This table was made for my product design coursework and I would love to hear your reviews on it. I have copied and pasted directly from my coursework so sorry if there are bits that do not make sense. Would you please be able to give me as much feedback as possible so I could use it in my coursework.
My work starts here:
I am going to design and manufacture a coffee table complying to the art deco movement. All living rooms need a coffee table at the heart to bring the room together. The colours will have to be neutral as it these colours can fit in with any styles. To make my coffee table will be unique and better than similar products, I will make it;
Easy and cheap to manufacture Designed to a set theme (art deco) Foldable or adjustable My target market consists of young adults who have recently bought a home and anyone who wants to class up their homes. The materials I could use are pine because it is sustainable and recyclable and metal standard components. The size will be in the range of 900mm x 500mm x 500mm. It will be made in school because there are lots of tools and machines to use.
Step 1: Gathering and Measuring
In this lesson, I measured and labelled all my materials and made sure everything the technician gave me was the right size. I did this to make sure all my pieces met the cutting list and my design requirements. To make sure everything was perfect I used vernier callipers to measure the thickness of each piece of wood. Part 2 on my cutting list was 15mm and when I measured it, it was exactly right. Parts 4,5, 6, 8 and 10 were all 9mm on my cutting list and the were also right. I then use a measuring tape to get the lengths of each piece, all of the pieces were 10mm off the size I asked for but this was good because I did not consider the errors that could occur if I cut on the line and I did not consider the size of the router bit. Afterwards, I marked out the midpoint of parts 2, 4, 5 by drawing a line from the corners to the opposite corner so I could nail the router jig to make the rings on the pieces. The pieces I marked out where all squares so the lines from the corners had intersections at 90 degrees, this is important to get the places for the each hole perfect.
Alternatives: If the laser cutter was big enough or if we had a larger CNC cutting machine I would design all this on 2D techsoft and get it measured and cut automatically, accurately and with as less waste as possible but sadly we don’t, however, this would be the quickest way to mass or batch produce it. Because this is a one of production and I am doing this at school, I would have to mark out everything I cannot laser cut by hand and cut it out with tools and non-computer controlled machinery
Problem Encountered: I did not encounter many problems because all I had to do today was mark out what I had to cut my ring pieces and make sure I had everything to the right size in my cutting list. However, one problem I did have was that part 6 (level 1) was cut as one 450mm by 450mm piece.
Solution: To solve this issue, I had to draw a line on the midpoint of one of the sides. I did this by measuring that edge and calculating half the length. Then I marked it out with a pencil and then I did the same on the opposite side. The piece again was a square so the line connecting the midpoints were perpendicular bisectors. Then I asked the technician to cut that out for me with his circular desk saw. He cut it out for me and I then measured out the sizes of the 2 pieces created, they were right.
Step 2: Cutting the Rings
To see what I had to do this lesson, I looked at my production plan and read that I needed to cut the rings. I took out my work and asked the technician for the handheld router. He gave me a plank of scrap ply board for me to use as a jig. I measured the radii of the sizes and marked that out and drilled a 15mm hole for the router bit and a 1mm hole for the nail (which would be hammered into the centre of the circle). I had to do was to mark out the radius of each ring (taking the drill bit size into account (so it is exactly right)) and drill a 2mm hole at each part. Then I hammered the nail a tiny bit into the centre of level 4 to so it would be easy to line the jig up with the centre. Afterwards, I used a hammer to hit the nail through the 450mm hole and the level 4 piece. The technician had to supervise me the whole time so the router bit would not fall out. I turned on the router and pushing down half way into the work to make sure it would work. The technician then turned on the vacuum cleaner to gather the dust, he gave me a dust mask and a pair of goggles so I would not breathe any of the dust in. I slowly turned the router around the pivot point (The centre) and it created a perfect circle. I then pushed the router down to the full way down and cut it out. I then measured the diameter of the circle created and it turned out perfectly. I then took out the nail with the claw end of the hammer and then I hammered the nail through the nail and the 362.5mm (this length should have been 375 but I had to take away 12.5 to account the size of the drill bit) and cut out the circle with the router. I did this process of cutting the rings and measuring out the next hole while taking into account the router bit size with the rest of my pieces (parts 4 and 5) Alternatives: In industry, a quicker way to do this would be to use a CNC router or laser cutter. The laser cutter would be a better choice as it would create less waste and there would be less dust created from the drill Quality control: To make sure that the rings I cut were perfect circles, I used a jig where one side was nailed to the centre of my work as a pivot point (like in a compass) and the other side was clamped to the router. The jig I used could cut perfect circles because it turned in a circular motion. The plank of wood was longer than it had to be (it could cut circles with a radius of 500mm). All I had to do was measure the distance between the front of the drill bit to each length, then the back of the drill bit for the inside circles. To make sure I got the right place for drilling the holes, later on, I went over the lines drawn in the previous lesson with more pencil (because they were starting to fade) to make it easier to line up in the next lesson. I sanded down the cut pieces with sandpaper to make sure the edges were smooth (so it is more ergonomic) and easier to spray paint later on.
Sorry, I do not have a good picture
Step 3: Drilling and Resting the Holes
I looked at the steps 3 and 4 of my production plan to see what I had to do this lesson. I read that I needed to create the jig for drilling the holes then drilling the holes. I started off by designing the jig brackets on 2D techsoft design and got that laser cut out of scrap acrylic. For the actual jig part, I created a template on solid works of what I had to cut out and then I cut out the angle with the band saw. I then secured my piece on the pillar drill table with a machine vice and drilled the 16mm hole into the jig. Afterwards, I set the jig and bracket up on scrap wood and tried to practice drilling the hole. Unfortunately, the jig did not stay in place when drilling the hole which meant I had to create a new bracket. This time, I used thick scrap wood and marked out the base of my jig on one of the sides. I then used the bandsaw to cut that out, then I filed down the back edge with a file to make it go at an angle so only one of the edges was the right length and the other held it in. The technician gave me a tiny scrap bit of steel and I bent it with the angle bender tool to the right angle and drilled 2 holes and screwed it into the jig. I used 2 G-clamps to secure scrap wood and my new jig to the table and practised drilling down. It worked perfectly so I drilled all the holes at each for points. I made sure each hole was in the right place my lining up the lines I drew earlier with the midpoint line of the jig. I the drill I was using at first did not have enough power (it was 15V), the technician gave me his 18V hand drill because the heat generated and the power need to drill the holes was too much for the 15V to handle. In the end, this whole process took 3 hours which is an hour longer than I had first anticipated.
To make sure all the angles were drilled in at the right angle, I used a jig which was measured and cut at the right size and angle. I made sure the angle was correct by using a protractor to see if it was at exactly 64° which it was. The positions of each hole was important because they needed to be at exact 90° to each other from the middle so they would line up. I made sure the positioning was correct by drawing perpendicular lines on lesson one and not rubbing them out, my jig also had a centre line which helped me line it up with the other lines. I checked all the all the lines met up when putting the dowel in by actually putting the dowel in. The dowels would not fit in the holes so I used sandpaper to sand it down to fit the hole. I sanded down and put all the dowels through all the holes and everything line up perfectly.
Step 4: 2D Techsoft
I looked at my production plan and did my first step. I had to skip this step until now because I needed the sizes for the lazy susan which took a while to come. I turned on the computer and logged on, then I opened up my SolidWorks design (to get the sizes for parts 6, 8 and 10) and 2D techsoft. For the base, I started off by drawing a 450mm diameter circle with the circle tool. Then I drew a line bisecting the middle of the circle and used the sectional delete tool to delete the bottom half of the circle. I had to cut 2 halves because the laser cutter is only 300mm by 600mm so the 450mm diameter circle would not fit. Then I set the angle marker tool to 45° which draw lines every 45°, so I drew three lines from the middle, one perpendicular to the bottom line and the other two 45° to the bottom line. I then drew a ⌀8mm circle 20mm away from the edge of the circle and used the transforming tool and rotated that circle from the middle 19 times and deleted the circles outside the line. I 37.5mm contoured the 45° lines and did tangent lines from the 45° line to these contoured lines. Then I deleted all the extra lines and the small straight part I made was for the legs. I did the few steps for my other parts as well but I did not do the stopper circles for them. For level one I drew an eighth of a design in a 160mm circle and mirrored that around to make a cool pattern. I deleted all the parts that crossed because so no parts would fall off during cutting. My final one was the same size but a 300mm diameter circle was cut out from the middle for the bearing spacer. Then I did a ⌀16mm circle 20mm from the top for the bearing and the spring. I saved all my parts onto a USB and took it to the laptop for the laser cutter and got it cut out. Sadly, this whole process took an hour to do, more than I expected.
I measured everything I drew with the measure tool and set everything to the perfect sizes by double clicking on the respected tool. I changed the layout to 600mm by 300mm in 2D techsoft to fit the laser cutter bed. The black lines were used to cut and went at 100% power and 10% speed to cut through the 9mm MDF. The green lines did vector engraving and were set to 5% power and 80% speed. Laser cutting is extremely accurate so I knew that I do not need to take into account any other size such as the size of the laser or anything because that was incredibly focused unlike a drill bit, this meant less waste and I could make the incredibly intricate design. When laser cutting, I turned on the extractor fan so no dust would get stuck in and damage the laser cutter. There was always a supervisor making sure the laser cutter did not malfunction and ruin my work and stop others from using the laser cutter. If there was an error while laser cutting, the operator/technician would have turned off the machine so the damage would be minimal, however, I am lucky enough to have my work completed quickly and without any error.
Step 5: Biscuit and Dowel Joint
I looked at steps 5, 6 and 7 on my production plan to see what I had to do this lesson. For the leg pieces, I first marked out wherever I had to cut with a steel rule and try-square. I cut a lap joint bit with a tenon saw and I used a chisel to make sure it was perfectly straight. I then I cut a jig with the at an angle of 30° with the band saw and I used it to cut the ramps on the legs with the band saw. I chose the band saw because it is very fast and with the jig, I could make identical ramps very quickly I switched on the bandsaw and pushed the each leg piece with the jig through to get the ramp. For the next part, I had to go off my production plan and put biscuit joints in my base. For this, I marked out 2 points where the biscuits could go. I put the biscuit jointer on where the mark would be and turned it on. I pushed down the thing and the hole was made immediately. I only did a biscuit joint on the base because the bearing spacer part and level one could have been glued in perpendicular to each other (like brickwork). I then used PVA glue the two parts of the base together (with the biscuits inside) and to glue the bearing spacer parts with the level one parts. To keep the base together I used a sash clamps to make sure everything was stuck together tightly. To make sure parts 10 and 8 glued together tightly, I used large spring clamps. For the dowel joint, I marked out where the holes should be (7.5mm either side from the middle) on the straight parts of the base, I did this on all 4 bits and put hole markers in and hammered the dots into the legs with a mallet. I did this with all the legs (numbering them as I went around) and drilled the holes down with a hand drill.
To make sure all the legs were cut at the same angle I created a jig out of scrap wood. This ensured all the legs were sloped at the same angle and all of them were identical to each other. This is good for aesthetic purposes as everything is ordered and the same, this is also good for speed as I could do all this very quickly. I marked out everything with a tri-square and a steel rule to make sure everything was accurate. To mark out the middle line for the dowel joint, I used a marking gauge and a ruler to keep everything consistent. The thickness of the base was 9mm so I had to mark out 4.5mm which was easy to do consistently using a ruler and a marking gauge to set it. To make sure the glue dried and attached the parts perfectly, I used a sash clamp on the base and spring clamps on level 1 and the bearing spacer part. This created a strong hold because the PVA glue absorbed into both of the materials and making them to merge. To make sure the holes lined up for the dowel joints, I used small hole markers , the holes were drilled to a certain length with hole stop, these two things had to be controlled so the legs would attach perfectly and without any errors, I also put numbers to make sure I remembered where each joint goes. I also marked out where the biscuit joints would be with a pencil and a tri-square, this made it easier to line up the biscuit maker with both of the parts.
Step 6: Cutting the Top and the Legs
Again, I looked at my production plan which told me to do step 8 (cut the top and the supports). I started off constructing the table, I required a little bit of help to keep all the levels in place while I slid the legs into place. This took a little while because the holes were quite tight. Once I put the table together, I made sure the top was level by putting a spirit level on it. I knew the table was level because the bubble was in between the lines. Afterwards, I used a marker pen to draw where I needed to cut, and I took out all the pillars, then I used a tenon saw to cut the supports. I did this by putting it in a table vice and cut it, to make sure the top edge was smooth, I used sandpaper to clean it. My next duty was to cut the top out of 2 pieces of 5mm acrylic, I did this by putting level 4 and using a marker to mark the curve. The marker had to be permanent so the markings would not rub off when I machine the acrylic. After I finished marking out the circle, I held the acrylic down on the cable with my hand and used a jigsaw to cut around each of the semicircles. I made sure to cut around a centimetre away from where I had marked out so if I made mistakes, they wouldn't affect my actual work. To get the curve to my actual line, I used a belt sander to curve it and to make it perfect. The belt sander was very useful as it meant I could create a perfect curve instead of trying to do it well with the jig saw. The jigsaw was useful as I could take away a lot of the big parts quickly even though it was difficult to do a good curve. I did not shape my plastic two quickly because if I rushed it, I would have messed up and because this was the 5mm acrylic, if I messed up, it would have cost me a lot of money because acrylic is the most expensive material on my list and it is not the most environmentally friendly material. Not because it can’t be recycled (it can because it is a thermoplastic) but because most polymers are made out of crude oil which is not too environmentally friendly.
To make sure all my top was perfect, I used level 4 to help me mark out the top because if there were any imperfections on cutting the top, it could be either too big or too small for level 4 which would not look as cool and would make it more difficult to mark out where to put the screw holes. I numbered each one of my support so I remembered which hole they would go in just in case one of the supports did not fit in another place or just incase the top would not be level. Numbering is quite helpful for remembering where they go because it will help me identify where they go. I then made the ends of the supports smooth by rubbing sandpaper over it and using my finger to judge the smoothness. Then I made the wet and dry paper wet and rubbed it on the edge of the curves of the top. Again, I used my finger to judge the smoothness because the belt sander left the acrylic quiet rough.
Step 7: Spray Painting
Finally, I looked at the final step in my production plan to see what I had to do next, I had to spray paint all the parts, all the levels and the legs had to be painted black and all the base and supports had to be painted gold. I started off by putting covers on the ground outside. I had to work outside because the ventilation box was too small for my pieces, to make sure I did not get any spray paint on the ground, I covered it up with newspaper and plastic. I laid my pieces on the covering and to prepare my work for spray painting and so the paint would stay on, I coated all my pieces with 2 layers of MDF sealer, I gave the parts 2 hours to dry between coatings. I sprayed the black parts first as there was a larger surface area to cover on them. I kept the can approximately 150mm to 200mm away from my work so the paint would cover more area quickly and efficiently. After I finished spraying the first layer of paint on all the parts that needed it, I let everything dry for another 2 hours before I did the second coat. I did 3 coats on the first side and flipped it over and did 3 on this side. I did all the previous steps with all the parts that needed to be sprayed gold. This process took a lot longer than I had first anticipated and therefore I had to do it over a few lessons and after school.
To make sure the wood would not absorb any moisture and so the paint will stay on properly, I used MDF sealer to keep the quality of my work. I did quite a few coats of spray paint so none of it would rub off or peel off. To make sure the paint was even, I spraying on the ground from one side and went all the way to the other side and back like a zig zag pattern, back and forth, back and forth. This kept everything even because when you press the button, a lot of paint comes out at the beginning and starts to fade off. I had to do small quick strokes at 20 cm away from my work to get the maximum coverage of the paint. I tested if I had done enough coats by dropping one drop of water on my wood, if it got absorbed or if the paint rubbed off, I needed to do one more layer. I also did a tiny scratch with my fingers, if any paint came off or wood would show, I had to do another layer. These tests helped ensure that I had covered everything and to make sure all of it looked aesthetically pleasing.
Step 8: Finishing Off
To finish off, I did not need my production plan because I had finished all the making steps of the table so I just had to finish off and put it together. I started off by polishing the edge of the edge of the top just to make the table look more aesthetically and a lot more user-friendly. This would help meet specification point “It must appeal to the target audience” because making the product smoother will make it more user-friendly which is more appealing to the target market. I made the edge of the top smoother by wetting a bit of wet and dry paper and wrapping it around the flat file. Using a flat file meant I could keep the edge straight. I went back and forth with the 240 grit wet and dry paper to make it smooth. The wetness created a little lubrication and the high grit meant the glass paper was finer so only small imperfections on the surface would be removed leaving a clean and smooth surface. I marked three holes on the of the halves of the top. Each of the holes was 37.5mm away from the circumference (because this was an exactly half of the width of the level 4 ring). Two were in the corners (15mm away from the middle), the other hole was on the perpendicular line from the midpoint of the edge of the straight edge of the semicircle. I put the top pieces on level 4 and used the holes on there to drill the holes through level 4 to make sure the screws lined up, I then used a countersink bit to countersink the holes so I could use countersunk screws and make the top flush. Instead of nuts, I made my own knurled nuts to make my product more unique. I did this by turning a piece of 15mm aluminium bar in the lathe and centre holed a 3.25mm hole in the bar. I did this by putting the 3.25mm drill bit in the chuck and tightened it with the chuck key. I pushed the on the lever and turned the forward/back wheel to clean the front and knurled the edge with the knurling bit, then I used the cutting bit to cut 8 10mm nuts. I collected the nuts and tapped M4 threads into the holes to make sure it is the M4 screws will fit in. I tapped by using turning the M4 tap in the hole (using the tap wrench to turn the tap) 360° clockwise and 180° back anticlockwise to make sure the thread was clear.I put together the top pieces with the Level 4 and put the rest of the pieces together using only a screwdriver (helped me meet spec point “It must be easy to assemble”). More detail on constructing the table will be in the assembling guide.
I used marked out the holes on the top with a ruler and drilled 4mm holes so the M4 screws would slide straight through and I used the top as a guide for the holes in Level 4 so the holes would line up. I put countersunk screws in the countersunk holes to make sure the top was flush and so I did not need to countersink anymore. To make sure the edges were smooth by touching it and judging it myself. Wetting the wet and dry paper was good for polishing as it provided lubricant when removing the tiny imperfections on the surface leaving a smooth and shiny finish.