C10 Application of quality control and quality assurance
Initial knowledge/skills rating *
September 2011
I know that in manufacturing, quality control is about setting boundaries within which a product must fit. For example the measurements of a sheet of material must be within a certain tolerance. Standards may be set by governing bodies such as trading standards for example scales in shops must be accurate to a set decimal point but other than this vague understanding I know nothing.I must carry out some research into quality control and quality assurance because I think I probably know a bit more than I realise.
I know that in manufacturing, quality control is about setting boundaries within which a product must fit. For example the measurements of a sheet of material must be within a certain tolerance. Standards may be set by governing bodies such as trading standards for example scales in shops must be accurate to a set decimal point but other than this vague understanding I know nothing.I must carry out some research into quality control and quality assurance because I think I probably know a bit more than I realise.
Ball bearing game
I have realised that what I class as wanting to make a good quality product is in fact applying quality control methods. Unhappy with my first attempt at ball bearing game I had another attempt this time I even included the ball bearings! However when I heated and shaped the clear upper section it did not go as well as it had the first time. The casing had a small gap that would have meant I could not have made a seal all the way around.
I reheated my plastic and had another go. The same thing happened again. Despite my mould working fine the first time I decided to add more blocks so that when I closed the vice the pressure would be spread more evenly. This time I had a successful outcome.
Smoothing the edges is exactly what is meant by quality control.
I reheated my plastic and had another go. The same thing happened again. Despite my mould working fine the first time I decided to add more blocks so that when I closed the vice the pressure would be spread more evenly. This time I had a successful outcome.
Smoothing the edges is exactly what is meant by quality control.
Parts to make up Spidy
Another example of ensuring quality was examining each piece of my spider. The holes were not always round but with a little filing the LEDs fitted through.
Although each hole accepted a prong without any difficulty when the two halves were placed together they did not fully go together this was probably due to accumulative error. Once again with a little filling the two halves went together neatly.
Pewter cast shells for hooks
A little filing of sharp points and the removal of excess metal ensured all pewter cast shells were of an equally high standard.
Because I was using an open mould it was possible to over and under-fill it. Although a little variation due to the handmade nature of my product was good, I set up my own quality control re-melting castings I thought too large. I had not planned on using the casting that was too small but had not melted it down when I decided it was just the right size to go on the sliding shelf.
Because I was using an open mould it was possible to over and under-fill it. Although a little variation due to the handmade nature of my product was good, I set up my own quality control re-melting castings I thought too large. I had not planned on using the casting that was too small but had not melted it down when I decided it was just the right size to go on the sliding shelf.
I had planned to use my pewter cast shells to screw into the
side of my bedside cabinet and hang jewellery from them. Of course the screw could
potentially cause damage my jewellery so I covered each one using a clear
flexible plastic tube. I was able to cut each piece of tube to the same length
which not only provided a quality finish to the product but also meant each hook
would protrude by the same amount.
12th February 2012 ***
A lot of what I do naturally is quality assurance and control. Looking for areas to improve such as removing sharp edges and burrs was something I was taught as an apprentice or even as a child by my father who had a very critical engineers eye and was not satisfied unless my work was perfect. By thinking about this unit I am able to become aware of how I employ quality control and quality assurance to produce my own work and therefore how I would teach that to others.
In engineering I was familiar with using tolerances. Anything that falls outside of that tolerance is rejected. This ensures products are made to a repeatable standard. Of course the tighter the tolerance the less room there is for variation.
To improve my knowledge further so that I feel confident sharing and teaching it I need to have a definite definition for quality control and quality assurance. At the moment I would give a rather woolly explanation. To do this I will visit BBC bite size or similar.
Design innovation project *****
July 2012
Because I was designing and making a project for someone else I was a lot more conscious of my own quality control methods. Because the activity board is to be used by vulnerable children I was even more conscious that my standards had to be high. Every choice I made was about strength , resilience, ascetics, function and safety versus weight, availability and cost.
I was particularlly conscious of the quality of the finish as I was using unfamiliar materials. The Modrock brick surface gave me a lot of difficulties that I had to overcome. I had not realised the Modrock would shrink when it was made wet. So my bricks shrank back from the masking tape screen. I touched the surface in using Gesso only to find whenI applied the emulsion finish the paint took differently to the Modrock leaving the Gesso area like a lighter outline around the bricks. Th sonly way I could think to deal with this was to disguise the lighter banding using painting techniques . i broke up the light area by stippling darker paint over the top. When I revved the masking tape I removed some areas of bare plater were showing through. They needed to be touched in with paint. Then there were little threads sticking out from the Modrock which I knew the average child would pick at so they had to come off.
Finishing the project to a high standard was very time consuming and tested my patience to the limit. My project is 700mm by 1700mm. That is a lot of brick work.I had never worked with artificial grass before and carried out many tests in the way I cut and secured it. I carried out many tests checking the strength of the design all the way through this project.
I have learnt if you want a good product you must allow a lot of time to finish it well. I think myself and a lot of people are under the misconception that applying a finish will be quick and easy. After all is is very quick to say and then I will 'varnish' it. Easy yes quick no. What we should really be saying is I will stand there sanding until my product is really smooth. Varnish it which will raise the grain. Lightly sand it again. Varnish it. Let it dry. Varnish it again. Let it dry. And when you start thinking about it like that to get a good finish you have to allow time for a lot more then a quick coat of varnish.
Because I was designing and making a project for someone else I was a lot more conscious of my own quality control methods. Because the activity board is to be used by vulnerable children I was even more conscious that my standards had to be high. Every choice I made was about strength , resilience, ascetics, function and safety versus weight, availability and cost.
I was particularlly conscious of the quality of the finish as I was using unfamiliar materials. The Modrock brick surface gave me a lot of difficulties that I had to overcome. I had not realised the Modrock would shrink when it was made wet. So my bricks shrank back from the masking tape screen. I touched the surface in using Gesso only to find whenI applied the emulsion finish the paint took differently to the Modrock leaving the Gesso area like a lighter outline around the bricks. Th sonly way I could think to deal with this was to disguise the lighter banding using painting techniques . i broke up the light area by stippling darker paint over the top. When I revved the masking tape I removed some areas of bare plater were showing through. They needed to be touched in with paint. Then there were little threads sticking out from the Modrock which I knew the average child would pick at so they had to come off.
Finishing the project to a high standard was very time consuming and tested my patience to the limit. My project is 700mm by 1700mm. That is a lot of brick work.I had never worked with artificial grass before and carried out many tests in the way I cut and secured it. I carried out many tests checking the strength of the design all the way through this project.
I have learnt if you want a good product you must allow a lot of time to finish it well. I think myself and a lot of people are under the misconception that applying a finish will be quick and easy. After all is is very quick to say and then I will 'varnish' it. Easy yes quick no. What we should really be saying is I will stand there sanding until my product is really smooth. Varnish it which will raise the grain. Lightly sand it again. Varnish it. Let it dry. Varnish it again. Let it dry. And when you start thinking about it like that to get a good finish you have to allow time for a lot more then a quick coat of varnish.