jlmrph

My Feedback: (7)

HI
I am wondering if this suituation is common with hitec or a radio problem. I am using a hitec micro servo 81 for my throttle in a profile plane. It works great except I can not make the throttle cut or trim work on the low side of the stick whether or not I reverse the servo in the radio setting. The radio is an airtronics rd8000. On the high end of throttle the throotle cut and trim work. I have adjusted the epa and centering but it just doesn't seem to get the t-cut or trim inputs on the low side. has anyone had this problem. thanks
jlmrph

mglavin

My Feedback: (31)

A few questions:

Does the throttle cut function with other servos?

Is the throttle cut function activated?

Have you verified the servo works otherwise?

Have you tried it without the servo arm in place?

bill ulmer

My Feedback: (1)

mglavin jlmrph's computer is down right now. I am a flying buddy of his helping him figure this hitec servo problem out. Yes the throttle cut function is turned on , set to maximum throttle cut, and airtronics servos work correctly. The servo works smoothly both directions and moves the carb, arm fine. Going down the function list in the radio program we have tried TRIM + and _ numbers, reversing does not help(from low throttle, idle trim and throttle cut don't start working until the throttle stick starts moving up and then the farther up the stick is moved the more throttle cut and trim movement you have . CNT + or _ doesn't help. EPA + or_ doesn't help. T-CUT set to a full -100%(there is no +100% choice). We have tried turning the servo arm 180 degrees on the servo shaft. No matter how the radio programing is set the throttle cut or throttle trim won't respond until the throttle stick is in the full normal up-full throttle position. Is the hitec servo somehow built or programmed to respond backwards when using an airtronics radio?

mglavin

My Feedback: (31)

Bill

It unlikely the servo is causing the problem based on your comments of the function working at full throttle. I can't help but believe your problem is associated to the TX's programming. Most TX's don't allow this function to operate unless the throttle stick is close to idle position. It maybe possible the servo needs to be reversed at the TX... Hitec's servos may operate in the opposite direction of Airtronics out of the box. But that does not explain why it works at full throttle in my mind. Again sounds like a programming parameter astray.

I would contact Airtronics Service Department and see if they can offer a solution.

Hitec servos operate within the industry standard 900-2100us pulse width. It matters not what drives it as long as it’s within this range. As I noted above the rotation maybe be backwards from other OEM equipment.

Please keep us posted on your results.

jlmrph

My Feedback: (7)

hi mike
You are correct. The problem was in the radio. We were able to make to throttle cut work when we used another rd6000 airtronic radio and rematched the receiver with a crystal to match the new radio. We set up the radios identical and had no problem with the
new radio. We will be sending in the radio for repair. thanks for your help jlmrph

jlmrph

My Feedback: (7)

addition to earlier post
It turns out that if the spoileron function is active on the rd6000 , the tcut and trim will not work on the lower side of the throttle stick . only works on the top side. Hope this helps if someone else has this problem. Just turn this function off and all works well .