Update after the Fair. The Fair was 9 days at least 10 hours a day. The Captain Underpants toilet ran for the entire fair. Some parts worked a lot better than other parts. The toilet bowl lid worked fantastic, it was rock solid. The Eyes worked very well, had a problem with the hot glue I mounted them with. The toilet was outside and it got very hot, the hot glue did not hold the entire time. I had to reattach the eyes at least twice. Their where two main problems, the worst was the tank lid mechanism, it basically did not work. After the first day I turned off the Tank Lid and had it in the open position so you could see the eyes.
I also had problems with the speakers. The speakers ran off 4 AAA batteries and they would only last for use under 2 hours. Around the third day I converted the speakers to run off the 5v system. It was very hard to work on anything at the fair, the heat and trying to solder anything. While this solution worked it still had issues, lot of distortion ( was meant to run off 6v not 5v) and the regulator would over heat.
I have totally redesigned the tank lid mechanism to use a CAM. I will upload all the stl files, I 3D printed all the parts. There where several versions as I tweaked the design. I'm including a video where you can see the design and how smooth the movement is now. I'm very happy with this design it will be reliable.
I'm going to upgrade the Eyes to RGB Leds. Also I'm going to drive the sound arduino off a new switch that I added instead of controlling it from the master arduino. The motors produce a lot of noise, and I have intermittent problems with the sound not being kicked off.
I'm going to put it out for halloween with all the updates and enhancements. I will upload video from that. Looking forward to being able to have the Eyes change from Green to Red then Purple.