Having trimming problems? this may help - RC Groups
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Feb 22, 2013, 10:05 PM
RC Heli Junky
countrybo89's Avatar

Having trimming problems? this may help

This is what i do to check my flybar's level. its not expensive at all to make. you might spend a dollar at a hardware store for this.
(Make sure the tube will click on to your flybar so buy a couple different sizes and just take the level bar from and old leveling tool)

flybarlevel (1 min 16 sec)

When you attach this item spin the flybar in 4 points. front, back, left, right and adjust your links (not your trim) to get it level on all 4 points.
(Sometimes this can be your only problem but if its not the simple fix read more)

on my 450 3D heli there are 4 links to the flybar. i dont know about yours, look closely and see how many connect to your flybar. i have never seen your heli's rotor head so idk some are different, anyways about how to adjust the links. if you pull off a link arm and look at the tips carefully you will notice the tips are threaded and the links twist. As you twist them it will make the arm longer and short not by much but enough combined with both ends. (just like a nut on a screw twist left nut goes up, twist right nut goes down same thing) JUST REMEMBER WHEN ADJUSTING LEVELS ON A HELI ALWAYS WORK FROM THE BOTTOM UP AND UN PLUG YOUR MOTOR. (3 small wires running from the ESC to the motor unplug 2 of the colored wires, black is not needed to unplug its just a ground wire) you should adjust every thing with heli plugged in and powered on, TX powered on and binded to heli, with all Trims at 0 and heli is in idle up mode. (MAKE SURE YOUR MOTOR IS UNPLUGGED I CANT EXPRESS THIS ENOUGH IF NOT IT CAN GET UGLY FAST)

first step make sure your servos are at 90 degrees to the servo box and to the link. (this does not mean just move the servo arm) Take the servo arm off and under the arm there's a little pin tip size pin, with the trims at 0 twist the pin very very slowly left or right untill its at center. (you'll know its at center its common sense) that little pin is called the POT.then put the arm back on at 90 degrees to the box and to the link adjust link if needed, like i described before do this to all the servos on heli.

now take off your rotor head and level your swashplate using your swashplate leveling tool.(REMEMBER NO GAPS BETWEEN TOOL AND SWASH AT ALL POINT 0%, 50%, 100% ON THROTTLE STICK) After that's level at all points in idle up mode, put your rotor head back on reattach every thing adjusting links if needed.

Now move (UP) to your flybar, using the method i gave you to level your flybar and adjust your links up and down, get it level 360 degrees all the way around.( don't touch the flybar when rotating it around. just touching the flybar can cause it to move and go off balance giving you an inaccurate reading. get it level first with your tool then just rotate the main blades clockwise without twisting them and adjust as you go) it will never be absolutely perfect but that's what trims are for after every thing is done. now that your flybar is decently level now use your pitch gauge to make sure your flybar paddles are at 0 pitch. (REMEMBER THE FLYBAR IS NOT FOR LIFT ITS FOR BALANCE SO NO PITCH IS NEEDED) im assuming you know how to use a pitch gauge if not take a look at this video.

Blade 400 3d Pitch Gauge 101 (6 min 38 sec)

The method he use to level his flybar can be used too but trust me the method i showed you works better. it gets it closer to level than just your eye can provide. now adjusting the flybar paddles are simple common sense. just look closely at it you'll find your answer young grasshopper lol .

Now that thats done and every thing is level at 0 trims now do your main blade pitches using your pitch gauge. its better to do your main blades pitch in idle up mode so you can adjust all your pitches -10 degrees negative or 0% , 10 degrees positive or 100% and 0 degrees at center or 50%. the last video can show you that (BLADE TRACKING IS ALMOST THE SAME AS ADJUSTING YOUR PITCH BECAUSE IF YOUR PITCH IS OFF ON ONE OF YOUR BLADES THAT BLADE WILL TRACK HIGHER OR LOWER)the only things that can cause a blade to go off track is, loose blade clamps,warped or bend blades, broken or not correctly adjusted links, (basically every thing being offset) and of course different pitch degree on each blade (REMEMBER YOU HAVE TO ADJUST THE PITCH ON BOTH BLADES, NOT JUST ONE AND YOUR DONE OR YOUR BLADE TRACKING WILL BE OFF AND YOUR PITCH WONT BE CORRECT, LEADING TO DISASTER!!!)

now after that make sure your tail rotor is set. Make sure the gyro gain is good and tail servo is at 90 degrees. with the gyro gain you want to be flying at least over 3ft ill explain more as you read. turn your gyro gain up until the tail starts to shake or (WAG) then reduce slowly till it stops and the heli's tail holds in HH mode or (HEAD HOLD mode) if you have a tx with a knob for your gyro gain, when you turn it up past 50% it turns HH mode on under 50% and your in RM. (RATE MODE) GIVE OR TAKE A LITTLE SOME TOGGLE ON AT 50% ,40%, 60%. YOU WILL KNOW IF ITS ON YOU'LL NOTICE THE DIFFERENCE IN THE 2 MODES. in rate mode use rudder mix knob to center heli's tail (kinda like a trim but your not using your trim bars) YOU CAN USE TRIM IN RM FOR SMALLER ADJUSTMENTS. in rate mode what ever direction you go the tail will follow along some people swear by this mode for scale flying (realistic flying like real choppers) ITS UP TO YOU WHAT YOU LIKE MORE HH OR RM. in HH mode the gyro forces the tail to hold its direction under even extreme circumstances by countering its rotation automatically until you tell it to move using your rudder stick (THIS IS WHY I SAY NO TRIM IS ALLOWED IN HH MODE)

idk what kinda TX you have so i don't know if its digital or a knob if its a knob then you should have 2 knobs 1 for rudder mix turn this all the way down or off and 1 for gyro gain. if digital look at you TX manual for where to find rudder mix/gyro gain (REMEMBER YOU NEVER USE RUDDER TRIM IN HH MODE IT SHOULD BE AT 0 OR IT TELLS THE GYRO THAT THE HELI NEEDS TO TURN THAT DIRECTION WHEN YOU USE TRIM) THINK OF IT LIKE THIS IN HH MODE ITS NOT A TRIM ANYMORE ITS JUST LIKE YOUR RUDDER STICK JUST SMALLER AND LESS PITCH TO YOU TAIL AND YES YOU CAN USE IT TO MAKE SMALL TURNS BUT I DONT RECOMMEND IT TILL YOU GET GOOD) if the heli starts spinning like crazy with the gyro gain up and all the previous steps are right, chances are its reversed or its a bad gyro. (there not expensive to buy better ones)

now after all these steps are completed get your heli off the ground over 3ft because of ground interference. when a heli first lifts off the ground it will try to go left or right or a random direction because of wind hitting the ground, bouncing back into the blades. (hints the name ground interference) That's where good piloting comes in to factor on lift off. At a hover at 4ft start trimming if you still cant trim it then you did something wrong in the steps or something is probably broken or not working properly. (REMEMBER MEASURE TWICE CUT ONCE)

Good luck and happy flying
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Feb 24, 2013, 03:57 PM
RC Heli Junky
countrybo89's Avatar
does any one have any comments or add ons that i may have forgotten or fail to speak of
Feb 24, 2013, 04:03 PM
RC Heli Junky
countrybo89's Avatar
post your videos of your trimmed heli's after this advice lets see how those heli's fly now

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