Building an Inverted Pendulum System The Ups and Downs of Defying Gravity…

Realized that the original bad encoder (#1) probably has a working LED, while the encoder I broke (#2) has everything but a working LED.  Thought maybe I could move all the working components from #2 to the case of #1.  Started by removing the retaining ring on #1, then pounding the shaft out of the bearings.  Managed to remove the shaft, then the two ball bearings supporting the shaft.  At this point, realized there was no way we could get the shaft with the glass encoder disk out of #2 and into #1 without destroying the glass, which is very thin.

Ordered several different infrared LEDs from Digikey for about $5.  Hoping one of them will work with the broken encoder.  Not sure if the light needs to go through the lens or if the LED can be close to the sensor.  This is a last ditch effort, but I really can’t lose for just $5.

Placed a bid on ebay for a DRC encoder that looks like it will replace the broken encoder.  Same size shaft and has the differential signals I need.

Encoders not quite as bad as I originally thought.  I decided if I could remove the circuit board, I could fix the solder beads on the back of the board and reassemble everything safely.  Started by scraping off all the glue around the edge of the circuit boards.  After a little trial and error with the original non-functioning encoder (and shattering the glass disk on it), I figured out how to pop out the circuit board.  Cleaned up the solder on the back of the boards and reassembled everything.  One encoder works fine now – it has good signals and turns smoothly.  The other encoder still doesn’t work.  It turns out that when I popped out the circuit board, I accidentally yanked one of the wires off the LED which is at the bottom of a deep, dark hole with a lens above it.  No way to possibly reattach that wire.  At least now I only need to buy one replacement encoder.