hobby_man
Posts: 230
Joined: 1/13/2004
From: circle pines,
MN, USA
Status: offline
|
quote:
ORIGINAL: whstlngdeath
Jeff,
Forget the instructions that Futaba gives you for the gyro. Turn on the AVCS feature and set the gain to 75%. When you are ready, connect the battery and don't touch or move the heli until the gyro initializes, about 5 seconds. Start to spool up the blades and see if the heli wants to start spinning around, or if it generally stays pointed in the direction it started at. If it stays, then you're ok, if it starts to spin uncontrollably, then reverse the direction switch on the gyro. Attempt a hover and see what the nose of the heli wants to do. If the tail starts to wag constantly, lower the gain a little at a time until the wag stops. If the nose starts to drift slowly in either direction, add a little more gain until this stops. The key to the Futaba GY240 gyro is that when you land to make a adustment, and you happen not to disconnect the battery, before you spool up again move the rudder stick left and right fast, several times and let the stick center. This will re-initialize the gyro and center the tail blades. If you don't do this, the gyro will continue to move the tail blades if you move the heli any, and then the blades will not be centered. This will make the heli jump and yaw the next time you spool up. I got in the habit of re-initializing the gyro before every spool up, and it really helps.
This method is for AVCS mode only. I never set up my gyro with the AVCS off, and it works great. Another thing you have to look at is how smooth the tail rotor is. There cannot be any binding, wobble or vibration at all. Look at the tail fins when you are spooled up and check for any vibration. The fins will show this as a high frequency vibration. Make sure the slider at the tail is super smooth. No binding. I lubed the steel tail shaft with lithium grease. Check the tail blades and see if they are turning true. Put the heli on a table, hold a straight object, (I used a CD case), flat on the table next to the blades, and spin the main rotor by hand. Look at the tail blades, and as each one passes by the CD case, (or whatever you use), make sure that each blade is the same distance from the straight edge. If one is closer to the object than the other, then there is a wobble in the tail rotor, or one of the tail blades is warped. Mine had both a warped tail blade, and the center hub of the tail rotor was not drilled straight. It sat on the shaft a little crooked. I ended up replacing the hub, grips and blades with a T-rex unit and carbon blades. Now all of my gyro problems are solved, and I can adjust the gain over 80% and tail locks solid. The tail is the most important part to tuning these small helis, and a little extra time and effort here will pay off with a easier to hover machine. Let me know how it goes...
Jesse
I had my mx400 flying great after months of learning curve. I smaked the heli on the ground and had to rebuild the head and the tail. I went to tesst fly it after the rebuild. The issuse I am having is WAG, I turned the gain to 10% and it still wags, nothing is binding, will moving the rudder stick real fast left and right help this issue? The heli is searching/wag while in flight, its like the gyro is bouncing back and forth, go left, no go right , back and forh
|
Printable Version
All Forums >> RC Helicopters >> Electric RC Helis >> Helimax >> RE: Mx-400 purchase 
RE: Mx-400 purchase - 
. You still need to take care and balance them well (mass and span both), but they track better than any other blade I've used, and the MX flies beautifully with them. My tips aren't a little off, not less than a mm off, they are exactly in plane and the edge of the rotor disc is razor sharp. 