I’ve managed to fix my tail wag issue on my T-Rex 250. Thought I’d share it with those of you who are looking for a solution.
I basically did the following:
1) I made my own “chinese weights” for the tail by using the nut ends of EZ Connectors and putting them through longer screws used to secure the tail blades. With the Nuts as added weight, it perfectly balanced the tennis raquet effect of the unweighted tail grips. After making adjustment, I was able to move the tail pitch slider (with or without the tail blades) easily without much force and when I let go of the pushrod, it would stay in place instead of move back to the center. The basically cures the high-torque needed to move the original tail slider due to design flaws.
2) I substituted the Align DS420 with a DS520 servo. I’m not sure if the 520 is needed after my fix above since I made the changes at the same time but the 520 definitely packs a bigger punch in terms of torque delivered to the tail slider.
As a result of the above changes, My GYRO Sensitivity which was previously at 60% is now up to 70%. I am probably also able to move it up to 75% without getting much wag but since I have changed my pinion from 15T to 16T now, I had to dial it back a little to prevent tail wag.
The Heli now feels locked in. I have yet to test full collective climb outs but I have a feeling the tail will hold this time round. Here’s to having more enjoyable flights rather than an expensive paper weight 🙂
I’ve also ordered a set of new tail grips from Align which comes with the counter weights. I’ll put them on to see if they perform as well as my mod but I doubt it since I’ve seen a video on YouTube which shows that the weights on the new tail grips are still not heavy enough to counter the tennis raquet effect. We shall see…
UPDATE – 4 July 2009 : I’ve installed the new tail grips from Align (which comes with the larger screw heads – thus new allen screwdriver is needed), and true enough, the weights on them does not make a big enough difference. As such I decided to put on my mod onto the tail which seems to even improve it more. Pls refer to the pictures below to see how I’ve done it.
Basically the new tail from Align and the weighted nuts did the job of curing the tail issue. When spooled up, I can move the tail freely with hand and if I leave it at any spot, it does not move or spring back to any position. Having said that, I’ve left the DS520 on the tail because that seems to deliver more power than the DS420 which in my opinion is a little on the weak side. Good Luck Guys