Sean Delaney is a manufacturing engineering student at the AMRC Training Centre. Over the next 36 months, Sean will balance a hybrid of practical on-the-job training, academic study, and full-time employment at University of Sheffield's Advanced Manufacturing Research Centre (AMRC). He is being sponsored by IMTS, one of the world's largest industrial trade shows. As part of this support he will be producing an Apprentice Blog, providing weekly updates to share what he's learned, the equipment and technology he's using, and more.
I returned back to work in company at the AMRC Advanced Structural Testing Centre. Whilst there I was being taught to thread turn to further expand upon what I have been doing at the training centre. It was different to other types of machining I have done in that the given size may not fit perfectly with the nut you are producing the thread for, so it involves bringing the thread down to size until it fits the nut securely. This results in the job taking a significantly larger amount of concentration because the tool had to be removed from the work and the chuck put into reverse just as the tool entered the recess at the back of the thread. The precision needed to avoid crashing the tool was challenging but that just added to the enjoyment of learning the important skill that is thread turning.
I have been demonstrating the skills necessary to pass the CNC milling cell. I had to demonstrate the ability to prepare work on an angle plate, run a program on it, set two separate data within the same machine, and clock a datum around a circular pocket or extrusion with a DTI (dial test indicator). Setting the angle plate was quite simple since it is an easily transferable skill from the manual milling machines. Setting the datum around a circular pocket was quite difficult because I had to spin the DTI around the pocket; this would result in the dial facing away from me so I had to use a mirror to see it, but this reversed the image so I had to interpret its readings backwards.
I have continued to work on my assessment piece on the CNC milling machine, having used similar tools to those used on the manual machine. The assessment piece is a steel block on which I have to demonstrate different processes, similar again to the manual machine. I had to program the machine, set it, and run it. That involved creating pockets, drilling, tapping and reaming. I had a near miss whilst running it. I watched as the drill approached the work in a way that was unintended and was about to hit it but, I luckily pressed the emergency stop in time. Others in the group have not been so lucky since many have crashed their machines. Success and failure are all part of our learning process.
This week I have been learning how to manually set the CNC milling machine and run a pre-designed program. This was surprisingly similar to the manual milling. I expected the machine to have an internal detection system that could set the machine to the workpiece. But instead, many of the functions were similar to manual milling, such as finding the zero with the wobble bar and setting the vice square with a DTI (Dial Test Indicator). Another interesting change was how the machine could hold all the required tools and how you had to set the tools in accordance with the program. It was quite tense when I set the machine running for the first time since, but luckily I completed the piece without breaking any tools.
On ‘return to work Friday’ the AMRC ASTC team were kind enough to allow me to continue my professional development as I saw fit. So I decided that I would continue to make improvements to my vice beyond what was required in the assessment. I decided to drill a hole through the knurled handle to accommodate a steel tommy bar. I then began to make various jib strips from different materials, such as brass and PTFE so that I could decide which material best suited for each application. I very much enjoyed doing this because it made the vice feel more like my own creation because I had gone further and made my own alterations and improvements rather than just following someone else’s drawing.
I have finished the paperwork for my vice and therefore completed manual milling. I am very happy with how the past seven weeks went as I now feel comfortable and able to undertake manual milling in the work place to a good standard. On Monday we moved onto CNC milling where I will spend the next seven weeks. The machines we will be using are manufactured by HAAS but until then we will be practising on simulators which have an identical control panel to the machines. We began on the machine by programming some simple codes like having the spindle move in the X and Y plane in the shape of a square with radii and chamfers on the corners. It was much easier than I had expected as all the information on the monitors at first seemed quite overwhelming but it took only a few hours before I could program some simple functions.
This past week I completed my vice. I had to produce two jaw plates, the jib strip and retaining plate as well returning to the main vice body to bring the ends down to size and produce the various threaded holes. To do this I had to fit an angle plate to the bed of the machine and clock it with a DTI (dial test indictor) to set it square to the machine. I then deburred and polished all the pieces. It was a great relief when all the pieces fitted together after some filling and re-running dies and taps through the more difficult pieces, but I was very happy when it all finally came together. I then helped some others who were still finishing, particularly with clocking the angle plate square. I am currently working on the paperwork to sign off on the project, which is a necessary part of learning to be an effective machinist. I am looking forward to moving onto the CNC machines next week as I have never used one before and it will be a totally new experience.
Last Friday was the monthly return to work day. The team at the ASTC had delayed working on a testing job from the AMRC Composites department so that I could participate and get to know the machines. The job involved tensile testing different bonding methods for bonding carbon fibre. I found this particularly interesting as it meant I was able to observe the instruments generating graphs relating to what I had studied in physics at school. It felt very vindicating that I could now apply what I had learned at school to the work place, which at the time of learning could sometimes feel abstract and somewhat irrelevant. Back at the AMRC Training Centre I have moved on to some of the smaller components for the vice project. I have produced both jaw plates and I am in the process of milling the jib strip. When I get to drilling the holes I will have to place it in an aluminium jig that I had made previously to hold it in place. I am looking forward to this process since I will be using an accessory of my own making in combination with the machine
This week I have continued to work on my vice. I have completed the vice body and have begun to produce the moving jaw. I have blocked the steel piece up, produced the step and threaded the holes for the brass packers and the vice screw. I have also performed my presentation on the AMRC Advanced Structural Testing Centre (ASTC). I spoke about some notable tests such as the one conducted on the Game Bird light aircraft as well as the physics involved in structural testing (for example, the young modulus graph and how it is calculated). I also spoke about the testing centre’s capabilities in regards to various machines and testing procedures.
This week I have finished my manual milling exam piece, which met every tolerance, and I completed all the relevant paperwork. After every project we have to complete a small booklet in which we reflect on the process of making the project; this includes talking about any problems we encountered, the tools we used, and the calculations we made. Additionally, this week I have begun my competence piece which is a toolmakers vice. I have already produced the screw whilst working on the manual lathe last month and up to now, I have blocked up the piece of steel and have begun to machine the slot in which the moving jaw will slide.Working at the speed I am, I will have finished all my exams and projects with three weeks spare to work on an extension project of my choosing on the milling machine.
This week I have further developed my skills on the manual milling machine to include the ability to machine aluminum. I used an engineer’s reference book to acquire the relevant information and equations in order to calculate RPM speeds and traverse feed rates for the required material. I am now beginning my assessment piece. It is a mild steel block on which a series of skills will be demonstrated such as blocking up: this is where you make a block of steel square in order for it to be machined effectively and to tolerance, producing pockets, slots, drilling, countersinking as well as achieving the required finish.
I spent this past Friday back at the testing centre, as one Friday of every month we go back into the company for the day to apply the skills we have developed at the training centre. Whilst there I was asked to produce, on the manual lathe, some 10mm rollers for a four-point bend rig. It will be used with an Instron testing machine that will apply the compressive force from the machine perpendicular to the test piece. Also while at the training centre, on the manual milling machine I have learned how to produce grooves, pockets, and how to work at angles. Once we have developed adequate skills on the manual mill, we will produce a vice which will serve as our examination piece.
After completing my seven weeks on manual turning and achieving a distinction, I have this week moved on to manual milling where I will spend the next seven weeks. So far, I have learned how to face off a steel block, similar to that which would be provided in industry in preparation for beginning the job, as well as how to prepare (set up) the machine for work. For example, clocking the ram and head, and running safety procedures such as testing the guards and emergency stop buttons. I have also been in the classroom this week, where we have three separate classes: health and safety, maths, and engineering communication. In the communication class, we are developing our presentation skills. For our first assignment, we have to prepare and then present on our places of work.
After spending several weeks at the AMRC Training Centre I was presented with an opportunity to volunteer to assist staff during an open evening during which I assisted my trainer in leading tours around the workshop and answering any questions that the visitors had. When we visited the manual lathe cell, within which we were currently working, we showed the visitors examples of work that future apprentices might expect to produce and gave a basic explanation as to how it would be produced. We then took the visitors to see the other places of work for different apprenticeship paths such as welding and tech-support.
The practical work in regards to the machining apprenticeship at the AMRC Training Centre focuses around five work cells: CNC turning, manual turning, CNC milling, manual milling and hand fitting with approximately seven weeks spent in each cell. Currently I have one week left on manual turning, so far having done some development work to practice and learn skills such as calculating RPM speeds and feed rates whilst using a wide range of tools to produce what was shown in the engineering drawing. We have worked with mild steel, aluminium, brass and nylon using both high speed steel and carbide tipped cutting tools. I then had to produce my assessment piece - which was a hammer - on which there would be examples of skills I had acquired, for example knurling, tapering and threading forming. We were given an engineering drawing form which we had to produce a plan and job card and then produce the work piece to within the tolerance independently.
I have spent these last two weeks with the team in the Advanced Structural Testing Centre (ASTC) getting to know my new colleagues before beginning my training over the road at the AMRC Training Centre. During my time at the training centre I will be studying machining, programing, fitting as well as the relevant maths and science for the next 36 weeks in the centre’s state of the art facility at the end of which I will return to the ASTC. I would like to thank Phil Spiers who is head of the ASTC, Adrian Allen who is a co-founder of the AMRC, Peter Eelman and Bonnie Gurney from the AMT, and the wider AMRC and AMT/IMTS for allowing me this wonderful opportunity.
Leave us with some details and we will provide you with more information.