A unique robot fettling cell has enabled a UK aluminium diecaster to reduce the real time of processing a casting through all the cutting, fettling, linishing etc. to drastically reduce the time it takes to get the castings out the door and to the customer.
Designed and built in-house, the robot fettling cell is now working on around 80 different components and has revolutionised work at Hall & Botterill Ltd of Leeds (UK). Such is the innovation that the company was recognised by its peers when it won the prestigious Company Innovation category at the Cast Metals Industry Awards Dinner in November 2016.
Hall & Botterill first investigated robotic fettling in 2005 but at that time the cost of investing in robots to meet the company’s specific needs was cost-prohibitive.
In 2012, the idea was re-visited as a way of separating production capability from the number of men employed. The rationale was not to reduce staff but to reduce the danger associated with fettling, and indeed to increase the working life of employees in that part of the company. Despite previous reservations about cost, the dream was about to become a reality. The company designed and built its own cell sourcing many different trades to help develop it, including the purchase of the correct tooling, which of course had to be robot compliant.
The rationale behind automation
Hall & Botterill manufactures a range of rainwater hopper heads and gutters and managing director Alex Paterson has long desired to create a way of casting gutters by automation to eliminate the need for members of the workforce having to lift very heavy, large ladles full of molten aluminium, twist, turn and pour into the die. This laborious and tiring job could inevitably cause neck and back strain.
A complex programming process
The robot arrived in June 2013 and programming began in August of the same year. The difference is that the robot is a multitasking machine, the aim being to take a casting from die to sale.
The programming task was at best complex because of problems with de-burring causing major issues, such as the tool digging in to the casting. However, within a month one component was programmed, followed by another, which didn’t require fine de-burring and would have been extremely dangerous to saw manually. Nobody seemed able to provide a solution to the digging in problem, until in August 2014, there was a random visit by a rep who suggested using a different cutter which would not bounce or dig in to the casting. Success!
Speaking about the investment Paterson said: “The robot is proving to be an indispensable member of the team!
“Everyone who has been or is still involved with our robot is convinced that it is unique and that they’ve never seen a robotic cell like it. We believe it is so different because, unlike the robots that are widely used in the automotive industry, it is a multitasking machine. Our robot picks up the casting from a turntable, carries it to the circular saw and then moves to the rough debur tool, then on to the linisher, followed by the fine debur and, if necessary, to the drill. The robot then drops the casting down a chute and repeats the whole process with a new casting.
“Getting the robot up and running was so time consuming because we have many different castings in production and each has to have different ‘gripper fingers’ and pads for the turntable. Changing from one component to another takes ten minutes and initially the robot was programmed to use around 40 components.”
At that point the company found itself in a position where the robot had become too busy for the company to re-programme so they bought a second one.
The company has continued to modify the system to make ongoing savings. Within the robotic cell every tool had its own oiler system, however to check or refill the oilers meant shutting down the robot. The solution was to install a new lubrication system that has a reservoir outside the cell, which is programmed to control the lubrication to each tool. It checks and refills easier, and the company is using much less oil, making it a far more economical system.
The objective of protecting staff has been met with improvements in terms of health and safety. Paterson said: “We select the castings which we know are the most dangerous to fettle by hand and programme the robot to handle these first. This means that we can remove these castings from the band saw altogether, which has entirely eliminated the risk. In addition, the robot has greatly reduced hand/arm vibration and repetitive strain injuries. The man operating the robot is mobile and doesn’t have to spend hours sitting in one position, plus noise levels and workloads have been reduced by 80 per cent.
“Productivity has doubled and we’ve been able to reduce the lead time from cast to sale from one week to just 24 hours. A good example is one particular casting we make which would have once taken one minute thirty seconds to fettle, and now takes just 42 seconds! We’ve also improved the finished quality of our products through a uniform finish with no rough edges.”
The company is so proud of its achievements that they are keen to share their knowledge with others. To see visit: www.youtube.com/user/HallandBotterill
Mini mill innovative machining facility
Most recently the company installed a new mini mill, innovative machining facility, which is designed to work in conjunction with the robot.
Alex Paterson was trained to program the machine and a fettler was employed to operate it. However, there was going to be standing time for the man, so he also operates the robot, and does a small amount of linishing at the same time. Dead time, where the man could have been standing around has been eliminated. The fettler now feeds the milling machine, feeds the robotic fettling cell and linishes castings – a classic example of man and machine working in perfect harmony. Also, the skill is in the machine, not the man. Paterson explains the advantages of that: “When the operator went on long term sick, we employed a 20-year-old, with no confidence, and trained him how to operate the robot and the XYZ machines. Within a week he was happy and earning more money than he had ever earned before.”
The investment means the company can now offer machining capabilities. The mini mill – or XYZ 2-OP to give it its official name – is clearly designed to improve production without the need to employ extra skilled labour.
Alex Paterson and his staff are particularly pleased to receive recognition for their innovations and company achievements from the Cast Metals Federation two years in a row. “We’d like to take this opportunity to congratulate the other award winners and nominees as it was a privilege to be considered alongside such a wide range of companies working in the UK foundry industry,” he said. “We believe that we’ve created the very first affordable ‘jobbing’ robotic cell in the world and it’s been another fantastic year for us.”
Contact: Alex Paterson, Hall & Botterill Ltd, Tel: +44 (0) 113 237 4711, web: www.gutter.co.uk