The design report

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Control surface fabrication 5.9 Ailerons: The aileron parts were cut and labelled. AB glue was used to stick all ribs onto the leading edge webspar. The rear end balsa sheet was then stuck on. It was later discovered that the ailerons wouldn’t fit into the slot in the wing. The mistake in the CAD model was that the ailerons were flush with the wing when placed in the slot. However, in fabrication the sizing wasn’t perfect and this meant that the aileron had to be shortened span wise. This was done easily by cutting 3 mm on each edge of the front webspar and re-gluing the last rib. Elevator: The elevator ribs were first slotted into the front plate and glued on using super glue. The servo plate was slotted in before attaching the centre rib. The 1mm balsa sheet was the attached to the rear end of the elevator for the skin. The ‘elevator servo part’ was then attached on to the plate. The skin was added. The elevator got damaged while adding the skin. Hence the backup flat plate was used as the elevator for the aircraft. Rudder: The fabrication process of the rudder is exactly the same as the vertical tail. After fabrication, the control surfaces were attached to the aircraft using tape. Assembly and test 5.10 The first task which had to be undertaken on the day was the assembly of the aircraft. This was necessary due to the fact that the aircraft had to be dismantled for transportation. In order for the aircraft to be unassembled, several elements needed to be added to the design of the plane. Firstly, the wing and horizontal tail plane had to be removable from the fuselage, resulting in four separate components for transportation; the two fuselages, the wing and the horizontal tail. This meant that these components had to be attached with screws only; no glue could be used when joining them, as it would have no time to dry on site. Hence, rather than using glue, a more innovative solution had to be found to securely attach the components. This was as follows: The wing had four ribs which protruded downwards, two of which went into each fuselage, where a screw went through both ribs as well as a block fixed inside the fuselage, appending the wing and the fuselage together. As well as this, 4 screws projected upwards through the top of the fuselage and bottom of the wing and fastened inside the wing, further strengthening the connection between the wing and the twin fuselages. It was also necessary to connect the horizontal tail to both fuselages. This was again done using screws. Two screws were connected through blocks which were previously attached inside the fuselage. The horizontal tail could then be placed on top and slotted onto these screws. The pod was connected in a similar way to the fuselages, with two ribs extended downwards, and then two large screws going all the way through both
ibs as well as predetermined screw holes in the fuselage. It was decided that as the vertical tails were comparatively small relative to the rest of the components, it would not be compulsory to disconnect them for transport. Hence the vertical tails were glued and attached to the fuselages prior to the test flight day. Another adjustment to the design of the aircraft essential for the dismantlement was the necessary discontinuity of the wires within the aircraft. The wires between the fuselages, wing and horizontal tail had to be able to easily connect and disconnect at a point so as to allow each component to be transported independently. This meant that on assembly, the wires within the wing had to be pulled down between a hole in the bottom of the wing and top of fuselage, and then connected with their fuselage counterparts. Similarly, wires protruding from the fuselage were connected to their counterparts on the horizontal tail. The task of attaching the two fuselages to the wing and the horizontal tail plane, and connecting all the necessary wires was in theory a relatively simple task, which had on all previous occasions been performed in less than ten minutes. However, on the day of the flight tests, various complications arose which hindered the speed of the assembly. The first such complication occurred as the left fuselage was being attached to the wing. Each fuselage was attached to the wing using five screws. So as not to lose the nuts involved in this procedure, these had been screwed onto the screws protruding from the fuselage while it was separated from the wing. This first problem arose due to the fact that while trying to find an innovative solution using super glue, the team had inadvertently glued several nuts and screws together. This led to an excruciating 10 minutes in which the team wrestled to remove the super glued nuts. After overcoming this initial issue, assembly was continued. However, after both fuselages had been attached to the wing, it was noticed that one of the wires in the left fuselage had wrapped itself around a rib in the wing, and was caught between the wing and the fuselage. This meant that the left fuselage had to be completely removed from the wing to untangle the wire. This wasted another few minutes, and contributed to the fact that the assembly took almost twice as long as expected. The final task performed pre-flight was the connection of the electronics, and the subsequent checking of the control surfaces and motors. This was performed without any glitches. Measurement of Weight and CG location 5.11 Part Conceptual design phase using formulae (kg) CATIA (kg) 0.38311494 After Fabrication (kg) Wing 0.42756 2 1.080 Fuselage 0.803238976 0.8372 1.230+1.210=2.44 Horizontal tail 0.076920509 0.08195874 2 0.215 Vertical Tail 0.10029 0.0572 Landing gear 0.251998638 0.25 Propeller 0.1 0.1 Total Weight 1.959 1.7094 3.73
Page 1 and 2:
EP-UAV Project 2009 iSpy Kate Rietd
Page 3 and 4:
Preliminary and Detailed Design 4 S
Page 5 and 6:
Executive Summary 1 iSpy is a twin
Page 7 and 8:
Design Requirements and Objectives
Page 9 and 10: Initial Sizing 3.1.2 Estimating air
Page 11 and 12: Airfoil design 3.1.4 Wing: Before t
Page 13 and 14: Tail: A symmetric airfoil with a th
Page 15: Empennage design 3.1.6 The dimensio
Page 19 and 20: Pod Layout 3.1.9 The pod of the air
Page 21: Weight estimation and Centre of Gra
Page 26 and 27: Figure 3.2.303 - Stability axis der
Page 30 and 31: CAD definition of the concept 3.2.5
Page 32 and 33: Figure 3.2.505: The vertical tail F
Page 34 and 35: Preliminary and Detailed Design 4 S
Page 36 and 37: Figure 4.1.109 Figure 4.1.110 The c
Page 38 and 39: Material type was chosen for each c
Page 40 and 41: The nose section of the fuselage co
Page 42 and 43: This part of the fuselage is the mo
Page 44 and 45: Empennage structure 4.1.3 Prelimina
Page 46 and 47: An ‘L’ shaped support was also
Page 48 and 49: Landing gear 4.1.5 Initial stages o
Page 50 and 51: Pod Structure 4.1.7 Figure 4.1.701-
Page 52 and 53: Fuselage fabrication 5.2 Since ther
Page 54 and 55: The servo holder plates in front of
Page 56 and 57: Landing gear fabrication 5.5 The de
Page 58 and 59: Fabrication of Pod 5.6 Like the fus
Page 62 and 63: Note: The weights taken after fabri
Page 64 and 65: It was here that the first problem
Page 66 and 67: Flight Test 6.2 The flight test aim
Page 68 and 69: Appendix 7 Appendix A - AVL files i
Page 70 and 71: TRANSLATE -0.450 0.384 0.00 # BFIL
Page 72 and 73: CLARK YM-15 - Re = 250000 Alfa Cl C
Page 74 and 75: Appendix C - Preparation of materia
Page 76 and 77: Appendix D - Control surface sizing
Page 82 and 83: Conceptual Design Preliminary Desig
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The design report

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