AGSB
Clinometer Project Design & Technology James Persico
2011
Situation For a house extension my parents are planning on building, they need to know the height of a certain tree in the west, as it may be tall enough to block the sun in winter evenings and make the house less energy efficient. Since it would take too much time and effort to measure the tree using a tape measure, a ladder and a very long rope, I need to make a product to help me work out the heights of objects far away, with reasonable accuracy.
Brief I will make a clinometer, which uses basic trigonometric functions to calculate the height of an object based on you knowing the distance from the object, and the angular measurement from the horizon to the top point of the object.
Trigonometry Information Trigonometry is the name given for a various list of functions which can calculate a certain property of a triangle given at least two other properties. Below is a diagram of an average right angled triangle, with the correct algebraic letters assigned to each line.
H O θ A The longest line is the hypotenuse, the one opposite the relevant angle the opposite, and the remaining one is called the adjacent. This popular mnemonic is used to memorise the simplest trigonometric functions SOH-CAH-TOA (rhymes with Krakatoa) This stands for Sine(theta) = Opposite/Hypotenus Cos(theta) = Adjacent/Hypotenuse Tan(theta) = Opposite/Adjacent (Theta is a Greek letter used in maths to denote the angle of the triangle that is between the adjacent and the hypotenuse) Sine, Cosine and Tan are trigonometric functions. Their outputs are given on the following graph.
4 3.5 3 2.5 Sine
2
Cosine 1.5
Tan
1 0.5 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
1
1.1 1.2 1.3
In the case of my clinometer, I could either In this scenario, the one I will need to use my clinometer in to fulfil the brief and specifications, I will need to calculate O. For this I must know theta, the hypotenuse and the adjacent. Theta will be the variable angle at which the clinometer is set during use. The adjacent will be a fixed distance, which the clinometer will label, at which the user must stand from the object in order to get a reliable result Tan (theta) = Opposite(to be calculated) over adjacent (10m) Let’s say the angle measured is 30o Tan 30 = 0.577 0.577=Opposite/10m (times 10 both sides) 5.77 = Opposite Therefore, the height of the object would be 5.77m
H O θ A (10m) (10)
Specifications
It must be hand held (✓ The product fits comfortably in the average hand) It must measure the height of an object (✓ The product does this) It must be ergonomic (✓ This could be improved, although it is quite easy to hold) It must not resemble a gun (✓ It looks nothing like a gun) It must have a locking mechanism (✓ ‘Squeeze to freeze’) It must have instructions and details of calculations needed (✓ See provided leaflet) It must use a standard 70mm clinometer calibrated disc (✓ It does) It must have a method of measuring the horizon (✓ Weight ensures this) It must have a method of measuring inclination of angles (✓ The product does this) It must be easy to use (✓ Once the instructions are read)
Final Design
Clinometer body Clinometer disc
Axle
Spring
(The design is false colour to differentiate between different components) My design is simply yet effective. To lock the disc, simply squeeze the sides together with your fingers, and the disc will jam. Otherwise, the springs hold the sides apart and ensure the disc can spin freely. I will aim to produce one component per lesson, and spend two finishing the plastics with abrasive paper.
Plan of Manufacture Line Bender When I had cut out sufficient acrylic for my project, I used a whiteboard pen to mark out where I had to bend it. This was to ensure the resulting curve was not wonky, and meant I didn’t need to hope for the best when bending the plastic. I drew the line using a rule and then placed the acrylic on the line bender with the line directly above the heat. I regularly checked the plastic to ensure it didn’t get too hot and weaken the structure. When the plastic was suitably bendy I bent it around a piece of plywood that ensured the clinometer’s body didn’t a.) Set unevenly b.) Snap later on when I abraded the edges of the plastic
Filing the corners To avoid dangerous, jagged edges, I used a file to curve the sides of the clinometer. First, I placed the plywood back in the middle of the two acrylic sides to give more structural strength to the clinometer while it was being worked on. Next, I took the file and abraded the angle at a perpendicular to the longest side of the body. This meant the acrylic stood less chance of snapping or being weakened. After this I ridded the acrylic of the plastic fibres that had gathered.
Abrading the corners To abrade the corners I used abrasive paper, starting at P60, and up to P1000, to create smaller and smaller scratches in the acrylic until they were almost invisible. If I had only used the P60, the clinometer body would still feel rather rough to touch, but after using all the paper available, in the correct order, I was able to obtain a desirable finish to the plastic. After I had used all the P number paper, I proceeded to use the Wet and Dry. When dampened, the wet and dry paper becomes even more abrasive. CAUTION – When abrading using abrasive paper, wrap it around a file, due to the friction involved with such harsh abrasion, a lot of heat is given out, and could burn your fingers.
Making a Sticka To use the Sticka machine, I first made a design in Techsoft 2D and made sure the letters were only outlines. Wherever there is a mark on the drawing, the machine will cut. This means if the text was filled in, in any colour, the machine would rip apart the Sticka paper, possibly damaging something. My Sticka, however, printed very well, and the picture in the evaluation shows this.
Drilling the holes I drilled two holes in the product, one for the axle, and another for the clinometer reading to be shown through. The smallest was done with a twist drill bit with a diameter of 8mm, and the largest with a forstner bit with a diameter of 15mm. The smallest was for the axle, and the largest for the reading. Here is a picture of the drilled holes being put to use.
Height of object appears here (m)
Axel which the disc spins around
Evaluation My product met my brief, and helped me solve the problem of the tree’s height. The tree was 10m tall, and this was calculated using my clinometer: The tree will not block out the sun in winter! My design could be improved by smoothing the disc, which is still rather rough, and the inner sections of the drilled holes. Overall, I am pleased with my product, which has shown itself to work effectively in a real life environment, and is aesthetically pleasing.
Delta Tech Clinometer – Instructions for use
Stand 10m from the object you intend to measure. Place the clinometer in your left hand, with the delta facing right. Tilt the clinometer until the metal nut aligns with the object you’re measuring Clench the clinometer shut. Look at the reading on the clinometer. If you stood 5m from the object, half this. If you stood 20m away, double this. Congratulations, you’ve just used a clinometer!
三角洲科技倾斜仪-使用说明 •独立的对象，你打算衡量10米。 •把你的左手测斜仪和珠江三角洲面临的权利。 •倾斜，直到你的对象对齐测斜仪测量金属螺母 •咬紧了测斜仪关闭。 •看的测斜仪读。如果你站在从对象，这500万的一半。如果你站在20米以外，翻番。 •恭喜你，你刚刚使用了测斜仪！
Delta Tech chyłomierz - Instrukcja obsługi • Stand 10m od obiektu, który zamierza środka. • Umieść chyłomierz w lewej ręce, z delta prawo jazdy. • Tilt chyłomierz do wyrównuje metalową nakrętką z obiektem jesteś pomiaru • Clench chyłomierz zamknięte. • Spójrz na odczyt na chyłomierz. Jeśli stała 5m od obiektu, połowa. Jeśli stał 20 metrów, dwu-to. • Gratulacje, używane tylko chyłomierz!
ةال ت ق ني لال مي م ق ياس ادل ت-- مل ال س تخذا تت ع ل يما • فال وق و10m سق يا يت نو يال ذ ال كائ ن نم. • ىال ي سر كي د يف لال مي م ق ياس عض، ت واجهها ادل ت قال ح عم. • سق يا تك ن نال كائ عم نال م عاد زال جو ةمحاذا ىحت لال مي م ق ياس ةإمال • مغ ل قة لال مي م ق ياس ىعل ماإلح كا. • لال مي م ق ياس ىعل ةال قراء ىإل اان ظرو. توق ف تك ن اإذ5m نال كائ نم، اهذ فون ص. اب ع يد توق ف تك ن اإذ20m، اهذ م ضاع فة. • كم برو، !لال مي م ق ياسو ل ك طف ق تا س ت عمل ل قد
Delta Tech clinometro - Istruzioni per l'uso • Posizionarsi 10 metri dall'oggetto che si intende misurare. • Posizionare il clinometro con la mano sinistra, con il diritto delta di fronte. • Inclinare il clinometro dado fino a quando il metallo si allinea con l'oggetto si stamisurando • Stringete il clinometro chiusa. • Osservare la lettura sul clinometro. Se si stava 5 metri dall'oggetto, la metà di questo.Se si stava 20 metri, il doppio. • Congratulazioni, avete appena usato un clinometro!