In an IC powered 2-metre F3A model, one of the significant factors governing the accuracy and reliability of the radio link is the condition of the feedback potentiometers in the servos.

From an earlier thread, it would appear that most owners of YS powered machines carry out preventative maintenance on potentiometers every 100 flights or so. Some change them more often.

The lower levels of vibration inherent in electric motors offer a possible solution to the problem. However for diehard members of the oily brigade, it begs the question about why, in the year 2005, we are still relying on a feedback mechanism containing moving parts.

Non-contacting rotary to digital converters using optical shaft encoders have been available for many years. The technology is widely used. A modelling example can be found in the Aeroperfect Digital Control Throw Meter -available from Tower Hobbies. The resolution of the encoder contained in this device is 0.05 degrees over a range of plus to minus 180 degrees. This should be more than enough for even the most accurate of pattern pilots. However because of the digital nature of the encoder, it would be a simple matter to increase the resolution even further should this ever be required.

Quite apart from a vast potential improvement in reliability, it would seem an obvious step to dispense with an old-fashioned analogue feedback device and move towards fully integrated digital technology.

I find it hard to believe that either price or miniaturisation would be major stumbling blocks. So does anyone know why the technology has not yet been adapted?

AA

PS:
I will also pose the question on Danny’s JR Forum