It is known that 3D printing makes manufacturing a lot easier and more precise than traditional manufacturing methods such as molding or machining. Some printers can 3D print using metals and alloys, but every technology has limitations. Can a fully functional engine be manufactured using a 3D printer?
As there are different types of engines and the requirements of each machine are different, there is no clear-cut answer to this question. However, let’s look into the facts and try to understand the elements that need to be gauged.
What is an engine?
In most cases, engines are made to convert chemical energy from fuel or batteries into mechanical energy (motion). Although the terms “engine” and “motor” are frequently used interchangeably, there is a difference between the two in that motors run on electrical energy, and engines run on the combustion of fuels. In addition, there are several varieties, including heat, electrical, and response engines. The internal combustion engine is one of the most often utilized types of thermal devices. It converts fuel’s chemical energy into mechanical energy that can propel most vehicles, including larger machinery like trains and airplanes, and it can also be used to produce electricity.
An internal combustion engine works in a very straightforward manner. First, fuel and air are combined after being removed from the atmosphere. In a gasoline-powered engine, the piston compresses the mixture of air and fuel, the spark plug ignites the mixture, and combustion occurs. The resultant explosion pressurizes the combustion chamber, forcing the piston to move forcefully, which rotates a crankshaft. The residual gases and particles are subsequently ejected from the chamber to be expelled through an exhaust system. The wheels of a car might be driven using this method, which requires the engine to rotate a crankshaft up to several thousand times each minute.
The functioning of a machine was explained here to put into perspective the conditions that prevail during the operation of a device and the wear and tear it could cause to the engine components. These factors determine what material needs to be used to build the instrument; knowing this would help understand whether engines could be 3D printed.
What are the components of an engine?
A basic engine would have the following components:
- Engine block or cylinder block: It is the principal framework on which the numerous elements are supported. A number of bolts and studs will be used to tighten this cylinder block with the cylinder head. Between the cylinder block and the head, a gasket will be used. Cooling fins are included on the cylinder block if an air conditioning system is used for engine cooling. Water jackets will be installed on the cylinder block walls if the system uses water cooling. The cylinder block will be cast as a single piece for multi-cylinder engines. The Crank Case is the term used to describe the Cylinder Block’s lower half. It will serve as the lubrication oil’s sump.
- Cylinder: A precise cylindrical shape cut into the cylinder block will allow the piston to reciprocate. It’s known as a cylinder. This container, filled with the working fluid, goes through many thermodynamic processes to generate work output.
- Piston: The piston is a cylindrical piece that fits into the cylinder and significantly impacts how the work is produced. With the aid of the lubricant and the piston rings, it creates a gas-tight area that serves as the movable boundary of the combustion system. Piston rings are inserted into the piston’s slots to create a tight seal between the piston and the cylinder.
- Spark plug: It is the part that initiates the combustion process in the spark ignition system. The spark plug will be located in the Cylinder Head. Spark plugs are only found in spark ignition engines.
- Combustion chamber: The combustion chamber is the area between the piston’s top and the cylinder’s upper portion. The combustion chamber serves as the location for fuel combustion. Pressure is increased in the cylinder as a result of fuel combustion, which releases heat energy.
- Connecting rods: They link the crankshaft and the piston. The small end of the connecting rod, which is attached to the piston side by a gudgeon pin, is one end of the rod. The big end, or opposite end, of the connecting rod, is joined to the crankshaft by a crank pin.
- Crankshaft: The output shaft’s crankshaft transforms the piston’s reciprocating action into rotary motion. On the crankshafts, there are balance weights available for the rotational system’s dynamic balancing.
- Inlet manifold: Inlet manifold refers to the conduit that joins the engine’s inlet valve to the intake system. The air and fuel mixture are taken directly into the cylinder.
- Exhaust manifold: The exhaust manifold is the conduit that joins the engine’s exhaust valve to the exhaust system. The combustion byproducts will escape into the atmosphere through the exhaust manifold.
- Inlet and exhaust valves: A valve is a mechanism that solely moves the fluid in one way. On the cylinder head or its side, inlet and exhaust valves control the charge entering the cylinder (inlet valve) or release the combustion byproducts from the cylinder (Exhaust Valve). If it is a 4-stroke engine, only valves will be accessible. For managing the charge entering the cylinder (the transfer port) or releasing the combustion products from the cylinder, there are ports accessible in two-stroke engines (Exhaust port).
What factors need to be considered before 3D printing an engine?
1. Software for 3D modeling: Many people today are familiar with the power and versatility of 3D model maker programs. These programs are useful in creating prototypes for various types of engines and other mechanical parts. By using 3D modeling software, you can quickly build a fully functioning engine from scratch, allowing you to experiment with different design concepts before moving on to more expensive prototypes or machine tools. Whether you are working independently or as part of a team project, this software provides an effective way to visualize your engine designs quickly and make any necessary adjustments before moving forward.
2. Type of engine: The type of engine is one of the most important considerations here. This is because the same components used for making a car engine cannot be used to create a jet engine. The pressure generated inside a car engine is much smaller than the pressure generated by a jet engine. This is why car engine components are made from cast iron or its alloys or even aluminum, whereas jet engine components are made from stronger alloys such as alloys of titanium. While cast iron melts at about 2200 degrees Fahrenheit, titanium melts at 3034 degrees Fahrenheit. The 3D printer required for both engines would not only need different power requirements but would also require different-sized printing areas. These would also cause dramatic changes in the costs involved in terms of initial investment as well as operational costs.
3. The material used: If the user is making a model engine to demonstrate the way an engine looks or functions, they could print it using anything, even plastics, as long as no combustion is taking place in it. Even functional models that use internal combustion needs to be made from materials that can withstand the heat and pressure generated while the fuel burns and causes the pistons to move. Besides, not all materials can be printed using the same 3D printer. Different materials have different melting points and therefore require different temperatures, costs, and even different safety measures for operation.
4. Intended use: The intended use of an engine made with 3D printers is another crucial factor. If it is just a model and only serves the purpose of being a visual representation of what an engine looks like, any 3D printer can be used, as the model just has to be made according to scale and does not have to have the dimensions of an actual engine. Also, it can be printed using plastics or resins and painted to look like an engine. Even models with moving parts can be 3D printed using plastics as long as the combustion of fuels does not power the movement; electric motors can be used to turn the crankshaft, or they can be rotated manually so that they can demonstrate the working of an engine. However, if the intended use of the machine is to power a vehicle through internal combustion or electricity, the material used must be able to withstand the operating conditions of locomotion.
5. Manufacturing time: The estimated manufacturing time for a car engine block would theoretically go up to a maximum of 10 hours, including the time for preparing the mold, cooling the molten metal, reclaiming the mold components and machining excess parts, a mass production plant for engines could manufacture several machines in a single shift this way through injection molding. However, 3D printing a single car engine block could take up to 300 hours. Therefore 3D printing an engine is not the best option if mass production is not the intended purpose. Besides, the bigger the size, the longer it takes to print an object with a 3D printer. Moreover, engines have different components, and mass production of these multiple parts with a single or limited number of 3D printers is a prolonged process.
In conclusion, 3D printing an engine is not impossible, but information about the components of an engine and the conditions in which they have to operate makes it clear that 3D printing these components is a costly affair. Apart from the cost involved, it is a slow process. Therefore 3D printing an engine depends on the intended use and the type of engine.