Step 2: 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. 
I didn't mean to put 2 comments lol<br/>
First thing to come to mind at coconut shells: <br>&quot;Do coconuts migrate?&quot;
Funny and inventive! <br>Love the various references.... <br>Monty Python &lt;3! <br>
Good job with the reference! I wondered if anyone would figure that out. It's almost like I need to give you a prize... Wait. I've got a good idea. I have some extra pro memberships from contests I've won, and featured instructables. Would you like one? If so, let me know and I'll get it to you.
Well, I have actually been looking into pro membership, but I would like to try some of the features (esp. badges), before committing... So sure if you don't mind, I would love it! I am actually surprised no one got the coconut reference, it's (to me at least) one of the more &quot;catchy&quot; jokes in Monty Python... of course with &quot;I'm not dead yet...&quot; , &quot;Bring out ye dead&quot; and so many others I suppose it's one that might get overlooked from time to time.... <br>There was a showing of Monty Python and the Holy Grail in Philadelphia over this weekend, but I wasn't able to go.... It's a bit depressing cause here in Dover (Delaware) there is only one movie theater- in the mall... at it's a small theater.... Anyways enough lamenting for the &quot;dead&quot;!<br>I would appreciate a pro membership, and after trying it out I might be convinced to buy in.... <br>(I've been on here since Summer of 2007, before they had membership, so I actually have some membership benefits, like viewing all steps on one page and downloading PDFs. Though I lack being able to download the e-books and creating badges)<br>I also looking forward to no advertisements.<br><br>Thank you,<br>~ (DJ) Electfire (amongst many other names)
This is truly a device of extreme awesomeness. You have a fortunate son! <br> <br>5 stars and following!
Thanks, much appreciated.
I love it! A couple sugestions: <br>It looks like you used chip board for the handle. I like to use scraps of composite decking. it's a more homogenous material and finishes up nicely. <br>for a great transmission, tear apart a lawn sprinkler of the kind that sweeps back and forth. they have a multi stacked planetary gear system that gives a lot of reduction in a very compact space. <br>I also liked the other suggestions of a thermocouple to power it and an ejector.
The composite decking is a great idea, if only i kept it on hand... I tend to have copious amounts of particleboard stocked for prototyping parts, because it cuts so easily and quickly, But I think I will need to get some composite decking to add to my stock pile. I think they use a mixture of HDPE, wood, and some binder resin. Or maybe the HDPE is the binder, and they just heat it up. Either way it's a great idea.
Nice work. Perhaps a solar panel or thermocouple could work to power the turning motor. Plenty of infra red there, but I'm not sure which wavelength most solar panels are designed for.
That's a really good suggestion. The thermocouple especially intrigues me.
That's very nice. <br>Have you considered a sausage ejector for the next model? I'm thinking of a lever at the handle that pulls the fork tines out of the sausage when it's cooked.
I like how you're thinking there.
Very well done.
I started reading and though this needs a motor! Kept reading and was stoked that you included one!
Yeah without the motor it loses a lot of the over-the-top quality that makes it what it is.
I think this wins my &quot;Over Engineering Of a Normal Object For The Win&quot; award.
Genius and super fun. I'm going to need to make some of these. :D

About This Instructable




Bio: I'm a product designer, who believes in working backwards. Instead of taking technology and seeing what problems I can solve with it, I take ... More »
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