Friday, March 25, 2016

Recent - Latest Trends in Machining and Machine Tools

April 2016
Entry from a textbook

High Speed machining or cutting is defined as the cutting speed above which shear localization develops completely in the primary shear zone.

600 to 1,800 metres/minute is termed HSM.
1,800 to 18,000 metres/minute is termed Very high speed machining
Above 18,000 metres/minute it is termed ultra HSM

In the case of difficult to machine materials, High throughput machining is used.

Fundamentals of Machining Processes: Conventional and Nonconventional Processes, Second Edition
Hassan Abdel-Gawad El-Hofy
CRC Press, 06-Aug-2013 - Technology & Engineering - 562 pages

Google Book link

March 2016

Generally, the wheel velocity between 30 and 35 m/s is defined as conventional grinding;
The wheel speed exceeding 45 to 50 m/s is defined as high speed grinding;
The wheel speed between 150 and 180 m/s or higher is defined as Super-high Speed Grinding.

Volkswagen Group China applied the high speed grinding technique to grind engine camshafts. The wheel rotation-velocity is 4300 r/min, and 3000 workpieces can be ground each wheel dressing.

High Speed Grinding of Rails

Cecimo Magazine Summer 2011

Cecimo Magazine Winter 2011

New Trends in Production Systems Design and Operation

Trends in Recent Machine Tool Technologies - Dr. Toshimichi Miriwaki - Kobe University

Next Generation Grinding Machines

Updated 25 Mar 2016, 24 Feb 2012

Friday, March 18, 2016

Methods of 3D Printing - Rapid Prototyping and Manufacturing


The term “stereolithography” was coined in 1986 by Chuck Hull. Chuck Hull patented stereolithography as a method of creating 3D objects by successively "printing" thin layers of an object using a medium curable by ultraviolet light, starting from the bottom layer to the top layer. Hull's patent described a concentrated beam of ultraviolet light focused onto the surface of a vat filled with a liquid photopolymer. The UV light beam is focused onto the surface of the liquid photopolymer, creating each layer of the desired 3D object by means of crosslinking (or degrading a polymer). In 1986, Hull founded the world's first 3D printing company, 3D Systems Inc. It  is currently based in Rock Hill, SC. Stereolithography had success in the automotive industry. The technology continues to find innovative uses in countless fields of study.

Stereolithography works by focusing an ultraviolet (UV) laser on to a vat of photopolymer resin. With the help of computer aided manufacturing or computer aided design software (CAM/CAD), the UV laser is used to draw a pre-programmed design or shape on to the surface of the photopolymer vat. Because photopolymers are photosensitive under ultraviolet light, the resin is solidified and forms a single layer of the desired 3D object. This process is repeated for each layer of the design until the 3D object is complete.

• Digital Light Processing

The digital micromirror device (DMD) found at the core of DLP technology enables companies to develop uniquely fast and accurate 3D printers. These printers make use of liquid photopolymer resins to build objects. For each crosssectional slice of the object, the DMD projects patterned light
that selectively exposes and hardens the resin. Because an entire layer is exposed with a single pattern, fast build speeds are achieved independent of layer complexity. Projection optics can also be used to control the resolution on the image plane and adjust the layer thickness, leading to smooth and accurate finished parts. These benefits, combined with its proven reliability, make DLP technology the ideal solution for 3D printing systems.

• Inkjetted photopolymers
• Thermoplastic extrusion
• Selective Laser Sintering of plastics
• Selective Laser Melting of metals
• Blown metal powder • Welding
• Sand binding
• Binder jetted into metal powder (by ExOne)
• Smooth Curvature Printing (by Solidscape)
• Selective Deposition Lamination (by Mcor Technologies)
• Hybrid CNC

Thursday, March 10, 2016

3D Printing Research & Development - 2016 Onwards


3D Printing of Graphene Aerogels

Published: 11 February 2016

Feb 2016

3D Systems Launches ProX DMP 320 for High Precision, High Throughput Direct Metal Printing
Leverages expertise in high volume metal additive manufacturing
Exchangeable print modules increase application versatility and productivity
Centralized maintenance management and serial manufacturing workflow support create operating cost advantages
Release Date:
Monday, January 4, 2016 - 09:00


GE  using 3-D printing to make jet parts.

The first GE jet engine that used  a 3-D-printed part is the GE90. In February 2015, the Federal Aviation Administration approved GE’s design modification to the housing that holds the T25 sensor on GE’s 90-94B engine. The sensor takes temperature and pressure measurements for the engine’s control system.  GE found that  ice buildup on the traditionally-manufactured housing containing the sensor  affecting the compressor’s long-term durability.

The company decided to redesign the sensor housing entirely and make it using  Additive manufacturing.

The nozzles was machined from 20 separate parts. Now each nozzle is one solid part, assembled by layering powdered metal melted and fused together with lasers. With 19 fuel nozzles per engine, it’s a substantial difference that helps to streamline the manufacturing and assembly process.

Now GE is in the process of retrofitting the new T25 sensor housings on 400 in-service 90-94B engines, which started commercial service in 1995 and were built for the Boeing 777 aircraft.


NIST Special Publication 1176
Costs and Cost Effectiveness of Additive Manufacturing
A Literature Review and Discussion
December 2014

If additive manufacturing has a saturation level between 5 % and 35 % of the relevant sectors, it is forecasted that it might reach 50 % of market potential between 2031 and 2038, while reaching near 100 % between 2058 and 2065. The industry would reach $50 billion between 2029 and 2031, while reaching $100 billion between 2031 and 2044.11

The total global revenue from additive manufacturing system sales was $502.5 million with U.S. revenue estimated at $323.6 million.

The additive systems are categorized into various different processes.
ASTM International Committee F42.91 on Additive Manufacturing Technologies has developed standard terminologies.
The following are the categories and their definitions from the ASTM F2792 standard:

Binder Jetting: This process uses liquid bonding agent deposited using an inkjet-print head to join powder materials in a powder bed.

Directed Energy Deposition: This process utilizes thermal energy, typically from a laser, to fuse materials by melting them as they are deposited.

Material Extrusion: These machines push material, typically a thermoplastic filament, through a nozzle onto a platform that moves in horizontal and vertical directions.

Material Jetting: This process, typically, utilizes a moving inkjet-print head to deposit material across a build area.
Powder Bed Fusion: This process uses thermal energy from a laser or electron beam to selectively fuse powder in a powder bed.

Sheet Lamination: This process uses sheets of material bonded to form a three-dimensional object.

Vat Photopolymerization: These machines selectively cure a liquid photopolymer in a vat using light.

Additive Manufacturing Research and Education
An NSF Additive Manufacturing Workshop Report  July 11 and 12, 2013



updated  10 Mar 2016, 18 Feb 2016

Thursday, March 3, 2016

3D Printing Evolution of Research, Theory, Invention, and Commercial Technology

In early days, 3D printing technologies were called Rapid Prototyping (RP) technologies as these processes were originally conceived as a fast and more cost-effective method for creating prototypes for product development within industry. The very first patent application for RP technology was filed by a Dr Kodama, in Japan, in May 1980. But, the full patent specification was subsequently not filed before the one year deadline after the application.

In 1986, the first patent was issued for stereolithography apparatus (SLA) to  Charles (Chuck) Hull, who first invented his SLA machine in 1983. Hull went on to co-found 3D Systems Corporation — one of the largest and most prolific organizations operating in the 3D printing sector today. 3D Systems’ first commercial RP system, the SLA-1, was introduced in 1987 and following rigorous testing the first of these system was sold in 1988.

In 1987, Carl Deckard, who was working at the University of Texas, filed a patent in the US for the Selective Laser Sintering (SLS) RP process. This patent was issued in 1989 and SLS was later licensed to DTM Inc, which was later acquired by 3D Systems. 1989 was also the year that Scott Crump, a co-founder of Stratasys Inc. filed a patent for Fused Deposition Modelling (FDM) — the proprietary technology that is still held by the company today.  It is also the process used by many of the entry-level machines, based on the open source RepRap model. The FDM patent was issued to Stratasys in 1992. In Europe, 1989 also saw the formation of EOS GmbH in Germany, founded by Hans Langer. After a dalliance with SL processes, EOS’ R&D focus was placed heavily on the laser sintering (LS) process. Today, the EOS systems are recognized around the world for their quality output for industrial prototyping and production applications of 3D printing. EOS sold its first ‘Stereos’ system in 1990. The company’s direct metal laser sintering (DMLS) process resulted from an initial project with a division of Electrolux Finland, and it  was later acquired by EOS.

Other 3D printing technologies and processes  emerging during these years were  Ballistic Particle Manufacturing (BPM) originally patented by William Masters, Laminated Object Manufacturing (LOM) originally patented by Michael Feygin, Solid Ground Curing (SGC) originally patented by Itzchak Pomerantz et al and ‘three dimensional printing’ (3DP) originally patented by Emanuel Sachs et al. Number of  companies entered the RP market but only three of the originals remain today — 3D Systems, EOS and Stratasys.

Further research and development in the area led to the emergence of new terminology, namely Rapid Tooling (RT), Rapid Casting and Rapid Manufacturing (RM).

In terms of commercial operations, Sanders Prototype (later Solidscape) and ZCorporation were set up in 1996, Arcam was established in 1997, Objet Geometries launched in 1998, MCP Technologies (an established vacuum casting OEM) introduced the SLM technology in 2000, EnvisionTec was founded in 2002, ExOne was established in 2005 as a spin-off from the Extrude Hone Corporation.
Sciaky Inc was pioneering its own additive process based on its proprietary electron beam welding technology. These  new companies increased number of units  operating across a global market. The  accepted umbrella term for all of the processes was Additive Manufacturing (AM).

The sector now  shows signs of distinct diversification. First, category was geared towards part production for high value, highly engineered, complex parts. The production applications are in the aerospace, automotive, medical and fine jewellery sectors. Years of R&D  are now paying off. The second category of the 3D printing system manufacturers were developing and advancing ‘concept modellers’. These were 3D printers have the focus on improving concept development and functional prototyping. But, that were being developed specifically as user-friendly, cost-effective systems.

Price Competition in 3D Printing Machines

In 2007, the market saw the first system under $10,000 from 3D Systems. The popular target at that time was to get a 3D printer under $5000 — this was seen by many industry insiders, users and commentators as the key to opening up 3D printing technology to a much wider audience.  As it turned out though, 2007 was actually the year that did mark the turning point for accessible 3D printing technology — even though few realized it at the time.  Dr Bowyer conceived the RepRap concept of an open source, self-replicating 3D printer as early as 2004. 2007 was the year the shoots started to show through and this embryonic, open source 3D printing movement started to gain visibility.

In  January 2009 that the first commercially available 3D printer – in kit form and based on the RepRap concept – was offered for sale. This was the BfB RapMan 3D printer.  It was closely followed by Makerbot Industries in April the same year. More commercial model are being made available.

2012 was the year that alternative 3D printing processes were introduced at the entry level of the market. The B9Creator (utilising DLP technology) came first in June, followed by the Form 1 (utilising stereolithography) in December. Both were launched via the funding site Kickstarter — and both enjoyed huge success.

In 2013, there was significant growth and consolidation in 3D printing industry. One of the most notable moves was the acquisition of Makerbot by Stratasys.

Heralded as the 2nd, 3rd and, sometimes even, 4th Industrial Revolution by some,  3D printing is having huge impact on the industrial sector.

22 Feb 2016
Metal 3D Printed Concept F1 Cylinder Head

3D Printer and 3D Printing - Related Patents

First Patent filed by Scott Crump in 1989

Updated 3 March 2016, 9 Feb 2016