Procedure for replacing the tail servo on the B400 with Spektrum DSP75?

[BKF]

Ok, so I figured I'd go ahead and replace the tail servo with the Spektrum DSP75. I got the old one out, put the new one in, fired up the heli and let it center the servo. Then I put the horn back on about 90 degrees up, which seemed to have the tail rotors flat, with no "lift" to either side.

Now, I know there's some stuff I have to do in the radio, but what? I reversed the rudder input, so left is left and right is right. I flipped the switch on the gyro to DS mode.

Now, I'm stumped... Do I flip any other switches on the gyro? Do I reverse the "Gyro" setting in the radio as well? I thought so, and fired it up and rotated the tail to see if it countered with movement of the tail rotors. With the default gyro setting in the radio, it moved the tail rotors, but I'm pretty sure they're moving in reverse of what they should be doing (didn't fire up to verify... it's too dark to take it outside right now and not enough room inside). If I reverse the gyro in the radio, they don't seem to move at all to counter rotation if I swing the tail end around on a table back and forth through half a circle.

Did I do it right, or am I missing something? I'm thinking I need to flip the other switch on the gyro? And what about gain setting in the radio? What's the proper number for HH mode?

[carlo_the_wonder_frog]

When you give it full right rudder the pitch link will move closer to the boom causing the blades to push air and therefore making the heli go right. If it spins when it gets light on its skids, first switch the reverse switch on the gyro and retry, if that didnt fix it next try reversing the rudder channel, if still spinning reverse the gyro again. You will know your in HH mode when you set it on the bench and give if full right/left rudder and the blade pitch does not return to center when the stick does.

[BKF]

Thanks. I had switched the gyro switch to reverse after nothing else worked, and pitched the heli around on the bench after arming the gyro. Seems to put the rotors into proper position now.

Also, it does exactly as you explain... it doesn't return to center during manual rudder operation.

It's been raining and/or windy here for over a week now, so I haven't gotten out to fly. I finally have the swash level, and the new tail servo all set and I can't try the darn thing! Argh!


When you give it full right rudder the pitch link will move closer to the boom causing the blades to push air and therefore making the heli go right. If it spins when it gets light on its skids, first switch the reverse switch on the gyro and retry, if that didnt fix it next try reversing the rudder channel, if still spinning reverse the gyro again. You will know your in HH mode when you set it on the bench and give if full right/left rudder and the blade pitch does not return to center when the stick does.

[carlo_the_wonder_frog]

I know exactly how you feel, its so dang cold here only a very brave and coldblooded person dares to fly outside. If its windy here the windchill can hit 50 below zero and the LiPo's hate the cold. Suffice to say i haven't flown any of my outdoor helis in 2 months now. Realflight sim gets alot of use though and I still fly some of my smaller airplanes around the house and street. Of course my CX2 gets used a bit inside, sure hope spring comes early so I can be out flying by the end of april ( It still snows here in april).

[BKF]

I've spending a load of time in RF G4... But I'm seriously considering buying a CX2 to fly inside the house now. I think my wife might hurt me, though.