Scratch-Built Scale Model Engines

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Dave with his Weeden steam engine, sold in the 1920s.
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Though this is an older model Wilesco model steam engine, these German-made models are still available today.
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A model of a Miraya hot-air fan Dave scratch-built.
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An intricately detailed vertical model of the International "Famous" gas engine.

If ever a man was destined to build models – in this case, models of steam engines, hot air engines, and gas engines – it is Dave Leinonen of Buffalo, MN.

“Ever since I was a kid,” the 58-year-old machinist says, “I was always making something, or tearing something apart. I lived on a farm, and my dad would use silage blowers and things like that, so I would go out and build myself a little blower and blow grass with it. I’d use an electric motor that had bare wires – I probably should have been electrocuted already – and I don’t know how many of those I made. I would wear one out, and then build another one. I was only 8 or 9 years old; maybe younger than that. I’ve always had an interest in things like that.”

So maybe it’s no surprise that today Dave’s favorite thing to do is to build working 1/8-, 1/16-, 1/32-scale model steam engines, hot air engines, and fans. But first he took a detour through the collecting of small  gasoline engines. He used to have 40 or so of the real gas engines, he says, but he’s cut down to a couple of dozen now.

“John Deere, Waterloo, Fairbanks-Morse, Sears & Roebuck, that one was made by Stover, seven or eight Maytags sitting there right now,” he says. “I sell one or two once in a while. Eventually I won’t have any of them left.”

Part of the reason he’s getting rid of the collection is the engines’ size and weight, he says, which makes them difficult to take anywhere.

“They just got to be a little bit too heavy,” he says. “And since I was always interested in making small models …”

Some of that was fueled by a little battery-powered gas engine Dave’s dad bought him many years ago.

“I don’t know what age. I had fun with it until it broke, and then I tried fixing it,” he says. “I can still vividly picture that one in my mind. I’ve been looking for another one, but I can’t find any. It would be an antique now. I don’t remember what it was called. I’ve just seen one of them since. Last year somebody had one, but he wasn’t selling. He had picked it up at a flea market somewhere.”

First, The Collection

Dave first started collecting small model steam and hot air engines. One is a model of a Weeden steam engine.

“Another collector eventually gave me a page out of a 1927 Sears catalog ad, with some pictures of it in there. I also got some information from a guy living in Michigan. They don’t make Weedens any more, so they’re kind of rare.”

Years ago, the Weeden was usually sold as a toy for kids, Dave says.

“It was fired by electricity or an alcohol burner or a dry-fuel tablet,” he recalls. “They had a few toys you could hook up to them and run, trip hammers, a little saw, drill press, lathe. I think these toys had to be bought separately.”

On the other hand, one of his other model steam engines, a Wilesco kit (still being manufactured today) comes with a drill press and saw and a couple of little men that work with it – a complete little machine shop.

The Stover and The Famous

For a couple of years, Dave had been trying to decide whether he should buy a model Stover steam engine he’d seen for sale.

“One day I had the money, so I bought it,” he says. “After I got it home and was sitting there thinking about it, I realized the size of the engines I like was with pistons of 1-inch bore or smaller. This one had a 2 1/8 inch bore, so I was thinking, ‘maybe I’ll sell it, maybe I won’t'”

That weekend at a show another collector admired it, and tucked in amongst the talking, asked Dave what those engines were worth.

“So I told him, and about an hour later, he had the money there for me, so I just said, ‘Easy come, easy go.’ I had it for a whole week,” he laughs. “Plus, I got more than I’d paid for it.”

The next weekend, Dave ran onto a model of an International Harvester Company “Famous” gas engine.

“It’s not really an unusual engine, but it just caught my eye because it’s got a lot of detail and features on it that I like,” he says. “I had the money from selling that Stover, so I bought it.”

Though he didn’t completely scratch-build the Famous, he did a lot of work on it.

“It wasn’t completed, though all the parts were made. It needed the paint and the final touches … a lot of work.”

But it’s been worth it, he says, because it seems to be people’s favorite engine.

“There’s lots of working motion on that engine, and lots of detail, and I think it’s a nice engine, too,” he says.

If You Build Them, They Will Come

But Dave’s real love is scratch-building the models, which he began in 1982.

“For years I had seen models that somebody else had made,” he says, “and then I saw some ads for information to make some models, so I ordered the plans and casting, and started building it.”

That was a model of the Associated Gas engine, called a “Little Brother,” so named because, like many of the scaled-down versions, it couldn’t be made exactly to scale of the Associated engine it was patterned after.

“Sometimes in that smaller scale, you’ve got to do a little changing of the size of parts to make them work,” Dave says.

“I get plans from people, or out of books, and I say, ‘I think I’m going to build that one.'”

Another one that he’s built is a Robinson hot-air engine.

“I made all the parts for that one,” he says. “I’ve got a mill, and a lathe, and a pliers and screwdriver and hammer and chisel, as far as that goes, so I use whatever tools it takes to do it. I don’t have a fancy mill – I have what you call a mill drill – but it works.”

Hot air was used as a power source for many years beginning in the early 1800s, Dave says.

“These engines were run by heating the air that’s trapped inside the engine. The displacer in there moves the air from the hot side to the cold side, so when the hot air expands, it pushes the piston out,” he explains. “Then, when the displacer moves the air to the cool side, the air cools and creates a vacuum, which pulls the piston back in. The big ones work the same way, only in bigger scale.”

Another model engine Dave is making is of a Lake Breeze fan powered by hot air.

“It was a fan used to cool your house in the old days. Actually, hot air was first used for power for many years, and then steam took over, because it produces a lot more power. You could pressurize steam as much as you wanted, so there was lots of push there.”

How To Do It

“When you’re going to build models,” Dave says, “they suggest starting out by making larger-size models before the smaller ones, so you get an idea of how to do it, I suppose. But I didn’t have any problems making that small Associated, probably because I’ve worked in a machine shop for over 30 years already, so things that would have been difficult for others probably weren’t for me, because I’ve already done them. The biggest hurdle for a lot of people would be getting parts machined or machining them themselves. You’ve got to know the machining tools and how to use them.”

If not, things can go wrong. Even with Dave’s experience, he still makes mistakes.

“I have my ‘oops’ pile. Fortunately, all the casting models that I’ve gotten so far I haven’t had to go out and purchase another casting because I made an ‘oops’ on it, because my ‘oopses’ happened to be fixable,” he says. “So I’m kind of lucky. But I’ve had other parts I’ve made for them, made from steel or brass or whatever material I was using, and I made a little ‘oops’ on them, and threw it into the dump and started on another one.”

In order to make a model, Dave says you either have to make the castings for the engine yourself, or purchase raw, unmachined castings. “Then you proceed to machine them, making spaces for where the crankshaft goes, and where the cylinder goes, depending on what kind of casting it is, and how many pieces of casting there are.”

Castings for one model won’t work for another model, he says, because each model calls for something very different. He did try making his own castings in aluminum once, he says, but not with great success, so now he leaves that to others. Most castings for the engines are made of cast iron, or brass or aluminum, he says.

“I don’t see much of the cast steel, as far as the models go.” After the castings, “You have to drill the taps for the bolts, make the piston – on the ‘Little Brother’, the guy who made the castings sent me a chunk of aluminum for the piston, with high silicone content so it would wear a lot longer. But with some of the engines, you get just the castings, and whatever other pieces you need – like the gears – you either make them out of pieces of aluminum or steel or brass or whatever material you need, or else you buy them.”

He buys pieces of particular metals from scrap dealers in the Twin Cities in Minnesota.

“Scrap dealers have short pieces off the ends of bars that manufacturers don’t want,” he says, “or scrap iron or whatever.”

But Dave says he doesn’t haunt the scrap places too often.

“I’ve been lucky. I usually manage to land into some stuff from work, or somebody has something they want to get rid of, so I’ve picked up a few of those things and used them to make different parts of my machines.”

He has occasionally had to order some pieces, like 5/8 x 1/8 inch flatiron for making his Lake Breeze fan.


Though Dave doesn’t think any of his models are especially rare or unusual, because he’s seen them around, one in particular – his “6-Cycle Oddball” engine – is the only one of its kind he’s ever seen. He got the plans from a book, and he says it’s the engine most people comment on.

“With the other ones, people will say, ‘I like that one’, or ‘That one sure has a lot of detail on it’, especially that IHC Famous, but with the 6-cycle oddball, people always ask how it works. It’s associated with a four-cycle car engine, basically, which involves two revolutions a crank (of the crankshaft.) I don’t know if they really believe you can make a small engine like that. I have to explain it all the time – the crankshaft goes three revolutions to every one revolution of the cam, which is unusual. People are always trying to figure it out. Others just look at me like they don’t believe it. That’s the only engine like that that I’ve seen around. I’ve seen pictures of them that are made a little differently, though.”

Dave doesn’t keep track of how long it takes him to make one, but in general terms, each model takes about a month of his free time.

“I started keeping track of the hours a couple of times, but then I forgot to mark the time down, and kind of lost it all,” he chuckles.

He’s got the castings and plans on hand to make about ten engines yet.

Dave takes his engines to seven different shows a year, where he sets up a canopied table, and displays the models, showing people how they run. He runs all his machines with air, because the alcohol burners tend to disappear, he says wryly.

“People like to steal them,” he says.

Taking them places presents other problems, too, like rust.

“Cast iron is porous, so it takes on moisture, so if it rains or something like that,” he says, “you’ve got to wipe them down quick, otherwise you’ll get rust on them.”

Other people have been after him to make them some models recently, he says.

“I have one guy right now who wants me to make one for him, but I haven’t given in to him,” he says. “You’ve got to have a fair wage for doing something like that, and I don’t know if he wants to pay that kind of money.”

He says if people would like to build models, they should go ahead and do it.

“If they don’t have the equipment, they should ask some of their buddies, and maybe they’ll help them. If they like it, they should just go ahead and do it. For me, it’s a hobby. I’ve worked every day at my job as a machinist since 1964, and then I come home and do more machining right here,” he says. “I’m only a year and a half away from retirement, and I’m looking forward to doing these models full time. I just really like to do it.” FC

Bill Vossler has published more than 2,300 articles in 160 different magazines in his writing career, and is a regular contributor to Farm Collector.

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