Building Customized Caterpillar Toys

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Toy customizer Jon Stiles converted a 1/25-scale gray Conrad Model Toy Co. Caterpillar Sixty into a logging cruiser, typical of those used in the forests of the Pacific Northwest. He added a lot of detail, like a convertible top, which was rare in the real world because they were often quickly torn off when working in the forest.
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 In this conversion of an NZG RD8 into a Caterpillar D8 logging crawler, Jon added a cable winch, a covered overhead canopy, sweeps to protect the engine area from damage, and other small details.
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Jon added a canopy and winch with log boom to make this Caterpillar D82U logging crawler. It was originally an NZG RD8 model.
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A Caterpillar D8 cable dozer with a LeTourneau dozer blade, overhead cable system and LeTourneau rear control unit. Those parts all came from an NZG World War II-era Caterpillar D7.
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An RD8 was converted to a Caterpillar D8, with a hard nose, partial engine covers and supports, and a large cab.
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Front view of the converted Caterpillar Sixty diesel.
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Various details show on a customized Caterpillar Sixty diesel crawler. Jon says he has far more ideas for customizing construction toys than he’ll ever have time to finish. “They come at me from a million directions,” he says. “Ideas are just everywhere.”
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The Caterpillar Sixty diesel shown here was converted from a gray Conrad Model Toy Co. Sixty. Added details include a starting motor, cab with sliding doors, windows and muffler.
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An AMT/Ertl 1/25-scale Ertl D8H plastic kit with custom-built pipe layer boom and weight system added.
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Jon shows off some of the customized Caterpillar models he’s made. The table display also includes pieces he’s bought from others.

Not everyone would drive 200 miles out of his way just to take a photo of a vintage brush plow. But Jon Stiles, Deer Creek, Minn., brings unusual passion to his hobby of customizing Caterpillar tractor toys.

On a recent drive in rural Minnesota, Jon spotted a large, single-bottom brush (or ditch) plow. “I didn’t have a camera with me, but the plow impressed me enough that I actually drove back a couple hundred miles to get a picture of it so I could put it on my wish list,” he says. “I should stop doing things like that, because I have more projects backed up in my brain, and on pictures, than I’ll ever have time to do.”

That kind of dogged determination and attention to detail, is what makes Jon’s customized Caterpillar toys striking and unusual.

More than kid stuff

Jon has been customizing toys all his life. “When we were kids, we didn’t have money for things like toys,” he says, “but one time I got paid for threshing for a neighbor and bought a couple of John Deere tractor toys for $1.25 and $1.75.”

Both had narrow fronts, so Jon began a process that still serves him well today: examining his world to see what pieces or parts or methods would work for customizing. “I knocked the coating off a welding rod, cut off the front wheels of one of the toys, inserted the welding rod as a front axle, replaced the wheels and I had a wide-front tractor, which wasn’t made yet in those days.”

It was crude. The entire front end turned off-center, but he didn’t mind: He had a wide-front tractor. “I’ve always looked at things and tried to figure out how to do them differently,” he says.

Jon started collecting farm toys in the 1980s, displaying them on a shelf in a video store he and his wife, Lucy, owned. The next step was buying custom-built farm toys, until they became too expensive. “There was a lot of re-manufactured stuff showing up,” he says. “I didn’t know the difference between the original and the one made last night, so I just thought I’d better quit buying them.”

Instead, he turned to 1/25-scale plastic trucks. “Everybody had them under their tables at farm toy shows, but nobody wanted to buy them,” he says. “I liked the detail and started collecting them.”

For variety, he made a few lowboy trailers, but then needed something to set on the trailers. “On eBay I saw Sherwood Models Ltd. 1/25-scale D8 Caterpillar toys made by Ray Clifford,” he recalls. “I wanted them so bad I hurt, but I couldn’t afford them.” Then he found Sherwood conversion kits, bought them and wanted even more detail. “So I started adding more detail, and got in deeper and deeper.”

Learning process

Though his first customized toys weren’t accurate, they looked good to Jon. “I’d say, ‘If you find things wrong with the toys I’ve made, you’re standing too close. You need to step back a little ways,'” he says with a laugh.

Before he began customizing Caterpillar toys, Jon had no experience in the construction industry, a fact that surprises people who see his models. In fact, he had never seen real construction equipment until a road was built in front of his family’s house in the 1950s. “Nobody in that area of Minnesota had a crawler or anything like that,” he says.

After making his first less-than-accurate toys, Jon began to examine construction equipment. He talked with construction people and learned from show-goers who pointed out the errors in his toys. “They didn’t do it in a mean-spirited way, but were just helpful,” he says, “and I appreciate that.”

Eventually he got involved with the Antique Caterpillar Machinery Owners Club and began making more accurate toys. “The more customizing you do,” he says, “the more you grow.”

Sometimes Jon’s work is deliberately inaccurate. On those occasions, he may not have a photo to work from, or accuracy may require an inordinate amount of time or money. He keeps it all in perspective. “They don’t have to be perfect,” he says. “They’re just toys.”

For example, cab door and window dimensions aren’t always exactly scaled. “On the real ones, windows were about half as high as the door, so that’s how I made them on the toys,” he says. “Or the doors on my models aren’t as wide. Things like that can be incorrect, because the toy is going in my collection.”

He might make a cab roof protrude further in front than it would on the real cab, because it’s more pleasing to his eye. “I like the overhang a little longer than on a factory-built cab to help balance things out.”

He’s only sold a handful of his customized toys, mostly to other collectors in exchange for favors. “I know they’ll appreciate it, and I don’t sell them for the going rate, so to speak,” he says. “Mostly I do them for my own collection, and it keeps growing.”

Parts man

Jon excels in finding unique parts. From hobby shops he gets miniature nuts and bolts, and he bends brass wire for oil lines and fuel injector lines. “You can use various sizes depending on what you’re trying to replicate on an engine.”

But one of his best sources is a craft store. “I go with my wife and sister and am amazed at what I find: Iron-on rivets make wonderful headlight inserts, jewelry chains make wonderful log chains at about a third of the price, little jewel reflectors for truck taillights. They come in sizes just right for tail-lights or small size reflectors, in yellow, red and various colors.”

Craft store clay, available in a rainbow of colors, is another resource. Jon shapes the clay into a generator, transmission, hydraulic tanks or whatever, then bakes it in the oven. When it’s hardened, he drills a hole and pins the piece in place with a tiny brass rod or bolt.

Craft store beads are also useful. “Some are perfect for pre-cleaners on air cleaners,” he says. “When you custom-build, you never quit looking for things you can use. It doesn’t matter what it is, I’m wondering if I can use it for something I can build.”

For example, $3 remote-control toy Caterpillars. He removes and uses their wonderfully-detailed little hydraulic cylinders. “Buy them for $7-16 each,” he says, “or find them cheap and already made, which is faster and easier than making your own from brass and aluminum tubing.”

Multi-tasking tools

Jon uses an old Vac-U-Form manufactured in the 1960s by toy maker Mattel. “You heat plastic, lay it over a part and pump on the vacuum handle until the plastic snuggles around the mold,” he says. “I built my own umbrella mold and use the vacuum form machine to produce umbrellas. I started making my own belly pans (protective plates placed under the engine to prevent oil-pan punctures while logging). You never stop discovering what else you can do with something.”

Other tools Jon relies on include a small bench-top drill press, hand tools, cordless drill and files. His most important tool, he says, is a CNC rotary milling/engraving machine with a 25-by-50-inch table. “I do a lot of fabricating with that, building cabs and cutting parts out of flat stock,” he says. “I can spend hours designing and getting a part figured out, and make a thousand of them in the next hour and a half. It’s turned out to be the perfect machine for what I want to do. Today’s technology is astounding.”

The main one

Jon’s favorite construction toy to customize is the Caterpillar RD8 manufactured by Germany’s Nurnberger Zinkdruckguss-Modelle GmbH, commonly called NZG. The crawler is readily available, adaptable to conversion, and lots of parts are available. “The real D8s had so many variations that you can customize a lot of them and no two are going to look exactly alike,” he says. Jon has converted about 40 NZG toys, adding more realistic tracks, levers and controls, half-width seats, hydraulic tanks, sweeps and winches.

His greatest enjoyment comes from taking an idea to fruition, figuring out how to make parts, pondering what to use to make the pieces and then accomplishing it. “Sometimes I’ll wake up in the middle of the night with a great idea for something I haven’t been able to figure out for a month,” he says.

His customized Caterpillar Sixties from the 1920s are his favorites, he says, “because they helped build America,” and were some of the first Caterpillar-brand crawlers produced. “Those early machines are very basic,” he says. “We’ve altered them and improved them tremendously, but the early ideas are still the heart of those machines.”

Jon encourages people to pick up a file and drill, and take a hacksaw blade to a shelf toy. “Once you make the first cut, it’s history,” he says. “It might be hard to make that first cut, but once you do, you’ll be surprised at what you’re capable of doing. If it doesn’t work, it’s not the end of the world. Don’t give up on it. Try something a little different. If it still doesn’t work, you can always buy it from somebody else.

“Many people say, ‘I couldn’t do that,’ but that’s not so,” he says. “I couldn’t either, but most people can’t because they don’t try, or they give up before they actually do it. It doesn’t happen overnight.” FC

For more information: Jon Stiles, (763) 323-0724; email:

Bill Vossler is a freelance writer and author of several books on antique farm tractors and toys. Contact him at Box 372, 400 Caroline Lane, Rockville, MN 56569; email:

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