This is a very cheap tools that will allow you trim your sailplanes more easily. It gives the angle your rudders moves. It will take you no more than 20 minutes to build it, follow me !

The principle is really simple : it is a single dial to be be put on the rudders, thanks to a clothes pin. Then a small needle displays the angle when moving the rudders, powered only by gravity ! That's all !!!

What you need to built that tools :

• A piece of plywood 20/10 mm :
  With a protactor, mark the angle range you need, by step of 2° or less according to the accuracy you need in your measurement. I choose +/- 30° for the "high definition" scale, and +/- 60° for the less precise scale.
• A small nail :
  Nail it at the top of the angle sector, so that you can hook the needle. You need a slice, in order to separate the needle to the plywood dial.
• The needle made of steel wire 10/10 mm :
  In my case, the link to the nail is not really accurate : a single loop. You can make better...
• A piece of lead :
  It prevents from static fristion, that spoils a bit the measurement.
• A clothes pin.
• A 2 mm bolt :
  It is in france exactly the size of the hole provided by the clothes pin spring.

   You can try it !
Here is the way to use it :

1. Grip the "débattomètre" on the rudder, keeping in mind to avoid as much as possible friction on the plywood.
2. Adjust the zero (the dial must rotate quite easily on the bolt).
3. Then move the rudder and read the measurement.

   Just keep in mind : the accuracy of the measurement is highly linked to the care involved in the building, especialy the nail-needle link. Mine gives a +/- 2° precision, due to static friction : it is not quite extraordinary, you might make better.
   Something else : mind the weight of the tools, a too heavy one could alter the measurement

   Now you have a new tool, that will help you, I hope.

Contact me !