Collective Range creeps - doesn't hold

[supertoyz]

I took a long time to carefully set up my GT5 in a Trex 500 following both the directions and on line guides. The collective range was set to +/- 12 using a digital pitch gauge. It flew well but seemed way down on power. I'd felt it was a little lethargic for a while now so I replaced the motor with an 1800kv Viper motor....it was better but still not what I'd hoped, especially considering it lost nearly two minutes of flight time with the new motor. Today I noticed that it had a lot better climb out inverted than upright. I assumed maybe the pitch range wasn't balance so for a quick fix I bumped the servo endpoint for positive pitch from 100 to 120 and it made a big improvement. The heli was much more responsive and better balance between +/- collective. When I got home I set the endpoints back to 100/100 to check that collective range. The pitch range in the GT5 unit is at 100 as well. I setup the digital pitch guage and went to full + collective which was 11.8 and then full - which was 12.3 That's as close as I can get it using standard links with 1/2 turns. Maybe I'll get some turnbuckles. Anyway a half degree variation is pretty minor and doesn't explain the significant difference in climbout. Then while sitting and thinking about it I noticed the pitch gauge creeping. For example when I go full negative it jumps to 12.3 and then creeps slowly down to about 11.3 over maybe 10 seconds. Positive does the same thing. I've never seen this happen before with any other FBL unit. And it still doesn't explain the poor + climbout, even if it creeps down by one degree over 10 seconds it shouldn't give any noticeable effect in flight. I flew it again tonight with the servo travel set at 100/120 and it flew pretty nice with good performance both +/-. I haven't checked the pitch range at these settings, I wonder if the creeping is different when the heli is under load in the air. Any idea's?

[cyberbug001]

Hi, I was one of the first batch that acquire the GT-5 when it first came out, and let me tell you, I never experience migraine till I try setting it up first time plus there was no discussion anywhere at the time, so you can imagine!...Anyway, you're right...the reason for the creeping is because it doesn't sense any load!...once your setting is right,on your pitch menu, it won't show the same when you're out of the menu!...That's the way they are! like you said, it flies good...because you're putting a load and it uses the settings from the menu that you did. I actually left everything else at default and up to now, it's flying smooth and stable...but then again, I guess different heli needs different settings I also have it on the T500, but with an I2 (eye two) head....anyway enjoy!

[Euwan]

Originally Posted by cyberbug001

Hi, I was one of the first batch that acquire the GT-5 when it first came out, and let me tell you, I never experience migraine till I try setting it up first time plus there was no discussion anywhere at the time, so you can imagine!...Anyway, you're right...the reason for the creeping is because it doesn't sense any load!...once your setting is right,on your pitch menu, it won't show the same when you're out of the menu!...That's the way they are! like you said, it flies good...because you're putting a load and it uses the settings from the menu that you did. I actually left everything else at default and up to now, it's flying smooth and stable...but then again, I guess different heli needs different settings I also have it on the T500, but with an I2 (eye two) head....anyway enjoy!

Sorry could you explain this any more simpler as the same thing happens to me. What I mainly want to know is what pitch range will the blades is it the one it creeps to in the settings?

[ady]

hi , to set your collective , you need to be in set up mode , once the unit comes out of that , the unit will creep on the bench as you say , if its creeping when you are in set up mode , then i`d take it back , i have two and have set up many more , so slide ya finger up the slider to set up mode , set ya pitch n fly , to get mine correct , i do have different end point numbers in the transmitter , hope this helps

[almigurt]

So creeping collective is normal?

Doesn't it dramatically change cp min and max values while flying?

[supertoyz]

I don't think it's right but that's what it does. In setup mode I can set it up perfectly and then when out of setup mode and ready to fly you cant check it because it creeps. According to some of the responses here this is normal and is because it's not under load but I think thats BS. I've got a two Helicommands, a BeastX and a 3GX and none of them do that. And getting back to my original complaint I've got it setup in setup mode for +/- 12 degrees yet when flying it has much more punch inverted than upright forcing me to increase my + pitch travel to about 115 in my radio which seems to solve the problem. It flys ok but I wouldn't buy another one......Helicommand all the way.

[karlp]

If it continues to creep in setup mode or while flying there are 2 things you can do. The official thing to use is Swashplate Stick - Deadband in the Stick menu. If you increase this the creep should stop as it will ignore any signal from the Tx and use its own centre positioning. The second method which I prefer but I am pretty sure others will not is to try use pitch sub-trim. The Tx is always transmitting to the servo and holding its position so using the sub-trim simply makes a slight 'shift' in the frequency which holds the servo in a different position. It seems with some of the axes on the GT5 the frequency tends to creep and either of the above solutions should work.

[almigurt]

But why does itonly creep when having my stick at min/max? It also seems to "reset-creep position" when moving the pitch stick.

So there shouldn't be any problems while flying..
(just set up your Pitch, not having the sticks too long in min/max pos)

I think its the same issue why cyclic servo movements go far over the limit which one has programmed when the Heli is not in the air.

[karlp]

Yes, creeping at max stick on the bench / ground whether it is cyclic or collective is normal.

[supertoyz]

Still doesn't explain why max pitch changes. I can set it up, then double and triple check it in the setup menu confirming that it's zero pitch at center stick and +/- 12 at high and low stick. Then when you check it out of the setup menu you can't confirm anything because it creeps. Then in the air it has horrible postive climbouts that are very unbalanced from negative climbouts. Increasing the endpoint in the radio of + pitch from 100 to 115 seems to balance it out and solve the problem but doesn't explain the issue. I own several other brands of FBL units and none of them behave like this.

[zattan22]

After much playing with the GT5, I believe that the collective pitch can only be done base on "feeling".
Since setting pitch is not possible due to "no load".