAL: dooleyje
Hey guys as I said it is normal that the tail will kick and is a normal thing the trex will do no matter what the headspeed is. If he is using a 13T pinion then he is in the 2900-3045 rpm range. Trust me when I say this is normal. The only theing I have found to fix it is to counter balance the tail blades grips with weights. All you really have to do is to use a ball link on each grip. You use a longer blade bolt and push it through the ball links and through the grips. This really helps a lot, believe it or not.
Jim
ORIGINAL: ea01bg
If you where in normal mode when punched it then the tail is going to kick out. the head/tail speed wont be high enough. So even at full pitch the tail wouldnt grab enogh air right off the bat.
If you where in normal mode when punched it then the tail is going to kick out. the head/tail speed wont be high enough. So even at full pitch the tail wouldnt grab enogh air right off the bat.
Jim
jbolt - Just for fun put a linear 90% throttle curve in your radio for idle up. Fly the heli in idle up and try going full collective from a hover. You should have plenty of headspeed at this setting. If it kicks out then I would verify that you aren't giving any tail inputs inadvertently, and then look at your gyro (verify it is properly centered in rate mode for a consistent hover). Good Luck,
Smiley



