Excali-weenie, Slayer of Burnt Hot Dogs, Bane of All Over-Roasted Marshmallows!


Step 2: The Non-Theoretical Prototype Plan

Picture of The Non-Theoretical Prototype Plan
Now, I realize it's easy to criticize any given product or piece of technology.  But as I have often exprienced in my design work, many flaws of designs have trade-offs: mass manufacturing difficulties can arise, certain features that provide a great solution in one area make for a horrible experience in another. That being said the following prototype was the best I could execute on my theoretical "perfect" roaster given my resources of time, money, and proof of concept goals.  

The Plan of Action

Problems & Solutions:
  • Too Short - Increase the length of the roaster.
  • Too Flimsy - Use thicker gauge steel wire for roasting stick to prevent flex.
  • Difficult to Turn - Motorize the roasting stick with a small DC motor and switch. Gear the motor down with an extremely high gear ratio of around 1:200 - 1:500 to give it enough torque to rotate a average hot dog. House the motor, batteries, and switch in roasting stick handle. 
  • Not Awesome Enough - Make the roaster in the loose form of a sword.  What kid (kid adults included) wouldn't love the fun of pretending they are some ancient night skewering evil hot dog monsters and ghost marshmallows. I know I do.
Concepts Needed Proving:
  • Can a small DC motor be geared down to a reasonable size and last long enough on a few AA batteries to rotate a an average 2oz (+/- 55g)  hot dog for a total of 30 minutes to an hour of roasting time.

Once I had those goals in mind, I set off on the nitty gritty of the prototype build.

Research Phase:  

The Motor & Transmission: I researched motors and found a commercially available dc motor for purchase from a manufacturer with an attached transmission with my target ratios.  The dimensions of the motor were also within my design intentions for the form of the handle.  I did of course not end up purchasing those motors, since the minimum was 500 and I did not want to to take the time or expense to get a sample, or track down one for purchase from a retail location.  But knowing the existence of the motor in the correct specs answered my question as to whether or not I could eventually manufacture the roasters at an appropriate price point. So I turned to my boxes of collected DC motors and plastic gears harvested from many a derelict inkjet printer.  They're free, and most importantly I could start my build immediately.  I find it best to strike while my inspiration is hot.  

The Business End of the Roasting Stick: My first issue was I was unsure of how to get a source of cheap straight steel wire without buying expensive steel rods.  I was all ready to devise a machine with a series of pulley's that would replicate the industrial machine for straightening wire. If you have read my previous intstructable "Serious Homemade Manufacturing Equipment on a Shoe String Budget" you'll know I have no fear of getting all homemade on traditionally industrial manufacturing tech. Fortunately for me Instructables.com is there to save me from my eagerness. Thanks to rimar2000's  instructable I learned an amazing trick on how to straighten wire.  Even thick gauge wire. It can even be done fast enough to be a viable cottage manufacturing solution for my weenie roasters. Once that was learned, I went for a spool of old 3/16" thick steel wire left over from a previous project.  We'll talk more about the details in the welding step of this instructable. 

Now we are on to drawing up the designs and fabricating the parts.