ARK X-400 build

[Robman]

Any tips or mods I need to do while building this heli or any advice on first flight..I've flow my e-flite blade for a week now and want to move up a little..
Thanks Rob

[WayneBrown]

Use blue locktite on metal to metal, Medium CA on screws to plastic and plastic to plastic.
Get Steve at Hobbytown to get a JR ball link sizing tool, and use it on ALL links.
Make certain to center all servos and trims BEFORE installing servos, and 'square' all arms or wheels, making sure that the point of connection between the ball is 90 degrees to the servo housing, there are splines on the servo arms and shafts to help line 'em up.
I'd reccomend a Futaba GY 240, or GY 401 gyro for this also, a 401 is what I have on the T Rex.
Ask questions, and if you are really stuck, take a picture and post it for us to look at, you'll likely get a lot of valid answers very quickly.
Glad to see you made it to the Freak! You won't be disapointed here!

[blakka_1]

This site covers everything. :)

www.x400tuning.com

[Robman]

I've got a problem with the gyro..( futaba 401 )It want hold the heli straight...what do I need to do..I'm on my third set of blades and second tail boom... Sure wish I had someone around here who knows how to trim one out!!

Thanks Rob

[Hotshot Charlie]

Hey Rob,

If you get a chance and have time, drive over to Tupelo and we will see if we can help..... between Alan, Dan and I, we can get it figured out.

[WayneBrown]

crank the gain (ch 5) up to around 70% in AVCS mode (led solid on).

[Robman]

Thanks Rob an wayne. I know I sound dumb but how and where is the gain on a 7C futaba? Avcs means heading hold right? :dontknow
Thanks Rob

[Hotshot Charlie]

Dont' know about Futaba, but AVCS is the Heading Hold "Locked In". Blinking is in rate mode.

[big-al]

if I rember right we set your gain up on the gyro screen. that is where you set what gain you want on the tail.

if its drifting, its moving around the same direction and speed each time. that is countered using rudder sub trim to stop it. this is usually noticable in all flight regeimes.

it it is not holding or wagging bad, that is set by adjusting your gain values up and down. wagging means too high a gain, not holding means gain not high enough. this is noticiable with pitch/throttle changes.

I also don't remember if we got yours set up mechanically or not. maybe dan or rob will remember. I want to say we did. we just set up too many helis that weekend though.

[WayneBrown]

Gyro should be switch "E" if I remember correctly, this seems to be the default switch.
It should be active away or down from the switch. In AVCS the LED on the gyro will remain constantly on, where rate or normal mode will be off. Moving the stick or trim will cause the light to blink.

[Robman]

Under gyro settings , up is at 70% and Dn is at 70% and it's set up on switch B..
When the heli first leaves the ground it turns to the right about 90 degrees then if I go up or down it will turn again about 90 degrees to the right..

Rob

[WayneBrown]

which position is the light constantly on?
make sure the switch is in the position for ou start the gythe light to be solid each time gyro.

It almost sounds like a bind in the linkage somewhere... loosen the linkage rod from the servo, and make sure it is smooth. I'm guessing your servo is fighting to overcome the bind, and then overcompensating. Let us know if you find anything.

[Robman]

Ok I get it in a hover and the nose want to drift to the left so I trim to make up for it but with the stick all the way to the right the nose will not trun right and letting off of the stick to back to center doesn't make any difference and the nose still wants to drift to the left..Why is the gyro not holding it? The tail rotor uses all it's travel in and out... The light on the 401 is steady on so it in head hold mode? What do I need to try now? :arggg:
Thanks Rob

[DavidH]

First,
Center the trim on the rudder channel.
Then hover the heli with the gyro in normal mode.
Now mechanically adjust the tail linkage till the heli will hover straight pretty much without any tail inputs.
Now land the tail and flip the switch 3 times real fast between AVCS and Normal mode. End up with the switch in AVCS mode.
Now hover the heli and the gyro should hold the tail if you have the gain set high enough. The gyro will hold great with 40% gain.
Make sure there is no revo mixing activated. Make sure the subtrims on the rudder channel are set to 0.

David

[WayneBrown]

Same result, different method.
All is done on the bench, You may power the reciever with a 4.8V nicd for the following setup.
Fold main blades, or remove Your choice.
Lay Heli on side, bottom facing you.
Loosen tailrotor servo mounts.
Look for linkage bellcrank on tailrotor.
Adjust by moving servo fore/aft until bellcrank lines up with boss on tailrotor case beyond.
Tighten servo mounts.
Now plug back in your speed control, and power up heli in AVCS mode.
Switch to normal mode, and attempt hover, if tail swings right or left, land and adjust servo mounts as above until a 'reasonable' hover can be established.
Once you've gotten it close enough using this method mechanically, AVCS mode should hold without issues.
Once you have it to hold, measure the distance from servo center to tailrotor gearbox and note it in your manual. It will come in handy after a crash by giving you a shortcut.
If you get stuck, call me and I'll walk you through it step by step.

[Robman]

Thanks I'll try it tonight....

[Robman]

Had a motor melt down! 260 degrees now it doesent want to run..I got a mega 16/15/6 will that work?
thanks Rob

[WayneBrown]

I suspect it would, but I don't know for sure.

[Robman]

well a 16/15 /5 want do it.. Wayne , What are you running on your trex? What motor should I get? I want be doing any 3D for quite some time..

Thanks Rob

[WayneBrown]

I'm running the Align 420 LF, stock 3200KV motor.
It 3D's okay enough for me to learn new stuff, but not as hard as some.
I tried a 2025-5300 Himax, and it was waaaaaaaaaaaaaay too much, it actually split links off the rods. I wouldn't reccomend this one.
Steve might be able to get one if He's carrying T-Rexes now.

[Robman]

Ok before I lost the motor I trimmed it so it hovered pretty straight with head hold off and that helped the gyro hold it straight but i still can't make the nose turn right.. When I apply throttle the nose goes left and only when backing off throttle wil the nose turn right with the stick all the way right.. :dontknow :bomb:

[Robman]

Would this be a good buy?

http://www.rcgroups.com/forums/showthread.php?t=432505

Thanks

[Robman]

Ok New motor installed and it is flying much better.. The tail waggles now.. What do I need to do to stop it?

Thanks Rob

[WayneBrown]

make sure the pitch slider moves freely on the shaft, and that all linkage is free on the tail.
Oil it liberally, and try it again. It will get better, or you will find the cause. It doesn't take much to make them wag, so get everything as smooth as you can.

[Robman]

Son of a!!!!! :arggg: my new algin motor smoked on the 5th battery..Just hovering around... The temp was only 118 deg....Am i doing something wrong? I'm just flying it with the throttle should I be runing it at one head speed and using the pitch to go up and down.. Would this help?

Going crazy
Rob