Ever since the Venice Arsenal started mass producing ships in what some refer to as the world’s first factory back in the 13th century, manufacturers have been driven by the need for speed. Manufacturing speed, that is.
In today’s environment where consumers demand for new products is driving ever shorter product life cycles, manufacturers are consistently looking to turn and produce products at ever increasing speeds just to remain competitive. Superior quality and a low price are a given for companies just to be in the race. What differentiates the winner in this new manufacturing competition is the ability to react quickly, produce fast and deliver even faster.
From mobile phones to home computers to automobiles, new designs, improvements, and consumer whims are forcing companies to make rapid adjustments to their manufacturing process to remain in the game. How many cell phones have you owned over the past decade? How many variations of computers? The constantly changing global marketplace is driving companies to maximize productivity and quality at the lowest cost and they must do it faster than the competition. They are asking themselves how fast can we deliver and how fast can we design the next generation of product? Speed is today’s new competitive advantage.
It doesn’t take a leap of faith or a calculator to conclude that the higher your production rate, the lower your cost per unit will be. After all if you can make twice as many widgets as your competitor in the same amount of time, your advantage is obvious. Speed remains an automation customer’s most pressing requirement today.
Manufacturers looking to increase production speeds naturally look to automation to eliminate the tedious, slow, and repetitive processes on the production line. Robots can increase manufacturer’s production. SCARA, six-axis, and Delta robots are commonly used in high speed manufacturing.
Many have adopted the use of Delta robots whose multi arm design is particularly well suited for manipulating objects at a very high speed. The Delta robot (a parallel arm robot) was invented in the early 1980s by Reymond Clavel at the Ecole Polytechnique Federale de Lausanne in Switzerland. The purpose of the Delta robot was to manipulate light and small objects at very high speeds. In 1987, the company Demaurex purchased a license for the Delta robot and started the production of Delta robots for the packaging industry. Originally, the Delta robot was patented, and as a result, sources for them were limited to three companies: Demaurex SA (the original patent holder), SIG pack, and ABB Flexible Automation. However, that patent expired at the end of 2007.
Delta robots are a type of parallel robot, a robot where the end effector is connected to the base by multiple kinematic chains. Typically consisting of three arms connected to a universal joint at the base, a delta robot uses parallelograms in the arms to maintain the orientation of the end effector. Parallelograms restrict the movement to the X,Y, or Z direction. Because the actuators are in the base, and the arms are made of lightweight composite materials, these robots can reach extremely high speeds. This makes them very popular in picking and packaging. Delta robots can execute up to approximately 150 picks per minute. The robot's base is mounted above the workspace. From the base, three middle jointed arms extend. The ends of the three arms are connected to a small triangular platform. Actuation of the input links will move the triangular platform in the X, Y or Z direction. From the base, a fourth leg extends to the middle of the triangular platform to give the end effector a fourth rotational degree of freedom.
What if you’re looking for that next step? You need twice the productivity out of the same amount of factory space. What if you wish to pick parts from a moving conveyor belt at more than 150 parts per minute?
Currently the fastest Delta robot available (twice as fast as conventional robots) comes from Adept Technology, Inc of Livermore, California. The Adept Quattro s650 parallel robot is specifically designed for high-speed manufacturing, packaging, material handling, and assembly. It is the only robot in the world that features a unique four-arm rotational platform designed for maximum speed, maximum acceleration, and exceptional performance across the entire work envelope. Additionally, the powerful embedded amplifiers and compact controls make installation easy and enable saved workspace. The Adept Quattro robot offers major advantages over the traditional three arm Delta style kinematic. Using four arms instead of three results in faster cycle times and better payloads than traditional three arm delta robots. With four arms you get rotation rather than having to have an extra telescoping joint as is required on traditional robots. Featuring integrated vision and tracking, the Quattro robot can pick parts from a moving conveyor belt at the rate of up to 180 parts per minute. The Quattro robot typically mounts on a rigid overhead frame above the conveyor, and uses its integrated vision system to locate the parts.
What about cost? Delta robots typically run more than conventional SCARA and six-axis robots. How does that factor in to cost per placement?
Using the Adept Quattro robot as an example, the robot unit itself costs twice as much as a conventional SCARA or six-axis robot however it delivers twice the throughput. Since integration costs are the same the difference in the total installed cost is equal to the difference in robot cost, however you get twice the throughput. So in the example below, for the extra $25,000 extra you get twice the throughput. When you calculate out the cost per part a conventional robot system cost 1.714 times as much per part as a Quattro system. Plus, Quattro produces 24,480,000 parts over two years out of the same amount of factory space. In many factories, fixed expenses can represent 10-15% of the total product costs, and since they are fixed you can spread them over all this extra volume giving even more savings.
Manufacturers who want to remain competitive need to consider the avenues that will allow them to increase production and production speed. Delta robots specifically designed to meet that challenge may be the best option for companies wanting to keep ahead of the pack.