TREX 450 Running Wild

logger1 · #1 02-04-2007, 08:01 PM

I recently acquired a TREX 450S and haven't yet tried to fly it since its mid winter here and I am learning on a simulator. I have however been carefully going over it and learning to adjust everything. All the controls seemed to be working fine and I have had it spinning over slowly without blades.
Today with the blades on and the helicopter strapped to a table I fired it up. To my surprise at first It seemed to have no response from the throttle but then it sprang to life with what appeared to be full or near full throttle.
While it seemed to responed normally to all the control surfaces I could not get it to respond to the throttle and the only way I got it to shut down was to very carefully disconnect the battery.
At this point I don't know what to check and having it go to full throttle is scary.

chaos · #2 02-04-2007, 11:22 PM

Check to see if the idle-up switch is on. It should be off for learning. It should also be off when you first spin up the rotor. If you're going to fly inverted, after getting the rotor up to speed you would switch the idle-up on so that when the stick is in the low position you have negative pitch on the blades AND power to the motor. Then, after landing, you would flip the idle-up switch back to normal to bring the blades to a stop at idle stick. But for starters just leave the idle-up off.

Aztek1701 · #3 02-05-2007, 01:14 AM

Hi Logger,

Another possibility could be the throttle curve. Have you been adjusting that at all between test runs without the blades and test runs with. The reason I am wondering that is that most speed controllers wont arm unless the throttle is closed when the battery is plugged in which indicates that there is a throttle curve in there that isnt linear.

Hope this helps.... Azzy

logger1 · #4 02-05-2007, 03:58 AM

The throttle curve has always been left at the default of 0,50,75,100.

logger1 · #5 02-05-2007, 04:42 AM

Quote:

Originally Posted by chaos

Check to see if the idle-up switch is on. It should be off for learning. It should also be off when you first spin up the rotor. If you're going to fly inverted, after getting the rotor up to speed you would switch the idle-up on so that when the stick is in the low position you have negative pitch on the blades AND power to the motor. Then, after landing, you would flip the idle-up switch back to normal to bring the blades to a stop at idle stick. But for starters just leave the idle-up off.

The idle-up switch is off and the Idle up throttle curve was set the same as the Normal throttle curve so it shouldn't make a difference.

The way its acting seems to leave me to believe the throttle is being interepretted backward. That means that when I first powered it up the throttle was at full. I remember more tones than usually from the ESC when I powered it up which leaves me to believe it was in the Setup mode for the ESC. The motor spin up until I moved the throttle up. I did confirm that the throttle servo setting is not reversed.

chaos · #6 02-05-2007, 09:18 AM

I'm not experienced in electrics but my 2-cents would be to go through the ESC setup.

hawkman · #7 02-05-2007, 03:57 PM

The ESC set up is something you cant actually see.....I would reverse the function on your radio system.....thats what it sounds like to me anyway.

Rob

logger1 · #8 02-06-2007, 06:16 PM

Thanks for all the replies. I am a little confused in that it appears that the throttle on the radio has to be set "reverse". However I don't believe ever changed it and it was working in the "normal" previously. Is there anything I could have changed which could have reversed its function. When I look at the default on the other "MODL"
channel 3 is set to Norm.
I am using a Futaba T6EXHP.
Anyway with the throttle set to reverse it all appears normal.

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