Lifting Bridge   Recently updated !


Lifting Bridge.

Posted on April  14th, 2009 by

 

lifting bridge

 

Note: Once
finished, models shouldn’t be used as toys in the commercial
sense of the word. They are an educational tool, suitable
for the classroom

 

1.) Technical Information

 Activities to be undertaken

  •  Interpretation of diagrams and plans
  •  Construction of various structures
  •  The construction and adjustment of a reduction
    motor
  •  Assembly of the electronics involved
  •  Mechanical assembly
  • Required tools (not included in the
    kit)


  • Set square
  •  Saw
  •  Files
  •  Vertical drill and drill bits of 3 and 4mm
  •  Screwdriver
  •  M3 and M4 keys
  •  Scissors
  •  Pliers
  •  Soldering iron and solder
  •  White glue and glue gun
  •  1.5V batteries
  • 1.3 Measurements

    600x320x150mm

    1.4 Objective

    The construction of the bridge will allow the students to
    learn how to resolve two problems-How to ensure the safe
    passage of people and vehicles over the bridge-How to equip
    the bridge to allow the passage of boats taller than the
    bridge

    2.1. Material provided

     

    Material Number Measurements   Piece Picture

    Plywood

    1 10x140x498 mm Base lifting bridge material 1
    2 Pine strip 1 10x50x300 2x10x50x1002x10x50x50
    3 Pine strip 4 10x75x80
    4 Pine strip 1 10x50x350
    5 Plywood 1 5x70x250 1x5x70x601x5x70x1102x5x10x45
    6 Pine strip 4 10x15x325 1x10x15x3101x10x15x3001x10x15x160

    1x10x15x150

    2x10x15x90

    3x10x15x40

    7 Wooden Pulley 2 Ø10×10 mm
    8 Pine strip 3 5x10x250 1x5x10x1151x5x10x903x5x10x80

    1x5x10x70

    1x5x10x20

    3x5x10x15

    9 Rods 12 Ø3×500 mm
    10 Cotton thread 1 2 meters
    11 Metal rod 1 Ø3×95 mm
    12 Retention rings 6 Ø3
    13 Metal rods 2 Ø3 x 70 mm
    14 Mounting blocks 2 30×53 mm
    15 PVC fittings 2 Ø7 x
    25 mm
    Reducing motor
    16 Brass fitting 1 Ø4 x
    25 mm
    Reducing motor
    17 Motor 1 Ø21 x
    25 mm
    18 Double toothed wheel 4 50/10 teeth 3 whites, 1 red

     

    2.2 Material provided

     

    Material Number Measurements Picture
    19 Pinion 1 10 teeth lifting bridge materials 2
    20  strips connections 2 12 connections
    21 LED 2 Ø 5mm
    red
    22 LED 2 Ø 5
    mm green
    23 Resistors 2 130
    Ω
    24 Limit switches 2 250 V/5A
    25 Sliding switch 1 6 contacts
    27 Electric wire 1 10 m
    28  screw bolt 2 M4 x 30 mm
    29 Nut 4 M4
    30 Washer 6 M6
    31 screw bolt 2 M3 x 35 mm
    32 screw bolt 1 M3 x 20 mm
    33 Nuts 4 M3
    34 Washer 8 M3
    35 eyebolt 4 Ø 3 x 10 mm
    36 Screws 6 DIN 7981
    37 Screw 8 DIN 96
    38 Screw 2 DIN 7981
    39 Battery holder 1 2 (1,5 V) battery
    40 Battery holder connector 1

     

    3. Construction

    Before starting to make the bridge it is important to
    familiarise yourself with the general plans of the bridge
    (figures 27/28) and the diagram of the electrical layout.

    Construction phases

    3.1. The construction of the moving section of the bridge
    3.2 The construction of the bridge

    pillars
    3.3 The construction of the barrier3.4 The
    construction of the reduction motor3.5 The assembly of the
    different components3.6 Electrical installation

    3.1 The construction of the the moving
    section of the bridge

    3.1.1 Cut two 80 x 50 x 10 mm pieces and two 50 x 50 x 10
    mm pieces of wood from the piece of wood measuring 300 x 50
    x 10 mm (2), using a saw. The two pieces 80 x 50 x 10 mm are
    going to be used for the bridge pillars

    image4

    image 5
    3.1.2 Mark the centre of the two 50 x 50 x10 mm pieces,
    obtained in point 3.1.1, and round them off as shown in
    figure 2. These pieces will serve as the base for the moving
    section of the bridge.

    3.1.3 Drill a hole through the two pieces at the same,
    using a Ø3mm drill piece, at the
    point indicated in figure 2.

    Note: Put the pieces on on top of the other, fix
    them together with adhesive tape and drill both holes at the
    same time. The Ø 3 x 95 mm shaft
    (11) will be passed through this hole later. 3.1.4 Make a
    2.5mm wide and 55mm long groove in both sides of the 10 x 50
    x 350 mm strip of wood (4), as shown in figure 3.
    figure 3

    figure 3
    3.1.5 Glue the two perforated 50 x 50 x10 mm pieces onto the
    walkway piece of the bridge (4), as shown in figure 3. 3.1.6
    Cut the following pieces, indicated in figure 4, from the
    two large pieces (8) of 500 x 10 x 5 mm. 1 piece of 115 x 10
    x 5 mm 1 piece of 90 x 10 x 5 mm 3 pieces of 80 x 10 x 5 mm
    1 piece of 70 x 10 x 5 mm 3 pieces of 15 x 10 x 5 mm
    figure 4
    3.1.7 Make a slit, 1mm wide and 5mm long, in both ends of
    the 115 x 10 x 5 mm piece of wood (obtained in point 3.1.6),
    as shown in figure 5.

    figure 5

    3.1.8 Make a piece like the one shown in figure 6 from
    one of the 15 x 10 x 5 mm pieces (obtained in point 3.1.6).
    Then glue this piece to the end of a 80 x10 x 5 mm piece of
    wood (from point 3.1.6) in the position indicated in figure
    6.
    figure 6

    3.1.9 Stick the 115 x 10 x 5 mm piece from point 3.1.7,
    with the the piece of 80 x 10 x 5 mm, obtained in point
    3.1.8, and the 80 x 10 x 5 mm strips onto the walkway of the
    bridge, as shown in figure 7. Fix an M4 washer (30) to the
    outside face, over the hole, as shown in figure 7.
    figure 7
    3.1.10 Make the frame and rails of the walkway of the bridge
    using the rods (9) and the template in figure 29, on the
    scale 1:1. Make one side first, then the other and glue them
    to the underside of the walkway. Then fix the crossbeams (a)
    between both frames and the diagonals (b) to each end
    triangulating the end of the structures, as shown in figure
    8.

    figure 8 bridge

    3.1.11 Make the two rails by cutting eleven short pieces
    and one long piece for each side from the rod (9). Space the
    short rods equally, as shown in figure 8. Stick the whole
    together and glue to the bridge. Note: Assure
    yourself that neither the frame nor the rails exceed the
    limits defined in figure 8 as this could cause problems with
    the raising and lowering of the bridge.

    3.2 The construction of the bridge
    supports

    3.2.1 With care, cut out a hole in one of the 80 x 75 x
    10 mm pieces with a coping saw, as shown in figure 9. This
    is where the sliding switch will be placed later, to connect
    and disconnect the current. Take a second 80 x 75 x10 mm
    piece and bevel the corners of both pieces at the angle
    shown and make a hole in the same position in both with a
    3mm drill, as shown in figure 9.

    Note: Put the two pieces one on top of the other,
    join them together with adhesive tape and do the beveling
    and perforating in both at the same time.

    image 9

    3.2.2 Stick the two large 80 x 75 x 10 mm pieces with the
    Ø 10 mm pieces obtained in point 3.1.1, as shown in figure 10.
    Do the same with the two 80 x 75 x 10 mm pieces without
    holes and another 75 x 50 x 10 mm piece.

    figure 10

    3.2.3 Stick the first piece (the one with holes),
    obtained in point 3.2.2, to the large 495 x 140 x 10 mm (1)
    piece, to act as a bridge support, as shown in figure 11.
    figure 11
    3.2.4 Place the moving part of the bridge (from point 3.1)
    between the two bridge supports and fix them in place using
    the Ø 3 x 95mm metal shaft (11).
    Make sure it can move. On the right, the board must be a
    little lower than the horizontal. If necessary, file the
    support down a little at the points where it supports the
    walkway of the bridge. See figure 12. Fix the rod in place
    with the washer (12). See figure 12 Attach the second
    support (without holes) to the end of the base. Make sure
    there is a gap of 0.5 and 1 mm between the support and the
    walkway.
    figure 12

    Dictionary:::

    pillars:  vertical support; a column