Intro: LED Light
The students can choose either to make a desk light which is more functional, or a mood light which is more aesthetic. Check out the video to see how the magnetic switch adds extra awesomeness to the product.
Students will design and make either a functional or decorative light. The design process reflects how professional design engineers work by teaching students creative designing skills to produce a unique and original design idea, and then how to make a virtual prototype using 3D CAD software. To stretch and challenge the students the project introduces more advanced measuring and marking skills, metal fabrication and forming, the properties of thermo / thermosetting plastics and how to manipulate their properties to make the design. The students will be introduced into basic electronic components and will be required to neatly house the circuit in their lamp. Lastly the students are required to recall and apply prior learning and knowledge of using engineering machinery and joining methods.
This project costs approximately £2.50 per student
I have attached the project work sheets
Step 1: Creative Designing
- Sliced Peppers
- Sliced Oranges
- Any tropical fruit....sliced
- Architectural plants (see photos)
- Any other natural item that has a structure or pattern e.g. wood grain
If you look at the 'Ideas' page you can see that the design does not look like the inspiration image, this does not matter, the images are there to inspire shapes......there is no right or wrong here......if you end up with a design......mission accomplished :)
Step 2: Card Model
Give the students pre cut card to the size of the materials provided
Blue card = 155 x 110mm
Black card = 155 x 110mm
White card = 130 x 125mm
Using glue guns, tape etc...shape the card by hand to assemble a model of their design idea.
If any issues have been discovered from making the model make the required changes and create the 3D final design. This allows the students to practice their isometric sketching and also allows them to apply their engineering knowledge to annotate the page. I encourage the students to use exploded and cross-sectional drawings to help communicate their ideas.
Step 3: 3D Final Design
- 3D sketches
- Exploded views
- 2D drawings
Step 4: 3D CAD
We use SolidWorks but if you don't have any 3D software there are free CAD packages like Autodesk's 123D or google sketchup..... Both of these can produce excellent results and its free for schools to use.
You can produce 2D working drawings from the 3D virtual model......these are useful when making.
This is an ideal opportunity to teach the students about the exam theory on the use of CAD/CAM in industry. there are plenty of short vids on you tube you can show which clearly show automated machinery and mass production
Step 5: Lamp - Aluminium Sheet
- Using precut aluminium 110 x 155 x 1.2mm
- Using the dimensions developed from the 3D virtual modelling stage measure and mark out the aluminium sheet.
- Centre punch the hole positions
- Drill the holes at Ø4mm
- De burr the holes
- Use 150grit abrasive paper to give the aluminium a 'brushed' look
Step 6: Lamp - Aluminium Sheet
- Shape the aluminium using rollers for curves and folding bars for right angles
- Use 150grit abrasive paper to remove any marks from rolling
Step 7: Acrylic
- Using precut acrylic 110 x 155 x 3mm the students need to mark out their design, the sheet can be cut into a shape or used complete.
- Leave the protective film on the acrylic as this prevents scratches
- Mark out the hole centres on the acrylic sheet using a biro.
Step 8: Drilling the Acrylic
- Using a Ø5mm drill bit and a pillar drill create the two holes as per your marking out
- Ensure goggles are worn, hair tied back and sleeves rolled up.
- Drill slow and hold the acrylic down with a lot of pressure to avoid it shattering
Step 9: Sanding Acrylic
- Use a sanding board with 150grit paper on it to remove saw marks from all four edges
- I also used wet&dry paper to polish the edge
Step 10: Thermo-forming the Acrylic
- Set an oven to 170oC / If you do not have an oven you can use a heat gun / paint stripper
- We use aluminium formers, other options are MDF or Pine
- I have a number of aluminium strips 110 x 155mm for the students to create a former for their design by rolling and folding. I keep all the formers so they can be reused/modified for next years group.
- REMOVE THE PROTECTIVE FILM!!!!
- Put the acrylic and aluminium former in the oven and leave for 5mins.
- Wearing heat proof gloves check to see if its ready by pushing the acrylic.....if its flexible, its ready
- You sometimes have to use light pressure to hold the acrylic in place as it cools (See photo with two bits of wood)
Step 11: Lamp - Aluminium Tube
- Provide the Ø38mm ally tubes pre cut 20mm bigger than the ally sheet
- Face both ends
- Use a half round file to remove the burrs inside the tube
Step 12: Lamp - Aluminium Tube
- Use a digital calliper to accurately measure the diameter of the tube (i know its standard Ø38mm tube but the kids do not)
- Place the tube in a V-Block and place on a flat surface like a marking out plate
- Using a height gauge to measure the overall height of the tube + block (this measurement = X)
- Take the tube diameter measured in the last step and divide by two to get the radius (this = r)
- Do the sum X-r = Centre of tube (my sum was 48-12.5 = 35.5mm) set the height gauge to this height and scribe the centre line of the tube
Step 13: Aluminium Tube - Marking the Hole Centres
Measuring from the bottom of the tube, then drill, using a V-Block, centre punch and drill
Bolt Holes Ø4.2mm
The bottom hole will be 20mm
The top hole will be 90mm
LED Holes Ø5mm
The bottom hole will be 30mm
The top hole will be 80mm
Using an M5 tap thread the four bolt holes
Step 15: Brushing the Ally Tube
Using a lathe set to low speed, and 150 grit abrasive paper......sand the tube. The second picture shows the difference between sanded and not sanded.
Swap the ends round and sand the bit that was in the chuck.
Step 16: Aluminium Dial - Turning
Parallel turn the top of the lamp on a metal lathe. Turn the cutting tool at a 45degree angle to cut the O-ring channel
Step 17: Aluminium Dial - Knurling
- Knurl the grip....use low speed...(approx 100RPM)
- Part off the work
Step 18: Aluminium Spacers
- Use Ø8mm aluminium rod
- Centre drill
- Drill Ø5mm approx 30mm deep
- Part off at 13mm
- Repeat 3 more times
Step 19: Magnets
Use epoxy resin to stick on the Ø5x1mm neodymium magnets.
Step 20: Circuit
- Using 4 super bright LED's, 360 ohm resistor, PP3 9v battery and the magnetic contact create the circuit as per the diagram.
Step 21: Insulate Wires
Use insulation tape to protect any exposed wire, you must do a good job of this as the LED legs are particularly vulnerable to shorting on the ally tube if not covered properly.
Step 22: Install Circuit
- Carefully add the circuit to the ally tube.....careful is the word if you force the circuit you are likely to snap wires
- I use a plumbing pipe clip to hold the reed switch in place
Step 23: Asssembly
- Use M5x20mm bolts to assemble the aluminium and acrylic sides
Step 24: Students Work
The students work is graded on the following criteria
- Quality of surface finish
- Quality of fabrication and shaping of aluminium & acrylic
- Creative thinking
- Complexity of design
- Technical detail on design page