A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Gurumurthy, T.
- Critical Aspects in Propellant Mixer Development
Authors
1 C M T I, Bangalore, IN
Source
Manufacturing Technology Today, Vol 7, No 11 (2008), Pagination: 12-14Abstract
Mixer is versatile equipment, finding application in diverse fields ranging from Household, Food, Pharmaceuticals, Chemical, Personal care industries, Construction, Rocket Propellant application and many others. To suit the requirement of individual applications, Mixers have been developed with different design philosophies-(a) horizontal and vertical versions with (b) single, dual, three and four blade configurations and (c) with and without planetary motion to the agitator system. Some mixers are of fixed bowl (Mix container) construction and some are rotating bowl type.... For Rocket propellant applications, considerations like stringent requirements of homogeneity and consistency of the product mix as well as the operational safety drive the choices in the Design Philosophy and various features. This paper attempts to focus on some of the salient features of the Solid propellant Mixers developed at CMTI.
- Reverse Engineering
Authors
1 Central Manufacturing Technology Institute, Bangalore, IN
Source
Manufacturing Technology Today, Vol 1, No 10-12 (2002), Pagination: 3-6Abstract
Reverse Engineering by scanning could be used to reproduce apart without the aid of drawings or design data in a very short time. The surface data of the model is captured using scanning devices and the data so collected is used to build a model for generating machining programs. In case the part has to be molded, the model data could be used to manufacture the mold cavity directly The captured data could also be converted into an STL file for Rapid Prototyping. Digitizing is a very useful method because:
- Very complex mold shapes that cannot be produced cost-effectively by CAD /CAM can be digitized and directly machined on CNC machine by creating CNC program on the digitizing system.
- Die modification made during die try out can be captured and read into the database.
- In some cases, the physical model (old part/die/mold) may be available for which the CAD model would be costly to develop.
- Digitizing can be done unattended through auto scan softw are feature.
- Digitized data can be transferred, modified, converted (from core to cavity mirrored or scaled), and used for accurate and high-speed NC machining, as well as for geometric quality control on a CMM.
- In some cases, design/drawing of the part or mold is not available and required to generate the same using CAD/CAM.
The most accurate and widely used method o f digitizing is contact tracing, in that the probe operates with constant against the model. The probe movement or scanning methods are decided by the software.
There are noncontact type scanning systems available for some specific applications. This scanning process can be conducted unattended, with typical feed rates of 1000 mm/min to 5000 mm/min. Laser digitizing with a multi-axis laser head is a relatively new technique that can obtain geometric data more quickly and with sufficient accuracy for application.
- Design of Prototypes & Injection Mould Tooling for Manufacturing by Direct Metal Laser Sintering (DMLS) Technology
Authors
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore-560 022, IN
Source
Manufacturing Technology Today, Vol 1, No 3 (2002), Pagination: 5-9Abstract
Generally, Prototypes & injection mould toolings are produced by conventional, Computer Numerical Control (CNC) machining & electrical discharge machining processes. Making moulds by these methods is slow and expensive for low batch quantities. Product complexity is increasing & product cycles are growing ever shorter Therefore Rapid Prototyping (RP) tooling fabrications should be considered for projects in which the reduction of time to market is important, for prototypes and short to medium volume production runs.
At least six different Rapid Prototyping technologies are commercially available in the market. Direct Metal Laser Sintering (DMLS) is one such Rapid Prototyping technology for producing prototypes & toolings for injection moulding & investment casting processes using metal powder (Bronze Nickel). EOSINT M250 machine from M/s EOS Gmbh-Germany is a direct metal laser-sintering machine.
Each manufacturing process has its advantages and limitations from the point of accuracy, shape, surface finish & cost. This paper deals with the brief description of EOSINT M250 RP machine, process, design rules for parts, accuracy surface finish & geometry of parts that are best suited for DMLS technology from the point of cost and time.