Before there were truss machines, how did fabricators press plates? They were able to use hammers and nails on the Grip-Plate, but when they started using the plates that didn’t need extra nailing, they had a nearly impossible time getting them pressed. When they went to their local machine shops in search of a press, they found press-brakes, shears, and stamping presses that had enough tonnage, but these machines were meant to bend or cut steel, and any of them would pulverize a 2x4. And none of them had a wide enough throat to fit a truss through. Dade Truss was able to purchase a used Multi-Max press that had plenty of pressure, but it still had a restrictive opening and it was not exactly portable. Others had hydraulic C-Frame presses custom made, but some, like Boise Cascade’s St. Louis lumberyard, didn’t know how to repair them. When Boise called a local repair shop, they got much more than they bargained for, and so did the early truss industry.
That repair shop, Moehlenpah Engineering Inc. (MEI), discovered that Boise’s press was poorly suited to the task of building trusses and needed redesign. When the shop’s owner, Walter Moehlenpah, made further inquiries, he learned that they were also buying large loads of truss connectors from an outfit in Florida. That made him consider which would be the better opportunity. If MEI made a superior press head, they would gain revenue only once every 5 to 10 years, but if they made connectors, they would gain a continual stream of revenue. Moehlenpah decided to pursue both, bringing both products to market as soon as he could and then selling them together. But first he would build a better truss machine.
Fortunately, Moehlenpah had a mechanical engineering degree, and a keen eye for talent (see The Development of the Truss Plate, Part IX: The Case of the Century). He reasoned that he would need a top notch engineer to design a press head with the proper balance between strength and portability. So, he pursued an employee of his biggest local customer, McDonnell Aircraft Company. Providence shined brightly on Moehlenpah when he hired designer George Pallme, who worked at MEI in the evenings after his day job at McDonnell.
Pallme was unfamiliar with the design of truss machines, but he was familiar with the lightweight materials in the airframe and durable hydraulics in the landing gear and flaps of McDonnell’s F4 Phantom. So, he designed the press to be made of the same cast aluminum alloy and incorporated the proven Vickers hydraulic parts sold by MEI. He further reduced the apparent weight of the press head by counterbalancing it with the weight of the hydraulic reservoir on an overhead unit.
While the press was being designed, Moehlenpah created a new company named Hydro-Air Engineering, Inc., which was a combination of the word “Hydro” for hydraulics and “Air” for air-operated jigging. While this name, Hydro-Air, was based on machinery attributes, he worked intently on acquiring a truss plate, so that he was ready to go to market with both.
One of the first to test the machine, dubbed the Mark 6 MonoPress (see first image), was Wally Randall (late father of Alpine’s now-retired Bryan Randall) at his small truss shop near the St. Louis airport. Wally was impressed with the maneuverability and speed of the Mark 6, enabling him to quickly traverse around the perimeter of a truss, while pausing only briefly to press each joint. [For all images, See PDF or View in Full Issue.]
When Randall found he had to step-press large plates to fully seat them, Moehlenpah quickly acted to minimize that shortcoming by having a heavier, welded-steel press head designed with much increased tonnage, and with a uniquely designed, patented opening that compensated for the tendency of the plattens to open up under load.
To keep the plattens parallel while tonnage was increased, specific changes were needed. As shown in the image, it was machined with opening “B” larger than “A” and with the center of the forces offset a distance between lines “C” and “D.” These two subtle but key distinctions between this C-Frame, dubbed the Mark 8 MonoPress, and any others explains why this became the largest selling truss machine of all time.
While Moehlenpah steadily developed his C-Frame-based technology, both dominant plate suppliers, Sanford and Gang-Nail, recognized the need and were developing their own solutions.
As Moehlenpah’s truss machines became dominant in the Midwest and Northeast, Carol Sanford began offering his very early gantry system in the South, and Cal Jureit began selling his massive concrete press. However, both machines required a much larger investment than the MonoPress, and had not yet been given the same sales support that Hydro-Air provided. To attempt to capture the lower end of the market, Gang-Nail purchased the patent for a C-Frame design (see third image) from a local inventor, but I do not believe it was widely marketed, as its design pales in comparison to Moehlenpah’s inventions.
Even though Moehlenpah discovered the truss market five years later than the incumbents, he was fortunate to be able to see it through the eyes of the fabricator, and bold enough to venture into their area of strength. When faced with the choice between “the razor or the blade,” he chose both and built the foundation for MiTek, now a billion dollar enterprise.