ADDITIVE MANUFACTURING
ALUMINIUM ALTERNATIVES
Why machine shops are 3D printing jigs and fi xtures, and how they are tough enough to do the job
I
n the past aluminium has often been the material of choice for prototypes, jigs and fi xtures, and welding fi xtures due to its low
cost, ready availability and ease of machining. However, when you take into consideration the associated tooling costs, set up and manpower required it can often make low volume or complex machining using aluminium too expensive. Now that 3D printing has matured,
it is widespread and has many applications across all industries. Not all 3D printers are made the same though; there is huge variation in the technologies used. Some rapidly print plastics for prototyping, others use UV light to solidify resin to micron accuracy, and others use lasers to directly sinter metal powder. These are just a few examples, and there are dozens more with diff erent pros and cons. No one 3D printer can do everything, so it’s important to choose the right technology. Strength has long been a challenge in 3D printing, however, as a result of material properties. To extrude a material from a nozzle it typically has to be brought near to melting point. This can be achieved with plastics, but metals require other methods (though there are ways of extruding metal fi lament without extreme heat). Very often, materials that can be easily melted and shaped do not have the best strength characteristics.
Composites are the solution to
this problem, and Markforged has developed unique continuous fi bre reinforcement (CFR) technology into its 3D printers to make it a reality. A secondary nozzle extrudes and cuts to measure a second continuous material, such as carbon fi bre, Kevlar, or fi breglass. This continuous fi bre is “ironed” into the base material, and the resulting parts have a better strength to weight ratio than aluminium. These materials are less costly than
aluminium, and manufacturing the parts in house overnight eliminates the costs and lead times associated with outsourcing. These factors make 3D printed parts an attractive alternative to aluminium. In machine shops there is an additional challenge in the form of coolant, which can quickly corrode aluminium and other metals. Because the basic Markforged fi lament materials are nylon based,
they have excellent chemical resistance properties that allow them to survive coolant in CNC machines. In a case study with DANA
Incorporated, 3D printing workholding fi xtures and die sets with Markforged reduced the cost of the company’s tooling by 70%, and reduced lead times by 90% in factories across seven countries. In another example, ISS Aerospace used Markforged’s 3D printers from Mark3D to create carbon-fi bre reinforced UAV and drone parts that are lighter and stronger than aluminium. With the ability to rapidly replace damaged parts and create one-off designs, ISS Aerospace has built a strong aerospace business based on 3D Printing.
Oliver Partridge is at Mark3D.
www.mark3d.co.uk
3D Printed brake levers showing internal continuous Kevlar and fi breglass fi bres
Markforged FX10 Industrial 3D Printer with a completed part on the print bed
14
www.engineerlive.com
ISS Aerospace Sensus L 3D printed UAV
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48
