Monday, April 07, 2008
Give me a big enough lever...
The real servos finally arrived! here is the Hi-Tech HS-805BB Mega Giant Scale Servo being tested. I simply attached one of the many great horns and plates that it comes with to my fish-line spool, using its own screw and voilà! 19.8 / 24.7 kg*cm (4.8V/6V) of torque! It is temporarily held in place with straps as you can see because as you can imagine the square holes of the Vex plates don't line up with anything but their own stuff (I promised I would stop bitching about it!)
For the rest of the controls I am using the HS-645MG UltraTorque Metal Gear Servos that have 7.7 / 9.6 kg*cm (4.8V/6V) of torque, very much on the safe side.
On the left of the picture you see Vex's red optical encoder which I planned to use to determine the position of the continuous rotation motors that lift the arms, but again, not even the extremely versatile Make controller could recognize the simple signal. I am sure it can be done but why waste time. I ordered a set of high-res 10 turn potentiometers that are not only more precise but can "hold" the last position even when the power is turned off.