A man who works with his hands is a laborer; a man who works with his hands and his brain is a craftsman; but a man who works with his hands and his brain and heart is an artist.
The pursuit of a good design
I grew up with my grandfather, a small man not taller than 5 foot 4 inches, whose hands were nothing short of art. Soft, battered, yet strong as iron, I would give the world to know and see what those hands had accomplished. It was then that I realized that my hands would be no different. Allow me to tell a shorter story about my hands.
I grew up in a family that valued what you could build. It was not that laboring was so much the onus, but rather that we recognized our purpose in sorting out the trials of life. I was raised with a father who built custom cabinetry of the finest quality, and my grandfather bought and sold machinery. I managed to instill my father's demand for perfection in my grandfather's work of machines and solutions.
When I was 19, I began working on three type-five fire trucks. There weren't designs to follow, just solutions to actualize. It all had to work together. A separate diesel Engine was pumping water while the truck bounced over the uneven terrain, attempting to extinguish a wildland fire. All the while, the driver was steering and manipulating a remote nozzle at the same time. In addition, it needed to work for a very long time, with every part easily replaced and accessed. I had a 6" ruler and a pencil at this early stage. When I felt ready to build my design, I would trace it in black pen. This was the beginning of the iterative process, and I had yet to make a single cut or weld. What I quickly learned was that my first design was rarely perfect. Neither the second nor third iterations. Each time, my paper design was crumpled to the floor as version 2.0 progressed to version 10.0. In that early phase, where 3D CAD was still a nascent reality, I had figured out that if I made a basic drawing of plotted dimensions and overall shapes, I could copy it ten times and save time with the various iterations. I could not get my hands on CAD soon enough.
Experience made the design process more straightforward. At 19, I had been in this business working on these rigs since I was 10. Whenever a part failed and had to be replaced, I would ponder its demise over coffee with my grandfather. The most crucial answer was 'why'. Why did this part break? How can we make it so that it won't ever fail again? One such detail was the Victaulic fitting on the bottom of a water truck that fed the water pump from the tank. It had fractured the PVC fitting into pieces. It wasn't just broken; something was miscalculated. It turned out that semi-truck frames are designed to flex as they traverse rough terrain. Trucks can flex several inches as one tire rolls over a rock, unlike a car that can measure the vibration amplitude by the millimeter. That fitting I had designed out of PVC would never work with that kind of flex. The solution? Hard suction hose. The problem was solved because I finally understood the principle behind my error.
The design is more than crafting something in your imagination. In truck mechanics, it is the intersection of vibration, harmonic frequency, temperature, leverage, Electrolysis, and more. Because I had worked on many pumps by the time I built those fire trucks, I had come to understand the cancerous anomaly that is Electrolysis. Because of its minerality, this ionic charge in water can bore holds in pipes and eat soft metal to nothing. Years later, I would take chemistry as part of my HAZMAT training and better understand how to mitigate this issue. At the time, I knew only one metal could resist that problem: stainless steel. The entire plumbing system was hand-built based on that chemistry, which is one of the many reasons why those trucks have lasted so long. Eventually, I would learn the power of Anodes, which act to discharge those ions in the water before they get to the soft vanes of the pump impellers.
Proposal #1:
Computer-aided design is the launching pad and landing zone for the iterative process.
The Kenworth Front clip
Those fire trucks and so much more were all in my past when I finally started working with Fusion 360. Nine years later, I was designing a suspension system for my low-rider semi-truck and needed to get it right first. This truck would drive one hundred miles per hour and required to take on massive forces with ease. This was the Crazy-Kenworth, and getting the precision yet almost toy-like dimensions and proportion would need something that had never been done. The criteria for the front of this truck were critical. I was designing the front end of my low-rider semi-truck. The look I was after was the quintessential 20s hotrod but in a semi-truck form. This means the tires were quadrupled in size. The track width of the front axle was over nine feet. The original wheels have a reverse-style offset, so the steering pivot was just inside the lug nut face.
The new proportions would require the opposite offset, and the outside tire track had ten times the leverage on the steering shafts and the steer pivots. This then involves steering linkage with much more robust construction. This whole time, I wanted the front body to lower around the front axle. In addition, I wanted it so that you could see the tire as the foremost point of the vehicle. Back in the 20s, that was a crucial detail. This job needed time, CAD, and every physical perspective I could bring to bear.
Metallurgy:
Growing up welding meant I had a unique appreciation for metal quality. In this case, it was the axle of the 1960 Kenworth. This axle was made in America in the '50s when our plants were the industry's best, and the quality of our mineral was world-leading. Old-school steel forged into this axle was the most robust metal available. I wanted to keep that axle but knew I had to develop a design and weld plan that worked with that metallurgy. The tinsel strength was less than that of spring steel but enough for the correct heat treatment to be successful for the welds. The design must be interlocked with cold-rolled plate steel, where no single weld took all of the torque, but rather, the steel plates took the load, and the welds merely kept the plates in the correct orientation.
Leverage:
Try lifting a car by hand. It usually only goes well if you decide to use leverage. Even Pascal's Principle is a form of leverage and would be helpful for lifting your vehicle. The front clip of the Kenworth could be described as a leverage transfer device.
We will start with the most obvious: ups and downs. There are two airbags about 10" in diameter and capable of lifting more than ten thousand pounds. In addition, these bags fold over themselves to compress from 10 to 30 inches tall. This allows the front of the truck to go from sitting on the ground to as high as twenty inches off the ground. These bags are standard truck parts but can only lift up and down. There is no lateral stability or shock-absorbing capacity.
The front axle must be in front of the diesel motor so the truck can reach the ground. When the Crazy-Kenworth is lowered on the ground, there is less than ½ of an inch between the top of the hood and the motor. This means that if the motor were taken out of the truck, it would sit just as tall. This does not offer much room for the rest of the truck unless you are willing to engineer. I then had to design control arms that held that axle from tipping forward and backward, from moving left to the right about the truck frame, and finally allowing the full twenty-inch range of motion up and down for the axle. Every vehicle has a version of suspension that solves all these problems, but when you decide to extend the wheelbase forward by three feet so that the tires are the foremost part of the vehicle, the leverage and resulting pressure on those control arms goes up exponentially. The goal was to combat leverage with leverage—the normal points connecting on the axle are about 4 inches apart. I decided to use every inch available under the hood. This means that the front axle would need a core extension in the middle to grab the top of the axle 30" above its typical spot. This extra leverage has its most significant value when we describe the action of the front brakes. When applied, the braking action will cause the front axle to pitch forward as the weight of the entire truck at speed is harnessed, and the brakes slow the vehicle. If the top contact point is below the height of the brake-pad/rotor contact point, the leverage on the control arms increases. The leverage decreases proportionately if the contact point is above the rotor/brake-pad contact point. This concept helps to describe the value of placing the front axle control points 30 inches apart from top to bottom with the top control point twenty inches above the axle. The pictures below will help to orient your mind to the beauty of this design.
Steering:
Not only does the front axle have to bear the vehicle's weight and handle the brunt of most bumps greater than 80% of all stopping, but it also needs to steer the vehicle. Picture yourself in a boat. If you push away from the dock, your boat moves. However, you would not be very effective if you wanted to push the dock anchoring from your boat unless your boat was much larger than the dock. The same principle applies to the steering of the front axle. If the axle is not anchored to the frame to take a lateral left-to-right force, every time the steering wheel attempts to move wheels, the axle will swing. Most straight-axle vehicles run with a track bar to do just that exact task as it connects the axle to the frame parallel to the front axle. In the case of the Crazy-Kenworth, the airbag placement with the rear steering linkage would not allow enough room for a track bar. In addition, twenty inches of motion in an axle would cause any track bar to move axle swing from left to right as the bar rotated. The solution was solved by combining the upper wishbone control arm and the bracketing of the lower control arms. The control arms can then go up and down but not left to right. In addition, since the upper control arm links were so high, the center of gravity was about 12 inches below the connection. This meant the front of the truck could hang from that point, allowing gravity to do most of the work and keeping the axle under the truck. The lower control arm braces would apply when the vehicle's motion caused an offset of the center of gravity.
The final step was taking the vehicle from manual to power steering. I added a hydraulic pump to the diesel engine, upgraded the steering box to a hydraulic-powered unit, and can now drive in modern comfort.
The body and frame:
This final task of the front clip was to perform its duties as part of the frame. This clip needed to hold all the body parts, the engine, and the front half of the frame to the axle. We already covered how the axle is held to the clip; now, we will speak to how the clip is held to the frame.
The Kenworth was specifically selected for its unique body style. In addition, based on the nature of grandfathered rules, any rule made after its manufacture was not binding and up to the owner to upgrade. One such upgrade was from manual steering to power steering. Due to the age of this vehicle, it was subject to the rules of the road at the time. Back then, the max payload was less than today due to the lesser tire technology and lower weight restrictions. Manufacturers would build aluminum truck frames and bodies to combat this issue. This aluminum-made truck is a perfect hotrod project, as rust was not a concern. In addition, the chassis was light enough to be under thirteen thousand pounds and could then be labeled as a collector vehicle without concern for Commercial vehicle laws. For the above reasons, the truck was almost entirely made of aluminum other than the engine and several reinforced parts on the frame. Aluminum is flexible but not nearly the tinsel strength that steel can provide. For this reason, the engine carrier section of the frame was reinforced with steel internal gussets all riveted in place. These gussets were critical for mounting the new front clip in place. All these details on force and leverage would be wasted if the clip could not become one with the frame. This meant the front clip had an internal dilemma, as it had to form itself snugly around those internal gussets and the diesel engine. This part was where 3D CAD has great value. I could easily transcribe measurements and carefully develop a cut sequence of shapes and parts that would match perfectly. The picture below can help for reference.
The Radiator:
One final concern was cooling. As the body surrounded the large engine, this truck needed to stay cool. At first glance, the reduction in airflow was a possible concern. Luckily, the old-school efficiency of these diesel engines works to my benefit. For example, in the winter, the engine runs so efficiently that it needs to close off all air through the radiator to keep the driver warm. In this case, the reduction of airflow was of no concern, combined with the fact that I would only be using it for 50% capacity from now on. I added on-demand electric fans to the radiator should the coolant temperature rise above 200 degrees. To date, this occurs a couple of times a year on the hottest of days.
Conclusion:
Zen and the Art of Motorcycle Maintenance is a treatise on Quality by Robert M. Pirsig. I read this book about five years ago, and it was as if the author had read my soul. I knew then that art was not just for me but the unique discovery of every soul. Quality is the essential question of art. What is it? How can I recognize it? And if I see art, why can't others? The Crazy-Kenworth is one of a lifetime of projects where I explore physics, mathematics, science, and art on the same canvas. I have been gifted with the proclivity to wonder, I suspect from the influence of my grandfather so many years ago. I see a world with incredible complexity yet unforgiving natural laws. My iterative process combines discovery through science, physics, mathematics, and adventure as I test my understanding and study to my own perceptions and experiments.
Please refer to these designs for clarity.
The art of a good weld.
The capacity to bind a joint is at the very foundation of any version of construction. In the woodworking world, we can spend hours debating a finger joint, biscuit joint, glue with nails, and many more options. The metal world is no different. We started binding metal with rivet joints and forging until Westinghouse introduced electricity in 1893 at the World's Columbian Exposition in Chicago (Larsen, 2003). While the medium of hot weld bonding molten steel into one product is vastly different in its molecular nature, the capacity of metalworkers to construct relies equally on a good joint. This next chapter in my craft examines the myriad of factors surrounding a good weld joint. I started welding when I was about eight years old. My grandfather told me to find a piece of metal and practice making 'Chicken-crap.' The weld bead in my nascent learning stage closely resembled that description. As my time on the tools increased, so did my iterative understanding.
When metal reaches a temperature hot enough to bond with another metal, the likely reactivity to the natural oxygen in the air is guaranteed. This requires the presence of a shield gas. Depending on the metal, the mixture of shield gas will vary. The following weld units will be described in detail to show how simple yet complex welding can be.
Arc Welding:
In the simplest form, Arc welding is a steel alloy surrounded by a casement of flux that, when heated through electrical arcing, will melt the outer casement into a slag puddle that rises to the top of a molten weld bead. When laid properly, the slag on the top of an Arc weld can be lightly tapped off to reveal a 'row of dimes,' the classic description of a bead with consistent form and heat. The value of arc welding lies in its simplicity. The power unit is relatively cheap, requiring AC or DC amperage with a hefty ground and a positive electrode clamp that holds the welding rod. The decision comes down to selecting the right rod (Metal alloys are within each casement), the current type, and the amperage setting. The weld rods are numbered in a way that articulates their tinsel strength and thickness. The 7013 rods will have more robust strength characteristics but require higher amperage. They prefer direct current vs. 6013, which holds a lower heat bead with alternating or direct current. After several years of this kind of welding, I could rapidly select the correct rod based on whether I was welding a Dozer blade or a thin piece of sheet metal. This welding is preferred in lousy weather, dirty substrates, or underwater. Additionally, any truck generator can produce enough current to run these in the field. When designing a fence or rail that needs to be welded together on the scene somewhere, unfortunately, when we cover the powder coating, we will find that I avoid on-scene welding as it is suboptimal for the final fit and finish.
Mig Welding:
Metal-inert-gas. This more complex tool varies in size from a suitcase welder to a massive unit held by a crane. While the size varies, the mechanism of action does not. The wire comes stock on a spool. We buy this wire in certain sizes based on a gauge of 030, 035, 045, etc. This merely tells us how thick the weld wire is and requires that we have matching drive sprockets in the MIG unit. The MIG unit can be regular ground or positive ground, meaning that the flow of electrons can be reversed based on how the unit is configured. For example, a dual-shield wire has a hollow core filled with flux, like the arc rod casement, forming a slag layer. The dual shield uses both flux and shield gas and requires a positive-ground setup that is reversed to standard MIG. The wire runs past the grooved sprockets that have been selected with care to match the wire. This sprocket assembly also charges the wire with a positive or negative current that will eventually contact the grounded metal surface and arc into a pool. To keep the weld pool stable until it cools, we must blow a shield gas on the molten steel through the casing surrounding the wire. Ultimately, you have a whip with a handle and trigger from which a wire feeds while gas flows around it. This tool is much easier to learn and delivers reliable welds, assuming you understand some core ideas.
1: Welds are very reactive when metal is molten and nearing the plastic state. Every metal is an alloy mix of iron, brass, and many other elemental metals, so each metal has a correct gas. Stainless steel will not work with CO, but CO and Argon mix will work. Pure Argon works with stainless steel but will look different. The final weld results from the wire, the metal being welded, and the shield gas. All ingredients will change the weld joint's looks, strength, and overall outcome.
2: Wire-speed and current depend on metal thickness and the gas used. When Argon is mixed into CO as the shield gas, it changes the heat characteristics such that you can increase the wire speed without burning through the metal. Pure CO as the shield gas will create a flatter and more penetrating weld but can also over temper thin metal, rendering it very likely to fracture.
3: Weld's temper along the bead edge. In this regard, welding can be like folding a paper airplane. If the force applied to a weld is perpendicular to the weld edge, fracture is likely. Adding weld fingers or a gusset perpendicular to the main weld line will prevent direct force on the bead edge and avoid fracture. This is where welding becomes more than just connecting pieces of metal; it requires understanding the forces at play.
Above are my basic rules for mig, which took twenty years to articulate but can be taught rapidly. Once you take a metallurgical and chemistry-level outlook on welding, the world opens up to a beautiful symphony of chemical reactions facilitated by mid-thousand-degree temperatures.
TIG Welding:
Tungsten inert gas is my precision welding source. Legend will speak of being able to weld pop cans back together. This tool is precise and requires all appendages of your body to operate. Once mastered, this art form of welding can be appreciated by anyone. This tool generates current like the arc welder with different Hertz amplitude and wave shape, aptly called square wave or synchronized wave TIG. This wave characteristic is valuable in metals such as aluminum, which absorb and transfer energy quickly. A tig can weld any metal, but it gets its name and fame from what it can do with aluminum and fragile metals. This precise tool uses double, if not triple, the energy of the aforementioned welding styles. Expect to upgrade your breaker panel to a 60-amp breaker if you want to get anything done. The tool itself has a torch that holds a piece of sharpened Tungsten. Like the MIG welder, a shield gas flows over the tungsten rod, keeping the Tungsten and substrate metal from reacting at high temperatures.
In like manner, the suitable gas must match the correct metal, with Argon being the default gas when in doubt. This classy noble gas also helps achieve the higher precise temperatures needed in aluminum. With the Tungsten and shield gas creating the heat flux area, the other hand must carefully introduce the compatible metal rod into the puddle one drop at a time to stack and form your weld bead. This is tricky because while careful not to touch the Tungsten and stick the metal to the cooling area, you need to titrate the current based on the weld needs with your foot on the current pedal. I compare this to freestyle swimming, with ten different motions co-occurring. This choreography must happen while balancing on your good foot. I recommend yoga to prepare for the tig machine.
Because Tig is the preferred tool for aluminum, it is time to speak about the oxide layer. Every metal will be oxidized on the outer micron layer of the surface in the area where oxygen can touch. While steel can rust and copper oxidize, the heat to create a good weld can melt the oxide layer off without requiring much metal preparation. Aluminum's alloy side melts at nearly 1000 degrees, while the oxide layer is more than triple that value. This means that should you try to weld without getting the oxide layer off, you end up with the 'water balloon effect' where the molten aluminum blob will never connect to the other metal and become deformed. The solution is in the preparation. TIG welding must be laboratory-level clean, with no chance of carbon near the weld. This will add impurities to the weld, resulting in a porous weld joint. The oxide layer also must be removed within minutes of welding. You can use a stainless-steel wire wheel or muriatic acid. Remember that if the acid is strong enough to melt aluminum oxide, it can also melt you. Please don't taste it. Ultimately, TIG welding is the rarest form of welding and is the most common style that the hobbyist abandons. Once you understand the chemistry and physics at play, creating a good TIG weld ceases to resemble a superstitious ritual and begins to make sense.
Tension:
The final point to cover is heat. The metal expands and contacts with heat. Each alloy demonstrates different characteristics such that the amount of expansion varies. The process and timing used to apply the welds are equally essential as the above factors. If you were to weld the entire side of a gate without match-welding the other side before it cools, you would have a potato-chip-looking structure. With a flat plate, the effect of warping is even more acute. The industry employs stud welds, stitch-cooling styles, and many other methods to control heat flow through metal. The difficulty of heat expansion and contraction can also be a value in the design side. Resonant frequency seems like an unlikely gremlin to deal with in iron gates and fences, but in areas of high sustained winds, the vibrations can tear your art to the ground. Recall earlier that I had mentioned how the weld line tempers the metal immediately adjacent to it. When harmonic vibrations get going, they slowly fracture near each weld. The joints are fracturing everywhere within a year or two because of the wind. I learned this first-hand from one of my gates and have developed the habit of designing tension into my designs. This process starts with choosing the proper dimension steel that is strong enough and welding and intentionally overheating on one side, followed by a light weld to the other side; this would cause a warp if I had not done the opposite weld on the next piece. This process of tension and reverse tension allows me to have long sections of steel that will resist harmonic vibrations. Once you get the hang of it, you find the metal sounds different when tapping the bars.
Conclusion:
Our modern world and infrastructure would not exist without the welded joint. Before the dawn of the 19th century, metals could only be joined through rivets, and before that, we were not using steel in a way that showcased its unique structural prowess. My welding journey is one skill followed by iterative years of mistakes and solutions. As time progressed, my career as a Hazmat Technician prompted a more metallurgical and precise view of my age-old talent. Skill-developed knowledge has culminated in mastery.