3D printing, as an additive process, offers much more than traditional machining techniques in terms of achievable complexity of a model shape.
That fact was a motivation to adapt discussed technology as a method for creating objects purposed for aerodynamic testing.
The following paper provides an overview of various 3D printing techniques. Four models of a standard NACA 0018 aerofoil were manufactured in different materials and methods: MultiJet Modelling (MJM), Selective Laser Sintering (SLS) and Fused Deposition Modeling (FDM).
Various parameters of the models have been included in the analysis: surface roughness, strength, details quality, surface imperfections and irregularities as well as thermal properties.
Follow established procedures, assembly documentation, work instructions, methods and sequence of operation related to the creation of production parts and tooling using Additive Manufacturing (AM) (3D Printing), FDM and SLS techniques.
Essential Functions
Setup, operate and perform daily maintenance on AM machines.
Desirable Qualifications
Background in FDM (Fused Deposition Modeling) and/or Selective Laser Sintering (SLS) AM technologies.
Unmanned Aerial Vehicle (UAV) platforms are of major interest to Defense, Government, and commercial industries. The ability to remotely control an aerial vehicle capable of surveillance, offensive and defensive maneuvering, reconnaissance, or numerous other applications without the need to put a human life in jeopardy is a major attraction to their use. Furthermore, there exists opportunities to make these airborne vehicles largely autonomous, further reducing the need for even remote human operators. However, for all of the significant advantages of UAVs, there is a significant negative: the cost of manufacture, and the cost of design. Due in part to the substantial amount of complex electronic equipment on board, UAVs become not only a design of aeronautics, but an experiment in energy conservation through optimization. A limited range of UAV power becomes a limiting factor of UAV application. The challenge becomes to optimize the size, weight, and aerodynamics of the UAV based on the application.
"Manufactura Aditiva" es hoy día el término más comunmente aceptado en entornos profesionales para referirse al conjunto de tecnologías de fabricación basadas en la disposición sucesiva de capas de material.
Un conjunto de tecnologías en pleno desarrollo que está permitiendo obtener nuevos diseños de UAVs a unos costes y en unos plazos de tiempo imposibles de obtener mediante la manufactura tradicional. Vamos a ver en este post las tecnologías más significativas que existen a día de hoy.
A grandes rasgos, existen tres tecnologías que dominan el mercado:
FDM (Acrónimo de Fused Deposition Modeling o Modelado por Deposición de material Fundido)
SLA (Acronimo de Stereolitography o Estereolitografía)
SLS (Acrónimo de Selective Laser Sintering o Sinterizado Selectivo por Laser)
La tecnología FDM utiliza un cabezal de extrusión para depositar filamentos de plástico en estado de cuasi-fusion. Es la tecnología más extendida a escala mundial, y su rango de precios para aplicaciones profesionales empieza en torno a 15.000 Euros, pudiendo alcanzar hasta 300.000 en función de las capacidades de la máquina.
La tecnología SLA utiliza un láser UV para polimerizar en determinadas zonas una fina capa de un monomero fotosensible.
La tecnología SLS utiliza un láser infrarrojo para sinterizar en determinadas zonas una fina capa de polvo termoplástico.
Cada tecnología tiene sus propias ventajas y desventajas respecto de las otras, y elegir una u otra es el resultado de una ecuación que puede contener muchas variables: Para fabricar una sola pieza indudablemente la opción más económica será la FDM, pero si necesitamos fabricar grandes cantidades de piezas todos los días quizá sea mejor optar por la tecnología SLS.
En lo referente a la libertad de diseño, es cierto que la Manufactura Aditiva permite obtener diseños imposibles de fabricar mediante las tecnicas de mecanizado tradicional. Pero existen algunas limitaciones a tener en cuenta. Por ejemplo, tanto la FDM como la SLA requieren el uso de estructuras de soporte para construir superficies por debajo de un angulo crítico relativo a la superficie de fabricación (normalmente 45º) y esas estructuras de soporte deben ser eliminadas tras la fabricación, lo cual requiere sumergir durante unas horas la pieza en un baño de disolución (caso de FDM) o someterla a otro tipo de procesos (caso de SLA).
Si optamos por la SLS no tendremos que esperar a que se disuelva el material de soporte pero necesitaremos eliminar a mano el polvo sobrante, además de que tendremos que esperar varias horas de enfriamiento antes de abrir el horno para retirar la pieza, ya que de lo contrario ésta podría sufrir deformaciones por el cambio brusco de temperatura.
Los materiales disponibles tambien difieren para cada proceso, aunque los fabricantes de UAVs optan preferentemente por el FDM ya que ofrece la posibilidad de trabajar con diferentes termoplásticos, entre los que se incluyen el ABS, el Policarbonato, el Nylon, la Polifenilsulfona y la Polieterimida, lo cual les proporciona un amplio abanico de aplicaciones que pueden ir desde el modelado conceptual y el prototipado funcional, hasta la fabricación digital directa de piezas aptas para uso final.
En particular, los materiales basados en Polieterimidas ofrecen una alta resistencia térmica y química, lo cual los convierte en los favoritos para la fabricación de piezas que deban resistir el contacto con el fuego.
In the growing unmanned vehicle market there is increasing demand for technologies that reduce time-to-market and lower development costs.
Until recently, most of UAV OEMs had been using various production techniques, such as CNC milling, mainly in the production of the aluminum core of its products.
This had become problematic on three levels:
•First, costs to produce increasingly complex and sophisticated parts were rising exponentially using traditional processes, such as CNC machining.
•Second, there was a critical dependency on sub-suppliers of CNC milled parts which tended to prioritize high volume contracts giving smaller orders a slower turn around.
•Third, some parts must be custom, meaning the company was producing even lower volumes with resultant increased cost for these parts.
To solve these issues, many UAV design engineers are reviewing various alternative technologies for more efficient production combining traditional production methods with modern in-house production techniques such as Fused Deposition Modeling (FDM), that allows delivering of custom parts just in hours or days.
Replacing expensive and lead-time critical CNC-milled parts with in-house manufactured plastic parts, engineers are reducing the part cost to one third. Also, the plastic parts perform better technically, weighing less and providing better electrical insulation.
Stratasys and Optomec Inc. announced that the companies successfully completed a joint development project to merge 3D printing and printed electronics to create the world’s first fully printed electro-mechanical structure.
The development of a “smart wing” for an Unmanned Aerial Vehicle (UAV) model with functional electronics is a revolutionary event that has the potential to change product development in industries including medical device, consumer electronics, automotive and aerospace. An Optomec Aerosol Jet system was used to print a conformal sensor, antenna and circuitry directly onto the wing of a UAV model. The wing itself was 3D printed with the Stratasys Fused Deposition Modeling (FDM) process. The electrical and sensor designs were provided by Aurora Flight Sciences, a supplier of UAVs. The combination of FDM 3D printing and printed electronics technologies can provide benefits over traditional prototyping, manufacturing and field repair processes. Performance and functionality of products can be improved in two ways: 3D printers enable lighter weight mechanical structures; and conformal electronics printed directly onto the structure frees up space for additional payload. In turn, the process has a positive impact on the environment by using fewer materials. Manufacturers can implement this technology in a multitude of applications, not just in aerospace. This technology can benefit numerous industries by allowing thinner, lighter, fully functional structures that cost less to manufacture.
A team of engineers from the AMRC’s new Design & Prototyping Group (DPG) have designed, manufactured and flight tested a UAV built entirely of ABS plastic, using FDM (Fused Deposition Modeling) technology.
The recent increase in the use of both additive layer manufacturing and UAVs has led to the availability of a number of 3D printed UAVs for a range of applications. For printing relatively large components such as a UAV airframe, FDM technology is chosen over stereo lithography and selective laser sintering for its lower initial investment, material cost and simplified process.
The manufacturing aspects of the project were led by Additive Manufacture Development Engineer Mark Cocking: “All parts required for the airframe can be combined onto a single build within the Fortus 900 machine, taking less than 24 hours with ABS-M30 material. Before design for additive manufacture optimisation, this airframe would take over 120 hours to produce.”
Just a sort of amazing pictures of the 3D-PrintedQuadCopter 2.0 of Mike Bristol. As you will note, the technology used was FDM (Fused Deposition Modeling) (Read more)
UAV Solutions Inc. in Jessup, Maryland, specializes in UAVs (Unmanned Aerial Vehicles) and UAV control systems.
The video above includes a flight demonstration of a UAV that was manufactured using StratasysFortus 400mc Production Systems. Typical applications of this vehicle include use by police departments, fire departments, and other emergency first responders, as well as military applications. According to company CEO Bill Davidson, when the company bought their first Stratasys3D Printer, they thought that it was an impressive technology – but they didn’t really understand all that it could do.
While they originally figured they would use it to produce little prototypes or giveaways for their customers, FDM-based (Fused Deposition Modeling) 3D printing has now “crept” into every aspect of their manufacturing process. In particular, they found that the ULTEM™ 9085 resin material is particularly well-suited to aviation applications.
As flame retardant high performance material, ULTEM exhibits a high strength-to-weight ratio and FST (flame, smoke, and toxicity) rating which make it an excellent choice for the commercial transportation industry – especially aerospace, marine and ground vehicles. The FDM-based manufacturing process allows UAV Solutions to very rapidly make changes to the avionic structures, thereby enabling them to meet the high performance and precise demands of their customers. In fact, Davidson states that using the ULTEM 9085 allows them to manufacture components that could not be made with standard milling procedures.
