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miker · 07-22-2009, 04:51 PM

hello i posted this on another site but would appreciate any help
raptor 90 se jr 770 gyro ds8900g servo i cant get it to hold in climb outs or some manovers wants to go left at least 1/2 way around. set it up in rate mode and tried everything everybody said on line. and they tell u the set the gain till it starts hunting then lower it till it stops . well i cant get it to hunt. had the ball on the servo arm anywhere from 8mm to 15mm out i m not sure if i should go out futher.
thanks
mike

Badger50 · 07-22-2009, 06:49 PM

What type of radio are you using, and what is your gain set at?

Raynman · 07-22-2009, 09:09 PM

Set ATV 150% both ways - Set the gain to suit ( observe tail in flight) Sort the limit on the gyro to suit as with Expo & Duals.

My gyro is sweet! just read the manual instructions and sorted.
Guess some work strait out of the box?

miker · 07-23-2009, 04:35 AM

sorry dx7 radio, and the gains has been evey from 25 to 100 and atv are set to 150% and i tried them at 100% just to see and the ball on the servo arm has been 8mm to 15mm and evey thing in between. i see no difference in where the gain is set the heli acts the same. tail blows out . and i still cant get it to hunt. when the ball is out to 15mm i have to lower the pot on the gyro really low so it doesnt bind. all my other helis with the 401 in them are fine u can get them to hunt then lower the gain till it stops.

Badger50 · 07-23-2009, 06:04 AM

Hey Miker: Was just wondering about the radio. If you were using a Futaba, then the gain needs to be at 11-14%. Sounds like you have everything set up exactly right. Therefore, I think you just may have gotten a lemon...believe me, it happens. I know the 770 had some issues early on with the circuit boards coming loose inside the housing, which was causing erratic flight characteristics for pilots, but I think those were resolved. The only thing I can think of is to try a different tail servo to see if that helps. If not, then return it. Search through the electronics forum to see if you find any others with your problem, or call JR and see what they say. Good luck to you :-)

miker · 07-23-2009, 05:46 PM

i was thinking that last night about sending it back. i hate to in the middle of flying season but i guess its better to be safe than sorry.well i reset everything all over again and im gonna try it one mor time and if i cant get this time its gonna go back
well thanks for the advice ill see what happens
mike

JimLerch · 08-04-2009, 08:44 AM

If you can't get it to hunt, it sounds like the gyro gain channel isn't changing as expected.. have you tried plugging a standard servo into the channel you have the gyro gain wire on and making sure it moves as you change the gain on the Tx?

On my raptor 90 with 105mm tail blades and the 770/8900 combo, the ball is out 11mm from the center of the servo horn. Any further out than that and I can't stop the tail from hunting while doing nose down, upright, clockwise funnels.

Brian James · 08-27-2009, 08:09 AM

I'm using this gyro on my 90 SE as well. It works beautifully. Use the "gyro sense" screen on your dx7 set the gain around 65 (remember 50% is NO gyro). Make certain you have the gain plugged into either the gear channel or aux2, depending on what you set on the "device select" screen. Max out the atv's for rudder channel at 150%. On the D/R, EXP screen put the D/R around 40% (this is where you adjust piroette rate) and put the exp around 50% (this is creating a "softer" center) Be careful, if the gain is too high, and the piro speed too fast, you CAN and WILL strip tail gears on the stops.

07-22-2009, 04:51 PM	#1 (permalink)
miker Registered Users My HF Map location Join Date: Jan 2008	90 se 770 gyro hello i posted this on another site but would appreciate any help raptor 90 se jr 770 gyro ds8900g servo i cant get it to hold in climb outs or some manovers wants to go left at least 1/2 way around. set it up in rate mode and tried everything everybody said on line. and they tell u the set the gain till it starts hunting then lower it till it stops . well i cant get it to hunt. had the ball on the servo arm anywhere from 8mm to 15mm out i m not sure if i should go out futher. thanks mike

07-22-2009, 06:49 PM	#2 (permalink)
Badger50 Registered Users My HF Map location Join Date: Oct 2007	What type of radio are you using, and what is your gain set at? __________________ Mike: Rap-90 3D x 2, Rap-50 x 2, Fury 55, Rex-450, Hirobo Squark. *"Depression is nothing more than anger, without enthusiasm"*

07-23-2009, 06:04 AM	#5 (permalink)
Badger50 Registered Users My HF Map location Join Date: Oct 2007	Hey Miker: Was just wondering about the radio. If you were using a Futaba, then the gain needs to be at 11-14%. Sounds like you have everything set up exactly right. Therefore, I think you just may have gotten a lemon...believe me, it happens. I know the 770 had some issues early on with the circuit boards coming loose inside the housing, which was causing erratic flight characteristics for pilots, but I think those were resolved. The only thing I can think of is to try a different tail servo to see if that helps. If not, then return it. Search through the electronics forum to see if you find any others with your problem, or call JR and see what they say. Good luck to you :-) __________________ Mike: Rap-90 3D x 2, Rap-50 x 2, Fury 55, Rex-450, Hirobo Squark. *"Depression is nothing more than anger, without enthusiasm"*

08-04-2009, 08:44 AM	#7 (permalink)
JimLerch Registered Users My HF Map location Join Date: Nov 2007	If you can't get it to hunt, it sounds like the gyro gain channel isn't changing as expected.. have you tried plugging a standard servo into the channel you have the gyro gain wire on and making sure it moves as you change the gain on the Tx? On my raptor 90 with 105mm tail blades and the 770/8900 combo, the ball is out 11mm from the center of the servo horn. Any further out than that and I can't stop the tail from hunting while doing nose down, upright, clockwise funnels. __________________ James Lerch - Raptor 90, JR Vibe 500E, Gaui 550E, Xcell Razor* (*=On Loan) http://lerch.no-ip.com/atm (My homebuilt telescope site) http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project) http://www.youtube.com/profile?user=JlerchTampa (my you-tube crash videos) http://lerch.no-ip.com/Hat_Cam ("Hat Cam" for recording flights)

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07-22-2009, 09:09 PM	#3 (permalink)
Raynman Registered Users Join Date: Jan 2009	Set ATV 150% both ways - Set the gain to suit ( observe tail in flight) Sort the limit on the gyro to suit as with Expo & Duals. My gyro is sweet! just read the manual instructions and sorted. Guess some work strait out of the box?

07-23-2009, 04:35 AM	#4 (permalink)
miker Registered Users Thread Starter My HF Map location Join Date: Jan 2008	sorry dx7 radio, and the gains has been evey from 25 to 100 and atv are set to 150% and i tried them at 100% just to see and the ball on the servo arm has been 8mm to 15mm and evey thing in between. i see no difference in where the gain is set the heli acts the same. tail blows out . and i still cant get it to hunt. when the ball is out to 15mm i have to lower the pot on the gyro really low so it doesnt bind. all my other helis with the 401 in them are fine u can get them to hunt then lower the gain till it stops.

07-23-2009, 05:46 PM	#6 (permalink)
miker Registered Users Thread Starter My HF Map location Join Date: Jan 2008	i was thinking that last night about sending it back. i hate to in the middle of flying season but i guess its better to be safe than sorry.well i reset everything all over again and im gonna try it one mor time and if i cant get this time its gonna go back well thanks for the advice ill see what happens mike

08-27-2009, 08:09 AM	#8 (permalink)
Brian James Registered Users Join Date: Mar 2006	I'm using this gyro on my 90 SE as well. It works beautifully. Use the "gyro sense" screen on your dx7 set the gain around 65 (remember 50% is NO gyro). Make certain you have the gain plugged into either the gear channel or aux2, depending on what you set on the "device select" screen. Max out the atv's for rudder channel at 150%. On the D/R, EXP screen put the D/R around 40% (this is where you adjust piroette rate) and put the exp around 50% (this is creating a "softer" center) Be careful, if the gain is too high, and the piro speed too fast, you CAN and WILL strip tail gears on the stops.

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