NOTE! There are a couple of different designs of these servos, even from the same vendor.
- The written notes below are for a through-hole style board
- The video covers the non-through-hole syle
- One kind of Potentiometer has rotation stoppers which must be broken off.
- One kind of Potentiometer rotates freely and doesn't need to be modified.
- If you don't need to modify the pot, you don't have to remove the stack of gears.
Continuous rotation servers are popular for cheap robotics projects because a pair of them give you a complete drive train (motor, controller, and gears). A pair of 9 gram servos (such as the popular HXT900 from hobbyking) should be less than $7 or so.
The motor wires are minimally soldered, and may come loose from the PC board as you're working through the steps below. If that happens, just resolder onto the proper position.
NOTE: you may not have through holes on the board. In that case, you will just solder the resistors directly to the board as per the video.
I saw a photo of some 9 gram servos where the three wire through-holes were right next to each other, and just the right size for bridging some 0804 sized SMD resistors. If this applies to your servos, it will certainly make it easier to put the case back together.
It will pop right out of the hole.
NOTE: don't do this if the pot already spins freely already.
However you do it, just make sure you can spin the pot freely. Keep busting off pieces until you get it right.