Archive for November 2012

Industrial Management Notes

November 11, 2012


Important machines

November 11, 2012

centrifugal pump

Differential gearbox

F1 Piston and connecting rod

heat exchangers


worm and worm gear

Old question papers

November 11, 2012


November 10, 2012




some important basics required to study Fluid Mechanics

November 10, 2012
  1. fluid_pr
  2. conmass
  3. integral_equations
  4. non-dimensional-numbers
  5. streamlines

TechJect’s Dragonfly micro UAV flies like a bird and hovers like an insect

November 7, 2012
The TechJect Dragonfly fits in the palm of a hand

The TechJect Dragonfly fits in the palm of a hand

Given their impressive flight capabilities, it’s not surprising to see researchers turning to the world of flying insects for inspiration when developing new kinds of micro UAVs. With their ability to both fly at high speeds and hover, the dragonfly would seem an obvious candidate for biomimicry, but we hadn’t seen any attempts to model a micro UAV on the dragonfly’s four wing design – until now. A multi-disciplinary team from Georgia Tech has developed a robotic four-winged ornithopter called the TechJect Dragonfly that fits in the palm of a hand and combines the flight capabilities of a quadricopter, helicopter and fixed wing aircraft in one.

The TechJect Dragonfly is the culmination of four years of research and development at Georgia Tech, assisted by US$1 million in funding from the U.S. Air Force. TechJect is a spinoff out of Georgia Tech’s Robotics & Intelligent Machines (RIM) Department that was created to bring the Dragonfly and other robotic flyers to market. To that end, the TechJect team has turned to crowdfunding site indiegogo to help get the Dragonfly off the ground.

As well as borrowing its wing design from its biological namesake, the Dragonfly is also similar in size, measuring 15 cm (6 in) long. It weighs around 25 g (0.88 oz) and is powered by a 250 mAh lithium polymer battery that provides hover times of 8-10 minutes and a hybrid (hover/flight) time of 25 to 30 minutes.

The Dragonfly features a four-wing design

Designed with a focus on modular customization, the Dragonfly carries up to 20 onboard sensors to suit a variety of applications, from aerial photography, gaming, research and development, civilian security and military reconnaissance. The modular approach results in the availability of various flight control packages.

Alpha model

The Alpha model, which can be secured with a US$99 pledge (provided the funding goal is met) but is estimated to retail at $250 or more, comes with a MARC-Basic flight computer, solenoidal actuators, and flight accessories including a remote controller, battery and charger.

The Alpha model Dragonfly

Delta model

The Delta model has the same MARC-Basic flight computer and flight accessories, but the solenoidal actuators are replaced with a continuously variable transmission (CVT), which improves performance, particularly in terms of hovering. A spare set of wings is also included. The Delta can be had for a pledge of $179, with the retail price estimated to be around $500.

The Delta model Dragonfly

Gamma model

Aimed at R & D, prototyping and programming applications, the Gamma model sees the flight computer upgraded to the MARC-2 and adds a camera and Wi-Fi, so it can be controlled via a computer, iPhone or Android smartphone.

The Gamma model Dragonfly

The CVT found on the Delta also features on the Gamma, and the same flight accessories, along with a spare set of wings are also included. A pledge of $249 will secure the Gamma model, which is expected to retail for $750.

Omega model

The top line model is the Omega, which is powered by a more powerful MARC-3 flight computer that boasts 20 onboard sensors (including two cameras), and features a CVT and Wi-Fi. The familiar flight accessories and an extra set of wings are also included. The Omega requires a pledge of $399, with an expected price of $1,499 at retail.

The Omega model Dragonfly

All models are offered in blue, green, yellow, orange, red, black, white and silver color options and come with a fully customizable software development kit (SDK) for the creation of custom applications. However, TechJect will offer a number of free apps for iOS and Android devices and PCs. There will also be an online forum where users can share their custom apps and get development help from the TechJect team.

The Dragonfly’s modular construction also allows the future upgrade of various components, such as the wings, actuators, and onboard electronics. These will be available through the TechJect website.

TechJect is looking to raise $110,000 via indigogo by the time the calendar ticks over to 2013. If it achieves its goal, TechJect aims to be delivering Dragonflies to pledge-makers from July, 2013.

The TechJect team gives an overview of the Dragonfly in the video below.

Source: indiegogo via TechJect

Man to climb Chicago’s Willis Tower using thought-controlled bionic leg

November 3, 2012
Zac Vawter prepares for 'SkyRise Chicago', a fundraiser for the Rehabilitation Institute o...

Zac Vawter prepares for ‘SkyRise Chicago’, a fundraiser for the Rehabilitation Institute of Chicago

Despite losing most of his right leg in a motorcycle accident, Zac Vawter (31) intends to climb all 103 flights of stairs at Chicago’s Willis Tower this Sunday. He’s been helping researchers at the Rehabilitation Institute of Chicago (RIC) test a cutting-edge bionic leg that is controlled by his own nerve impulses. He can walk, kick a ball, and climb stairs by simply thinking of what he wants his leg to do.

Zac Vawter will climb all 103 flights of stairs at Chicago's Willis Tower with the help of...

Prosthetic legs are divided into three categories: Conventional feet, energy storing-and-returning (ESR) feet, and bionic feet. Conventional feet aren’t much better than early wooden legs, making them uncomfortable and the least natural. ESR feet, like the recently unveiled AMP-Foot 2.0, use springs (and sometimes actuators) to assist with walking, so that the user doesn’t have to waste energy compensating for their prosthesis. Bionics take ESR technology to the next level by allowing the user to control the limb with their own nervous signals.

The U.S. Department of Defense is investing US$8 million dollars to develop a functional b...

When Vawter’s leg was amputated, a surgeon prepared him for a bionic leg by attaching nerves from his lower leg to his hamstring in a procedure called Targeted Muscle Reinnervation (TMC). RIC pioneered the procedure and developed a bionic arm back in 2005 for upper-arm amputees that, like the bionic leg developed at Vanderbilt University, can be controlled through nerve impulses detected by a series of electrodes attached to the skin.

For the time being, the bionic leg is an US$8 million dollar research project funded by the U.S. Department of Defense, but the goal is to build a commercial prosthesis that will dramatically improve lives. Researchers at Vanderbilt are collaborating with labs at MIT, the University of Rhode Island, and the University of New Brunswick to bridge the gap.

Zac Vawter (second from right) surrounded by researchers at the Rehabilitation Institute o...

The climb, which will help raise funding for RIC, is expected to take Vawter about an hour with a battery change or two along the way. He wants to help raise public awareness for the RIC, which has already outfitted more than 50 patients, including U.S. service members who have lost limbs in combat, with the institute’s bionic arm.

The bionic leg can be seen in action in the video below.


Source: Rehabilitation Institute of Chicago