Box of Tricks and Fixing the Wheel Axles inside the Box - Assignment Example

Box of Tricks Insert Name Insert Name of University Insert Name of Course Insert Name of Professor August 16, 2012 Outline I Introduction II Construction A). Fixing the wheel in the box III Results IV Conclusion Reference List Introduction The parts of the wheel in the box of tricks has been design following instructions given in the case study, it has been tested by calculating velocity of spinning and angular acceleration. The technical aspects of design have been simplified to make easier for non-technical readers to understand the usage of the box of tricks. The designed box of tricks is not suitable for commercial but will be availed to the public with a few modifications are made. The task of making this rotating motor inside a box was not an easy task. In the making of this box I used jaw chuck, Screw-cutting, box door, tailstock with a centre that rotates and angular adjustable cross-slide. To help in centring the wheel in the box we need jigs, which is a disc with diameter of 100mm on the inside like the wheel. There is also power that will be used by a welding machine and Grinder. A flange for clamping will be needed to help in clamping the system together. The shaft will be a stainless steel and a push-pull. There will be strips for fixing the wheel axles inside the box. Construction In order to have a wheel that spins at a velocity of 2 rad/s we need 100mm diameter wheel that connected to a 10mm diameter shaft that which passes into the box via the 45o face as shown. The ‘Box of Tricks’ is simply an empty steel container with wall thicknesses of 2mm, so the first thing you need to think about is access to the inside of the box. The beam, starts from the central position as specified in the technical drawing below is to oscillate through on full cycle in and out of the box at a frequency of 1Hz, returning to its start position. It is necessary to create a base for the wheel to spin. However, since the box and shaft are already complete, we only need to get a formula that will favour a square base and constitute the figures reflected by the box’s dimensions in the aquatic equation. Moreover, since the desired base design is square, a quadratic rather than an aquatic equation will serve the purpose better There have been accurate analyses meant to figure out very well the internal structure of a bearing to provide frequencies that is the appropriate for the box. This is meant to reduce the various problems that do arise from the box especially if they have been in use for a long time. During the calculation of the various frequencies used in the bearings, the calculations do require one to know some basic information that is typically known. For example, the typical information includes the diameter: inner and outer size. However, some manufacturers do change particular internal designs to complicate the specifications. Consequently, the specified bearings sizes are not changed. The diameter ratio of the wheel (d) to the shaft (D) is set at a constant value of 10. Different values of the gap ratio (e/D) and spacing ratio (G/D) are investigated. The effects of the gap ratio and spacing ratio on the spinning. Any quadratic expression can be simplified and presented in the form ax2+bx+c, where a, b and c are constants and a ≠ o. you will notice that in all these cases, (b/2)2 =c. for this expression to be used to find any side of the square base, we must deal with a case where a=1, for instance: In x2 +10x, we must find out what can be added to make it a perfect square. We shall use this relationship to make the expression a perfect square so that we determine the dimensions of the lower support part of the box as shown below. The process of constructing this box of tricks will need the use of precision pillar drill and grinder. Some other items that will be needed are Jigsaw, screwdriver, Router, circular saw, sander, drill bits of 10mm and 15mm, countersink, spanner, paper, pencils, rubber, sharpener, and metre stick. The drilling will help in creating holes on the wooden whereas the grinder will be used cutting or smoothing sharp areas of a metal. The door will cut at one area of box and bushes are welded to the door. The hole will be bore at the bush to fit the front part with diameter of 10mm to ensure that the wheel is centred at the end of the shaft. The internal structure will have a ballrace ring which will hold a flange in the 45o. The bush will be glued to base disc in the box which will have blanks that are cut to fit the system. Before the drilling the disc at the base of the box, marks is made at the centrelines on the drawing to show the sections to be drilled and the paper is mounted on the base disc. The wheel will be connected to the shaft as shown below In order to determine the design for the door of the box, certain features have to be considered. For one, the weight of shaft and wheel that is spinning plus that of the door itself should surpass box is in use. Fixing the wheel in the box- To fix the wheel after construction one will need axles, a fixing strip, a supporting strip and a strip that creates space when the wheel is moving. This means one of the axle from the created door is movable and it is fitted with controlling cables which are supplied with power to act as brakes. Bolts are fixed to spacer strip which has a drilled 10mm diameter also the support strip will have a bold of 10mm to enable it carry the front axle. All axles to the box of tricks are fixed using metal rod that is fixed to support strip and spacer strip. A screw is used to fix the strips together and it also inserted to a hole that is drilled into the rod through the wood. Results To find the magnitude of the radial acceleration for uniform circular motion, first I calculated the change in velocity ∆v for a time interval ∆t in the limit ∆t-0. The velocity keeps the same magnitude but changes direction at a steady rate, equal to the angular velocity .In a time interval ∆t, the velocity v rotates through an angle equal to the angular displacement ∆=. During this time interval, the velocity vector sweeps out an arc of a circle of radius v. In the limit ,the magnitude of becomes equal to the arc length, since a very short arc approaches a straight line. Then =arc length= radius of circle x angle subtended =v= v Acceleration is the rate of change of velocity, so the magnitude of the radial acceleration is 2== =v Velocity and angular velocity are not independent; v = v. It is usually most convenient to write the magnitude of the radial acceleration in terms of one of the other of these two quantities. So we write the radial acceleration in two other equivalent ways using v = v: =r= or r =r When the wheel spins on the axis created at frequency of 1Hz and velocity of 2rad/s and angular displacement of 45o. Then angular displacement is ( D q ) spin = + 2p rad . Since 2 radians is one complete cycle the angular frequency is Angular frequency = 2πf Angular frequency = 2x1= 2 To determine the time the wheel takes stop from moving once begins to be in motion will depend the velocities applied and angular displacement. This is solved by the equation Where and is the beginning velocity and final velocity respectively, while is the angular replacement. Angular acceleration is determined by the change of the beginning velocity and final velocity and is written as As the wheel spins in the box of tricks , it takes a positive direction in the box and the average angular acceleration of wheel in rad/s2 is =( )()() = x 2x () = 0.033 rad/s2 The acceleration of the wheel is 0.033 rad/s2 . it should noted that the wheel will have zero angular acceleration when the velocity is constant however this is not possible when we have one revolution. This written as a = 0 rad/s. In the analysis of the wheel speed and frequency accurate figures have been used to reduce errors. The drawing for the wheel has been labelled to provide the appearance of the wheel in the box. The internal structure of the box gives an allowance for the wheel to revolve without affecting the internal walling of the box. This reduces problems associated with wear and tear during the rotation of the wheel. At the time of in stalling the wheel one was required to know how to calculate frequencies to be used, angular acceleration, velocity and time taken by the wheel to complete one revolution. This has been done in the case above. In the above case the diameter of the wheel played an important role as well as the internal size of the box. At the begging the wheel will start moving with aching speed because of the acceleration however it will reach a point where the acceleration rate will be constant until the velocity is changed. At a point when change in time is equal to zero, change in velocity is not perpendicular to velocity, then the wheel will fit into our box of tricks. Conclusion As we have noticed in the discussion, the design and construction of the box of tricks has more to it than that shape and form. For this electronic devise to function appropriately, it was necessary that all the aspects, especially the dimensions had to be factored in such include types of metals and velocity of spinning. Also important were the mass, weight, volume and velocity of the various elements involved. If any of such requirements was flouted at the initial stages of design and construction materials will go to waste. This is how crucial he task has been. After the direct observing regarding the wheel’s shaft as well as the vibratory motion since most of the time, the immediate source of the vibration of a rotating wheel is the shaft provided. The box provided has supposed measurements that are normally valuable if under definite conditions as wheel normally deploy certain bearings that have general stiffness as well as damping distinctiveness which inadequately do transmit certain shaft vibrations especially to the box of tricks. Consequently, there have been direct observation regarding the shaft of the wheel otherwise known as rotors rather; the rotor is recognized as the more accurate assessing method to determine the condition regarding a rotating wheel. Reference Brigham, E., 1988. The Fast Fourier Transform and Its Applications. Englewood Cliffs, NJ: Prentice-Hall, Inc. Forshoffer, W. 2011. Best Practice Handbook for Rotating Machinery. Manchester: Elsevier Science & Technology. Karniadakis, G. E., & Triantafyllou, G., 1989, Frequency selection and asymptotic states in laminar Wake, Journal of Fluid Mechanics , vol. 199, pp. 441-469. Mcmillan, B. 2004. Rotating machinery: practical solutions to unbalance and misalignment. London: The Fairmont Press, Inc. Norfield, D. 2006. Practical balancing of rotating machinery. London: Elsevier. Read More