Scratch-built 4 HP Scale Alamo Showcases Missouri Man's Skills
Detail of the nameplate on Eric Brekke's third-scale 4 HP Alamo, which was crafted on a computer-aided milling machine. The program file for the nameplate contained 700,000 bytes of information.
It's funny how a little interest can build into something big. Or, as in this case, something small.
Up until a few years ago, Eric Brekke, Parkville, Mo., didn't have any particular interest in old farm engines. A machinist by trade, his engine interests ran towards old cars and trucks and the Detroit Iron powering them. Even so, as his skills grew, his interests likewise expanded, and he became interested in scale engines.
About five years ago he launched into his first scale project, a steam-powered road roller built from plans. With its 100-psi boiler and two-cylinder engine (complete with reversing valve), the roller is an impressive bit of work. Satisfied with the roller project, and with his interest in scales growing, Eric turned his attention to building a Dick Upsher four-stroke, single-cylinder, vertical miniature gas engine. When he finished the gas engine in the fall of 2000, Eric took his scales to the Lathrop (Missouri) Antique Car, Tractor and Engine Club show. Figuring it was simply a good opportunity to compare his skills with other scale engine builders who might be on hand, Eric never could have guessed that one little trip to an engine show would ultimately launch the creation of the Alamo engine you see here.
Right side view of the engine, scratch-built, belt-driven water pump visible in front of flywheel. The aluminum box attached to the skid is a pressure-sensitive flow control for propane.
Left side of engine, with machinist's caliper thrown in for scale. Eric made a special sheet-metal brake to form the cooling trays.
At Lathrop, Eric met members of the Mo-Kan Antique Power Association (an engine club with members in Kansas and Missouri). They admired his work, and encouraged him to get involved with the club. One of those members was Stan Ellerbeck, Excelsior Springs, Mo. 'When I saw that model and the roller, I came by and told him, 'hands down, that's the nicest thing here at the show,'' Stan recalls. Stan - also a machinist by trade - struck up a friendship with Eric, and a short while later they latched on to the idea of building a scale version of Stan's 4 HP, circa 1910 screen-cooled Alamo. This wouldn't be a standard scale, however.
First off, instead of working at a more standard quarter-scale, Eric wanted to make this engine at a third-scale. And instead of making castings, the plan was to craft the engine entirely from stock materials, machining and fabricating as necessary to build a finished engine.
It's probably safe to say neither Eric nor Stan knew just how much work the project would ultimately entail.
Eric started working on drawings in the spring of 2000, taking measurements from Stan's engine and transferring them to metal stock. The plan was to build two engines, which Eric did, and while that meant more machining time, it also gave Eric the chance to perfect his approach on making each component of the engine.
Take, for instance, the flyball governor Eric made for the scale Alamo. An exquisite piece of work, its complicated construction is a testimony to Eric's determination and his skills as a machinist. The original governor's flyballs were cast pieces, but since Eric was working with brass stock, replicating the fly-balls presented some unique problems. To make sure each flyball was exactly the same, Eric fabricated his own tools to turn and cut the flyballs. And to be safe, he made seven instead of the required six. 'One of the rules with stuff like this is you build one extra, if you can,' Eric says. All told, each governor is made up from 20 separate pieces.
Three-ball flyball governor is a thing of beauty. Note the front edge of the crank guard: Eric constructed his own die so he could form the double radius.
With some pieces, Eric first made a mock-up out of aluminum billet. The finished valve chests and mixer, for instance, are steel. By working with aluminum (which is much softer, and hence easier to cut than the steel used on the final pieces), Eric could play with the pieces to ensure he found the right technique for their final fabrication.
Eric made the base plate from hot-rolled, 5/8-inch steel, the side plates from 1/2-inch hot-rolled steel, and the front plates from 1/4-inch plate steel, bent to form. To ensure a perfect fit, he surfaced the base, machining a slight radius into it where the side plates join so his finished weld (done on the backside) would be imperceptible after a bit of file work. Similarly, Eric built the crankshaft saddle from separate pieces, which he set in pockets in the base and welded in place. This approach meant Eric could install the crankshaft (which turns on bronze oil-lite bushings) and the saddles as a unit, ensuring perfect alignment. The cylinder started as a piece of 4-inch round stock with a 1 -inch center hole, and ended up with a 2-inch finished bore. Eric then welded mounting tabs to the cylinder, followed with careful machining, welding and filing to ensure a 'cast' appearance.
The crank guard is another piece deserving mention. 'I'm real proud of the crank guard,' Eric says. 'I had to make some dies and manipulate it with a roller. It actually has a rolled edge since it's a solid brass sheet.' Making a die was the only way Eric could form the double radius at the front of the guard. 'It's all about creative solutions, and that's how I solved that problem.'
Creative solutions certainly abound on this project. The oilers, for example, are handmade. 'There are some scales available, but since this is one-third scale it's a little unusual,' Eric says. To get around that issue, Eric sourced 5/8-inch sight glass from Lee Pederson, and then built the oilers around the glass. There are three different sized oilers on the engine, patterned from a Lunkenheimer swing-top, and all the detail work on the oilers was hand filed.
While most of the engine is the result of Eric's prodigious skills as a machinist, one piece in particular was the result of modern computer technology: the nameplate. Both Eric and Stan wanted a faithful reproduction of the Alamo's nameplate, but getting one made was another issue. They tried jobbing it out, Eric says, but they were told it couldn't be done. The final nameplate was Stan's doing, thanks to his familiarity with computer-aided drafting software.
Starting with a picture of his original Alamo's nameplate, Stan then scanned the picture into his computer. 'I took it and I made a raster image,' Stan says, 'and then put that into the program. After that, I blew it up on my 19-inch monitor. Each letter was the size of the screen, and each curve was a point that I had to mark. There are bizillions of clicks in that thing. It took me two weeks to draw it.' There were 7,000 lines of command and 700,000 bytes of information in the final computer file, which was then transferred to a computeraided milling program for final machining on a CNC (computer numerically controlled) machine. 'That was our solution to that problem,' Eric says.
The 11 -inch flywheels also benefited from computer technology. Using his computer-aided drafting program, Stan drew plans for the flywheels, which were then cast by Roger Martin of Morrison & Martin Engine Works, Benton City, Wash. 'He did an awesome job,' Eric says of Roger's work. Eric, however, did all the final machining on the flywheels.
The two engines were finished earlier this year, and since then Stan's taken his scale Alamo to a number of shows, running it every time. He figures it's got about 100 hours running time on it now, and he says it hasn't missed a beat. Stan had his scale Alamo running at this summer's engine show in Portland, Ind., set up next to his full-size Alamo for comparison. It was an impressive sight, drawing a constant stream of admiring onlookers.
Detail shot of engine bed, crank assembly and oilers. Note the almost invisible joint between the side plate and the engine base. Numerous hidden details abound on the engine. For instance, Eric and Stan spent an entire day experimenting with the fore and aft position of the exhaust linkage's pivot point, making sure it was ideally positioned for proper lift on the exhaust valve.
Not one to sit around, Eric's already moving on to his next project, a scale Callahan 'cam stopper.' Eric says he'd like to build a couple and sell one. Although happily employed as a machinist, he'd like to turn his interest in scale engines into a full-time job. Given Eric's eye for detail and quality, and his ample reserves of patience, that sounds like a sure bet for the future.
Richard Backus is editor of Gas Engine Magazine. Contact him at 1503 S.W. 42nd St., Topeka, KS 66609-1265, or e-mail: firstname.lastname@example.org