The Tin Man - Conclusion

30 Oct 2021

The evolution of the Tin Man:

Credits: Line drawing on left from the original novel by L. Frank Baum and illustrated by W. W. Denslow

Center photograph of the Tin Man played by Jack Haley in the 1939 MGM movie

The image on the right of The Tin Man animatronic robot by me

Last-Minute Changes

I ended up making some last-minute changes due to last-minute problems this evening before taking The Tin Man over for the kids to see. The battery and battery management scheme had to be abandoned because my 18650 battery failed. I'm still trying to figure out exactly what happened. I ended up making a hole in the back of his head (with a hack saw - that makes me a hacker) and running USB cables through to power it from an external power bank.

The code that sequences the voice and servos was modified to play loops and a simple WiFi web page set up for control.

I'll post that code if anyone wants it but it is similar to what I've done before and described for Bender although I am trying to clean it up a bit and may post an improved version at some point.

The "voice changer" turned out to be barely understandable when recorded so instead Audacity was used. My methodology was to record the voice with Audacity and then lower the pitch and use effects like echo and reverb to make it sound like a robot. Unfortunately, I overdid the effects and is still hard to understand as can be seen in the video below. But in case anyone wants to do something similar, here is my recipe.

1) Select audio file with CTRL+A
2) Effect --> Change Pitch --> Frequency -15%
3) Effect --> Change Tempo --> Percent Change -10
4) Effect --> Echo --> Delay 
   time 0.015
   Decay factor 0.4
5) Reverb --> Reverb
   Room Size 75
   Pre-delay 10
   Reverberance 50
   Damping 50
   Tone Low 100
   Tone High 100
   Wet Gain -5
   Dry Gain -5
   Stereo Width 100
6) Amplify to within 2-3 dB of clipping
7) Test with play and export with file name

Reception

Well, it was kind of a bust. It seems the 8-year-old and the 10-year-old have become too sophisticated for my silliness And I was fiddling with it for too long and lost the 3-year-old. Fortunately, the 5-year-old has similar childish tastes in humor to me and I entertained her for a good 15-20 minutes.

The 30-second video below with a geeky joke was made especially for element14.

The first person to actually watch the video, get the joke, and comment below will get special recognition.

Final Thoughts

There are a lot of things I would change if I were to remake this project. The 3-D print is of poor quality, at least partially due to printing the shell with a thickness of 1.6mm instead of my normal 2.0mm. The eyes still aren't that great although the misalignment at the moment is due to me not recalibrating the center at the last minute in order to get the project out the door. The voice needs to be redone with less distortion. Some new consideration needs to be given to the power/battery solution.

It works and looks pretty good from a distance though. Thanks for reading. Thoughts, comments, and suggestions are always welcome.

Links

The Tin Man - Getting Started

The Tin Man - Getting Started | element14 | Frank Milburn The Tin Man - Mechanically and Electrically Complete

The Tin Man - Smooth Moves | element14 | Frank Milburn

The Tin Man - Velleman "Voice Changer Kit&... | element14 | Frank Milburn

The Tin Man - Mechanically and Electrically Com... | element14 | Frank Milburn