Hello and welcome to my blog. What I'm doing here is documenting my personal expression of "hands-on history" from a craftsman's perspective. I've been on this path for a large part of my life and it's taken me to some interesting and challenging places. I hope to share the processes and the historically inspired objects I've crafted along this journey into our past. This adventure has deepened my appreciation for past craftsmanship and the intelligence of common place things in Early America. Besides, now I have all this cool stuff to play (teach) with.


Jim Miller




Wednesday, June 12, 2013

Making a Working Model of Eli Whitney's Cotton Gin

    My wife's consuming interest in history rivals mine at times and her latest endeavor is a good case in point. She is currently raising a mini-crop of naturally colored organic cotton to learn about the plant and its product.


Some of Lindy's Cotton, Day 67
Photo by Lindy Miller 2013
     Further along into this project she hopes to become a good cotton spinner as well. Since cotton comes with seeds mixed in the fibers, my part in all this is to build her a working model of Eli Whitney's Cotton Gin .That way, she can process her anticipated cotton bolls with historic flair and eventually do demonstrations as well.


 Patent Drawing for Eli Whitney's
Cotton Gin
Image Courtesy en.wikipedia.org

    Patented in 1794, the Cotton Gin in retrospect has a dark side to its history. Before its invention, cotton seeds had to be laboriously removed from the fiber by hand. In general, this time-consuming process held back any large scale production of cotton until Whitney's revolutionary machine arrived.

    Once mechanical ginning was established, cotton production soared in the South. Some historians today name the Cotton Gin as the root cause of the Civil War. I think that's a bit of a stretch but it did play a part in the expansion of slavery even though it was intended to reduce labor.

    In order to build a working model, I had to understand the basic function of the Gin. The three key elements in Whitney's design are the rotating claw-like hooks (that grab the cotton fiber), the slotted comb that they rotate through (the narrow width of the comb's spacing keeps the seeds from being pulled through by the hooks) and the rotating brushes that remove the seedless (ginned) fiber from the hooks.

               
Original Patent Model
Note the Ginned Seeds in the Lower Front and
the Cleaned Cotton in the Upper Rear
Image Courtesy history.com

    I started by studying the 1794 patent drawing but was disappointed to learn that the accompanying description is unavailable. Two original models of the Gin have survived, one is the patent model and the other a later version used in the court battles against infringement. After studying the few pictures of the models online, I finally figured out the mysterious curved, springy comb that allows the ginned seeds to fall through.


Close-up View of Another Early Model
Note the Hooks, Slotted Comb and Springy Wire Comb
Image Courtesy of newsdesk.si.edu

    My first attempt at making a wooden drum with hooks was a dismal failure. I drove wire nails into a large dowel and cut them to length. After bending them all into directional hooks, it started to look pretty good. What I discovered was, the hooks tended to rotate, which doomed their chances of proper alignment with the all important comb. Whitney had used flat metal hooks but I didn't see myself cutting out a bazillion of those little things.


My Version of the Hook Drum
Photos Courtesy Lindy Miller
2013

     Instead, I created little circular saws in sheet steel similar to what was used in a later patent improvement by Hogden Holmes. In order to build up a cylinder, I sandwiched my little sawblades between discs of 3/8" plywood. Once stacked, I ran two small steel rods through on either side of center and riveted their ends over washers. I squared the center shaft hole by driving a piece of 1/4" square stock through the existing 1/4" round hole. The finished drum turned out to be about 4  3/4" long by 3" in diameter.




View From the Top
Showing Hook Drum in Place, Spring Comb
and One Brush Section
    The rotating drum is the heart of the machine and everything else is built around it. I constructed the housing box of 1" x 6" #2 pine and sized the inside to accomodate the length of the drum. I could only guess at the overall size of the box as this was quickly becoming a design as-you-go project. Next came cutting out the steel comb, which had to be curved to hug the drum but still allow the free motion of the hooks.

    The rotating brush drum was created using a 2" dowel and four sawed out sections of a new scrub brush. Little by little, it was starting to come together. The previously mentioned curved, spring comb thingy had to angle into the rotating hook drum at such a degree to cradle the raw cotton. I made mine removable as that's what the orignal model appears to have.


The Finished Model Cotton Gin
Showing the Completed Brush Drum and Pulleys

   Last but not least was the crank handle (mounted on the hook drum shaft) on one side and the two pulleys on the other.  The ratio of my pulleys is approximately 2.5 to 1. For a belt, I used a rubber band and twisted it in the middle to reverse the direction of the brush drum pulley as per the orignal design.


View From the Other Side
Showing the Crank and Slotted Comb

    Now came the test. Luckily, my wife had some unginned cotton bolls so we didn't have to wait months for her crop to mature. Cranking away,  it made this great primitive machine noise and the best part was.....................the darn thing WORKED and................. my wife is happy. Mission accomplished !

            To see a demonstration of the model, use the link below to go to Youtube:



                                  https://www.youtube.com/watch?v=QPPfFHF7nvg

 If you would like to build this working model, you can purchase a complete plan from us on Ebay. Just search Ebay for Cotton Gin Plan.
                                                      

27 comments:

  1. This is great! Something I've wanted to do ever since moving to Georgia. Would you consider producing plans or a kit?

    ReplyDelete
    Replies
    1. Thanks Dan,
      My wife has almost talked me into producing a pattern. Stay tuned.

      Delete
  2. will you build a kit and what would the kit/parts cost. I can put together but do not available tools to cut out stuff...E-mail me at Mred854@gmail.com. I am a history teacher and would like to have this to show my students...

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  3. is that a steel dowel on the brush drum??

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  4. It's a square steel shaft on the pulley side of the drum and a screw on the opposite side.

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  5. im sorry i meant what material is the brush drum...

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  6. I appreciate your interest. The brush drum is a solid wooden dowel.

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  7. Replies
    1. Yes indeed. Works great. Check out the youtube video and see for yourself. The link is at the bottom of this posting. Thanks for your interest.

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  8. How much does it cost in all when your done?

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    Replies
    1. Greetings,
      Do you mean after you build it yourself ? Not sure but I'm guessing under $50

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    2. built this w slight modifications (used saw blades not cut metal, used wooden dowels instead of the comb + vent) and it came to like $200 so b careful

      Delete
  9. How did you make the saw-type blades?

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    Replies
    1. Greetings again,
      After tracing around a pattern, I roughly cut them out with tin snips and then filed the contours of the blade teeth with a rat-tail file. Time consuming but worth it. They have nice aggressive teeth. I suppose you could use some ready-made sawblades if you could find them.

      Delete
  10. Do you have kits or ready made ones? I received 2 lawn bags full of cotton and need to process it.

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    Replies
    1. The best I can offer is the plan we sell on www.timelesscalico.etsy.com It's a pretty straight forward project that I would encourage you to try. Good Luck !

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  11. How long did this project take you to create?

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  12. Greetings and thanks for your interest. It took me about two and a half days to build the cotton gin once I worked everything out on paper and had all of the materials gathered.

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  13. Can you send me an email of the supplies you used to make your cotton gin
    My email is Christian.shaw@student.allenisd.org
    I am an 8th grader and was just adopted
    My name is Christian

    Thank you

    ReplyDelete
  14. Hay this is me again I just figured that you can not email me at that email address
    Sorry

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  15. Can you send the information to waynemayo760@yahoo.com or Waynemayo446@gmail.com thank you for your time.
    By

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  16. That was my partner for the project.

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    Replies
    1. Hello Christian,
      The supplies you need are listed in the plan you can purchase from us on Etsy as noted in the blog posting. If you are trying to figure this out without a plan, all I can tell you is everything is available at any hardware store and lumber yard. Good Luck !

      Delete
  17. I bought the plans but I have a problem.I can't seem to adjust the print settings on my printer. Could you e- mail the actual measurements of the patterns to me? I can figure it out from there. Thanks,
    Bigdan43@comcast.net

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  18. do you give student discounts because i am a high school student who would really helpful for me as a student. thank you very much.

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  19. Hello Jim i am a student in an Biotech class trying to build your cotton jim with your plans. I have ran into a slight problem with the measurements of the cut out piece and the measurement you have given for the saw blades. I was wandering if there was a mistake in the measurements given or with the cut out... Could you please Email me back at hamlinc@go.lisd.net thank you

    ReplyDelete