Please Help

[Euwan]

I am on the verge of snapping.

So I am installing a GT5 on a trex 500 and basically I am trying to set up the tail limits (step 15 in the manual) no matter what I do the tail does not move, it is still binding at each end and if I leave the rudder at either end my ds520 servo gets hot really quickly.

I have tried lowering the travel on my DX8 but that just slows down the rate of the rudder. I am using a full sized rx ar8000, not sure if this makes a difference. My ds520 is set to 333 and 1520 which looks like 1500 on the GT5.

[rexxigpilot]

Euwan, first off do youself a favor and download the latest manual, version 2 = JC6276V2 GT5manual.pdf, from the Thunder Tiger website.
http://www.thundertiger.com/product/8085.html

It will explain a lot of what I'm about to write. The original Manual had numerous errors (although it has much better grammar instead of Chinglish.) The new manual instructs how to set the tail rotor limits in Step 17 instead of step 15 as in the older manual.

Now for your issue, never set limits on a tail servo using the endpoints/travel limits in your TX. These values will adjust the pirouette rate only just like on a tail only gyro system. Set travel/endpoints back to 100 in your DX8. Next remove the link from your tail bellcrank when setting limits. This way your rudder servo doesn't bind and overheat/burn out! Just loosely hold the link on top of the ball with your finger while setting the limits. Move your rudder stick to full right or left and adjust the GT5 (A) or (B) value until the link is directly over the ball center while the slider is all the way to one end or the other. Move the rudder stick and slider to the opposite direction and adjust the other GT5 (A) or (B) limit value the same way. You will have to back off a bit more on the limits after you get the correct value for full tail blade slider travel without binding since once you snap the link back on it will be too long. You know, the shortest distance between two points is a straight line thing.

Note that there is an error in the screen Values for setting the Rudder (A) and (B) direction limits. It shows 280 on top, 100 in the middle and 100 again on the bottom. The middle value should read and is actually 190. If you have changed the limits in the GT5 to 100 on each side (A) and (B) and still get binding, your servo arm is too long, shorten it. If there seems to be no change in the link position when you adjust the limit value in the GT5, you are using the wrong direction (A) or (B), change to correct direction screen.

My values ended up being 205 for direction (A) and 140 for (B). So the ball position on my servo arm is just right on my T-Rex 700N at 17mm. I could change this to a 14mm distance to maximize my servo resolution (I would have larger limit values like 210 on each side), but my tail holds like a rock now and I would lose speed to gain resolution.

Hope this helps.

[Euwan]

Thank you for the help will have a check later today