ksechler

I am pretty new to the whole electric scene. I have a TREX 450 SE with the Align 430 motor, 35a esc, and TP 2200mah battery. I don't remember the battery rating but it is greater than 20C. So I'm wondering, how hot is normal for a battery, speed controller and motor to get. Right now with the mild temperatures (50-60F) and a "mild" flight profile (hover, figure 8's, etc) the battery is warm to the touch. The motor is hot to touch as is the speed control but not hot enough to burn. When my skill level increases, I anticipate using more throttle and creating more heat. So I thought it might be good to know what's normal.

Second, this is a 401 gyro/tail setup question. First, my TREX pivots with the tail pitch slider in the center. In order to get hands free flight the slider must be set noticably to the right of center. This, then limits travel and gives me less than stellar rotation. Is there some adjustment I am missing? Second, I have noticed that the first 1/2 to 3/4 of the (servo/pitch) travel responds quickly but then it creeps through the remainder with the tx stick hard right or left. This only happens with the gyro connected. Why? Last, in order to get reasonable response from my tail, I had to put a lot of exponential in. Is it normal to use expo. on the tail? I am using a 401 with a 9650 digital servo. The radia is a Futaba 7 CAP.

blacksheep1998

Check out the finless bob videos on helifreak on the 401 setup. You set the servo, and linkage so that the tail is in the middle of it's travel. then use the limit pot on the 401 to set the max travel each way. When the heli spins up the gyro will take over and put the tail in the right place to hold direction. Provided you have your radio setup properly for HH mode.

Pete

ksechler

I watched the finless video, but what you said isn't completely true. The 401 takes its neutral from the TX when it initializes in HH mode. So if there's a trim setting or whatever it will pick it up, but there is a limit to how much offset it will take. Then it sends an alarm message by blinking LED.

Anyway the offset isn't the problem. I can fly the heli and the 401 does account for the offset in HH. The problem is I don't get much throw because of the offset and my tail authority sucks as a result.

BarracudaHockey

My Feedback: (11)

Setting up a 401 on a Trex is a compromise. If you want it to work well, do away with the idea of rate mode and doing a rate mode setup.

Run the shortest servo arm you can, I had to drill a hole in the existing arm for the 9650, and center the tail pitch slider with the arm at 90 degrees to the linkage. Run as high a limit as you can get on the limit pot without binding the servo.

Init and fly in heading hold only.

Adjust your piro rate by setting the end points on the rudder channel, expo is no problem, some people run it some dont, negative expo on Futaba softens center and expo has no effect on gyro performence.

Make sure you have no sub trim and zero rudder trim in all flight modes.

ksechler

Cuda:
You hit on something that I want to go into a little more. I have a homemade arm on the 9650 which is as short as I can make it and still have the hardware clear, which places it right next to the spline. I had to limit the throw at the TX to 40% to keep from binding. I tried 100% at the TX but the pot on the 401 didn't allow me to sufficiently limit travel. Maybe I set it up wrong. What is the functionality on the pot? Is it 0-100% of throw? If so, it should be impossible not to find a suiteable setting, right? Do you set the pot in "normal" mode or AVS?

blacksheep1998

Finless bob is using the same radio and servo as you, he has it exactly the way you need to set to get HH and normal mode setup properly. The GYRO takes it's neutral from the way it is pointing when it initalizes, if you move the heli the gyro in HH tries to correct by moving the tail in/out.

You want to center the servo, attach the arm, and move the servo until the tail is centered on the shaft. Then plug in a batt, have the gyro in normal mode then set your travel to 100% each way for the rudder channel. Change the pot to where you do not get binding in each direction. no light equals standard, solid means HH, and blinking the gyro did not initalize properly.

Pete

Tolla

I had the same problem with the tail slider. (If I could get those Finless videos to download I'd watch them)
Try as I may, my slider also had to be 2/3 to the left to stop rotation, limiting rudder movement in that direction. Finally I just gently heated the tail blades over a candle and twisted some pitch into them.
End of problem. My slider is now in the center and I have plenty movement in both direction.
Very little pitch needs to be added.
Eflite G90 gyro with Futaba S3154 servo.

cflight

As Align has made many improvements, how has the tail design gone unadressed?
Almost as if the crome peice atatched to the slider got switched around and I can hear someone saying, after production started ,(You think they'll notice?).

tippy

Got enough Main rotor RPM. Less than nominal main rotor RPM will give sluggish performance at the tail also. If you're RPM was below normal then the authority the tail rotor pitch gave to control the heli below normal. You would have to compensate with more tail rotor pitch ( " ... In order to get hands free flight the slider must be set noticably to the right of center ... ")

So make sure you have enough main rotor RPM to give the Tail Rotor sufficient authority.

BarracudaHockey

My Feedback: (11)

Limiting the throw by using the transmitter atvs doesnt really change much but the piro rate. If you are using a short (5mm or so) linkage, and set up the tail slider in the center you should be able to get about 80 or so on the limit pot which limits over all servo travel, not the ATVs. Also thats set up in RATE mode (light off). You just have to make sure you are initializing the gyro in heading hold mode, and not moving either the sticks or jiggling the helicopter around until the light comes on solid (around 3 seconds) which is a pain with the Trex due to hooking up the deans conectors.

Tolla

Cflight,
so there are other people who have the same problem as well?

Tippy
At almost 2700 RPM that should have been plenty for the tail.

Anyway, bending a litle pitch into each tail blade has cured my problem. TREX ROCKS!

ksechler

All:
Thanks for the replies. It turns out that I had some binding in the linkage. I got everything freed up, checked the head speed (2100-2200 rpm), centered and readjusted the endpoints. Everything is perfect now. The tail was actually a little too quick -perfect!