Joe Martin Foundation "Metalworking Craftsman of the Year" award winner for 1997
Jerry's 1/8 scale tractor completed and ready for paint. It starts with a twist of the flywheel. (See video link below.) (Click on photo to view larger image.)
If you haven't already done so, read more about Jerry Kieffer, his background and his quest for total scale in his introductory page. There you will also find links to other model engines, tools and clocks he has made.
Jerry's original goal was to build a model to absolute scale in every respect and yet still have a running four-stroke, spark plug ignition engine that would run on gasoline like the original. The idea was to have the tractor run at under 1000 RPM and start by rotating the flywheel in the same manner as the full-size version. Starting by hand and running under 1000 RPM is generally not a problem if you can enlarge the flywheel until you achieve your goal; however, in this case the size of the scale flywheel had to be maintained. A flywheel of a size needed to get the desired performance would have been hopelessly oversized and looked ridiculous. The problem was solved by reducing the compression ratio to just under 4:1 (normal would be 6 or 7:1) so a scale flywheel could be used. Several other things were also done to reduce friction as well as making improvements in the air/fuel mixture. Fortunately, the tractor will still start by rotating the flywheel by hand as on the original. In the video, the tractor can be seen operating between 600 and 800 RPM and will rev up to 2000 RPM, although this would not be desirable as it would be well above the speed of the original full-size tractor. It is hoped that once the engine is broken in that it will idle down to 500 RPM or slower.
Jerry stands next to his restored 1936 John Deer "D" tractor. The 1/8 scale model sits on the fender. In this photo it is easy to tell the two machines apart, but when you start looking at photos of details it gets more difficult.
The next process was to completely disassemble the tractor and paint each individual part. Scale decals were made and applied, and then the tractor was reassembled. Jerry has supplied a video of it running (see link in the photo section above) and is demonstrating it at shows during late 2005 and early 2006. Now that it is painted it probably won't be run very often, because, like on the real tractor, this is an oily, messy process that can be hard on to clean up after, so enjoy the video or see it in person if you get the chance. Jerry also intends to make a scale tool kit if it can be determined what originally came with the tractor. A scale owners manual and possibly a scale shop manual will also be made if possible. The painted version of the tractor was featured as a centerfold in the Nov/Dec 2007 issue (#14) of Model Engine Builder Magazine.
The building that housed the original John Deere dealership still exists that in 1936 sold the prototype from which this model was built. The original tractor was purchased by his grandfather, and it remained in the family. Jerry fully restored it a few years ago while taking dimensions from each part to build this replica. Jerry is thinking about eventually building a replica of the original dealership showroom as a display for the model when it is complete, although he notes the greasy parts books on the shelves may be a challenge. He recalls visiting that dealership as a kid and coming home happy but "dirty as a pig" after about a 1/2 hour visit with his grandfather.
In September, 2009 Toy Farmer Magazine did an article on scratch built farm toys featuring Jerry's tractor. Click one of the following links to view a copy of Jerry's portion of the article. (PDF version 9.8 MB) (HTML version 1.6 MB)
(Click photo for larger image.)
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Photos that follow take you along on the
progress of a running 1/8 scale model 1936 John Deere "D" tractor. Everything on the model is made to 1/8 scale down to the working grease fittings, each with a spring-loaded ball inside. Sitting on top of the tractor in the first photo is the scale grease gun that also functions. (A detail photo is also included further down in this section.) The second photo shows the carburetor and grease gun sitting on the engine. |
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Right rear view of tractor as a work in progress |
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Right front view of tractor showing engine detail |
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Similar angle to one of the pictures above, this photo shows the tractor engine in a more complete state. The flywheel is shown on the ground between the front and rear wheels. The valve cover is on the ground between the front wheels. |
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(L) The tractor's brass radiator is fully
functional and has 20 tubes and 72 fins just like the original. It also
has 33 square headed bolts and nuts (.038" dia., 120 tpi) to hold it
together like the original. There are 167 separate pieces with 146 solder
joints. The logo was scribed and cut freehand with a .022" end mill on a
Sherline mill. (R) The air cleaner (left) has 496 holes drilled .012" to the same pattern as the original. Center is the exhaust pipe and on the right is the engine breather. |
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Fuel bowl with shutoff and two-way transfer valve are all functional. The glass bowl was ground and polished on the lathe. The functional oil pressure gage took about 80 hours to construct and calibrate. The compression release valve on the right has a primer cup and cover and is also functional. |
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When people see the tiny spring-loaded grease fittings on the suspension, the first thing they always ask is, "OK, but where's the grease gun?" This is when Jerry pulls a small case out of his pocket and shows off the fully functional scale grease gun. It pumps regular grease, a bit of which can be seen coming out of the nozzle of the gun. |
 CLICK ABOVE PHOTO to see the tractor run! (. MOV version, 14 Mb) Learn more about Jerry's John Deere tractor below the photo section. |
IT RUNS! The motor was first run in
late 2004. Now that it has been tuned up a little, Jerry has provided a
longer video of it being started and run in both forward and reverse. He
then throttles it down so you can hear it at idle speed. Click on the link
at the left to view the video file This is a 14 Mb Quicktime Movie (.mov) file, so give it time to load. (It took 1 minute
on a fast T1 linet. Nothing may indicate on screen that it
is downloading, so be patient.) Several other file formats can be chosen
below as well. Note also that all electrical components are completely contained within the tractor itself. There are no external connections needed to fire it up or run it. In addition to the .MOV file mentioned above, we have now created slightly smaller versions in .WMV (Windows only) and MPEG1 (Windows or Mac) file format. Click on links below to view them: .WMV version (11.9 Mb) or .MPG version (8.9 Mb) NOTE: These are still large files and may take a long time to download. For smoother play we recommend you save the files to your computer and then play them from your own hard drive. To do so in Windows, right click on the file name and use the "save target as" command to save it to your desktop. Then double click on the file to play it or right click and choose "Play" from the pop-up menu. If you play it directly, give it plenty of time to open. A progress bar may or may not appear during download. |
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The finished but not yet painted tractor from the left side showing the flywheel. A quarter dollar coin can be seen leaning up against the front wheel for size scale reference. |
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The radiator and right side of the tractor can be seen in this photo. |
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A rear view of the tractor shows the steering wheel, seat, controls and hitch bar. Details of the fender beading can also be seen. The next step is to completely disassemble the model and paint each part, apply scale decals and reassemble it. This is expected to be a year or more process, but we will update this site when we have photos of the finished, painted model. |
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The model has finally been completely disassembled, painted, decaled and reassembled. The final look is stunning when compared to the real tractor. In detail shots it is hard to tell the difference. Jim Clark commented upon seeing the finished model at the Black Hills model show in September, 2007 that the original tractor had a raised timing mark cast into the flywheel. Jerry got out his jeweler's loop and handed it to Jim. He said, "See the painted lines on the flywheel? Those are the scale thickness of the original timing mark." Once again, Jerry insisted that even the smallest detail be reproduced in total scale--whether you can see it or not. He even went so far as to make a scale Butternut coffee can to put over the exhaust pipe just as his grandfather had done on the original. Photos: Mike Rehums |
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Here is where we talk about how it can be hard
to tell the original from the model. In this case it is a little easier
because Jerry has left the serial number plate in original condition on
his restored full size tractor, while the model serial number plate looks
like it did when it was new. The first photo is the real tractor and the
second shows the same area on the model. Photos: Mike Rehmus |
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A rear view of the model and a closer look at
some of the controls. Yes, the tiny oil pressure gauge and oil can
actually work. Note also the tiny Butternut coffee can—a low-tech but
effective way to keep rain out of the
exhaust pipe in the old days. Photos: Mike Rehmus |
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Parts you should pay attention to: the .200"
diameter glass
fuel bowl. It is actually machined, drilled and ground from solid glass and polished. It took
seven attempts and three weeks to make this one part. It could have been
made from acrylic and nobody would have known...except Jerry. The only compromise to total scale is the slightly oversize spark plug, which was necessary to get the model to idle and run properly at this small size. The high voltage involved would travel over the surface of a smaller spark plug rather than down the tiny electrode. Unfortunately, electricity does not scale. It takes a hot spark to fire a small, low compression engine and you can only reduce size so much before the laws of nature call your bluff. |
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More detail photos. The raised "John Deere"
lettering was machined freehand on the mill and painted. Behind the grill
is a radiator that recreates every brass fin and tube of the original. Photos: Forrest Atkinson |
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Two more views by Jerry's friend and
photographer, Forrest Atkinson. One thing: If you see the model at a show, please don't ask Jerry if it was made by Ertl. |
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The tractor was displayed at the 2011 NAMES
show in Southgate, Michigan. Here are a few photos of some details of the
tractor. According to Jerry, it was difficult to drill the perfect pattern of 460 tiny holes in the air cleaner; however, even more challenging was painting it without the paint filling up the tiny holes. |
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Engine details. Decals were scaled down from the real thing and are correct word for word in 1/8 scale. The beautiful paint job includes a clear top coat, something that was probably not contemplated at the John Deere factory in the 1930's. |
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As we zoom in on details in the driver's area
you can see the tiny working gauges and even a working oil can. Will anyone argue with the fact that this is no doubt the finest model of a John Deere (or any) tractor ever made? |
If you have additional information on a project or builder shown on this site that your would like to contribute, please e-mail mecm@craftsmanshipmuseum.com. We also welcome new contributions. Please see our page at newsubmit.htm for a submission form and guidelines for submitting descriptive copy and photos for a new project.
This section is sponsored by
Makers of precision miniature machine tools and accessories. Sherline tools are made in the USA.
Sherline is proud to confirm that Jerry Kieffer uses Sherline tools in the production of his small projects.
To learn how your company or organization can sponsor a section in the Craftsmanship Museum, please contact mecm@craftsmanshipmuseum.com.
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