I decided to take a break from the double star to attempt the electronics portion of the BFKK kit. Specifically the task involves modifiying a stock Futaba S3004 servo to provide 360 degree rotation. The regular servos have three things that prevent endless rotation. There are plastic tabs on the inner lid of the servo and a plastic block on the main drive gear, and finally the trim pot used will not support full rotation.
The instructions included with BFKK made this task a breeze. I had never soldered before so I was a little nervous. I used the desoldering braid as suggested in the manual, and once I got the servo electonics to sit still and had the braid positioned in the pliers properly everything went fine. Adding the new Cermet Trim Pot was much easier than I thought, and my soldering doesn’t look too bad . I plugged everything in and after a little fine tuning with the trim screw it stopped spinning and worked great.
I had one small problem after I performed a test assembly. The block on the main gear drive really has to be filed down to ensure that one of the secondary gears does not rub against it. My first attempt caused the servo to pause slightly in it’s rotation as it passed the old block location. I filed the site of the old block even more and now have smooth rotation.