David

I am a current ARA Apprentice, half way through my four years training.  The first six months of training were spent at Bedford Training Group (BTG) located in Kempston.  BTG was a fun and enjoyable environment, where there were other apprentices in a similar situation.  This helped the learning programme and helped me make good friends with fellow apprentices, in fact I am still in contact with them over a year later.  I spent my time on two sections, mainly machining and fitting, the two dominant sections at ARA.  When I finished my first year I was delighted to win ‘Craft Apprentice of the Year’, which in turn boosted my confidence.

Before embarking on the BTG, I spent one week at ARA and about an hour every Friday afternoon getting to know the people and the environment.  This was a big help when starting fully at ARA, not only did people know who I was but I also recognised them, this helped the settling in process.  During my first year I spent four months on the lathe, milling and jig boring sections.  Moving into my second year I have worked on fitting for four months and recently started on CNC, which will possibly be where I remain.  All sections have been enjoyable and it has been worthwhile learning what is best for me and the company while working with a whole host of different individuals.  I have always been looked after.   I personally feel I work in a great environment.  On Fridays I spend about two hours writing about what I have done in that week for my log book which is verified by my training officer from BTG.  This logbook is used as a record of my progress to show I warrant my qualification.

Once a week I go to Bedford College to study mechanical engineering.  I have just completed my ONC and look forward to moving on to HNC next year.  All the subjects are theory based and it makes a welcome break from the rest of the practical week.  All the instructors treat you like adults and care about you getting good results.  ARA staff are always willing to help with the subjects.  A lot of what I cover is used in the Design Office and not the Workshop and even though I am not a member of their team they have always found the time to help me.

Project Report

The small research model is designed for investigation of new aerodynamic test techniques in the small scale transonic wind tunnel.  The model is designed to demonstrate complex flows at low incidence, giving the opportunity to develop new techniques without recourse to the main transonic tunnel.

The test techniques which we plan to investigate using this model are:

Investigating the measurement of both steady and unsteady pressure using conventional ESP modules, including the attenuation of the unsteady signal along the pressure tube.

Development of Pressure Sensitive Paint techniques to investigate optimum methods of painting the model for maximum response with minimum intrusion.

To begin the project I cut a piece of S97 steel on the mega saw to the dimensions 180 x 155 x 35mm.  Then I milled the thickness to 25.2mm, leaving 0.2mm on for grinding.  I then ground the overall thickness to 25mm ready for CNC machining.

Before CNC machining I created five programmes using a CAD software package called ‘Rhinoceros’ and a CAM package called ‘Powermill’.  I then proceeded to run these programmes in the correct order, milling the work piece to +1mm to begin with on both sides.  After that I milled the job to +0.2mm, then I ran the finishing cuts and inspected the results with a DTI in the drill chuck whilst running the inspection programme.

After finishing the CNC machining, I held the job upright in a vice and drilled a 9mm hole through the work piece then bored the hole to the correct dimension +0.01mm.

I spent the start of the week on the lathes, copy turning the nose for my project out of S97 steel.  This is done using a template that was wired out and the machine follows the pattern of the template.  Then I had to turn a nearly 400mm long sting to a diameter of 20mm, the sting also had a nearly 300mm long hole drilled down the middle to a diameter of 13.5mm.  This hole took some effort and patience, after drilling the first 30mm needed boring to fit the outside diameter of the wing body spigot.  When all turning was complete and the surface was finished with emery paper and wet and dry, I moved over to the jig-borer machine.  I had eight holes to drill on the sting over a long area on a dividing head , this took some setting up and was very time consuming for myself.  The dividing head allows you to rotate the job around centre to certain angles.  When the set up was complete I simply drilled, reaimed, taped and counter sunk, where appropriate.