davidbuckley.net
home  >  Bambino  >  28 January 2012

Bambino Build by David Buckley

Developer build instructions

  • Revisions

    Bambino parts should be lightly sanded all over - it makes Bambino nicer to handle.

    Parts can be glued together using -
    - White woodworking glue - (PVA glue)
    - Superglue (Cyanoacrylate)
    - Hot melt glue
    Practise assembling parts before gluing.

    On some of the servos the horn can go on too far and binds against the body. If so sandpaper or file the horn so it doesn't touch the servo body.

    The H plate at the front of the body is for a Devantec SRF05 Ultrasonic Ranger.
    The pads at the bottom of the PCB suit the SRF05, join with wire links.

    There are pads on the LHS for a three pin header for a compass module.

    The SRF05 and compass probably need 4AA cells. Two 2AA cell holders will fit vertically one on each body side.
    The two mid voltage wires can be commoned in the centre terminal of the power connector.

    Bambino can be built and used without using a computer.
    It can be setup from the hand-controller, see below, and moves can be taught from the hand-controller, see Bambino Setup and Use.

    To program Bambino you will need a programming cable.
    Download the PicAxe programming Editor from www.picaxe.com
    The connections for the programming cable are in Manual-1 page 8.
    or see # Download Circuit.
    The manuals are under the Help tab in the Editor.
    No level shifters are required, just a straight connection to a PC serial port, or a USB to serial-port adapter. PicAxe sell suitable serial-port or USB programming cables.

    If desired the plywood can be painted either before or after assembly.
    Water colours work well, see
    http://davidbuckley.net/MAi/Ambler.htm and
    http://davidbuckley.net/MAi/Ambler_files/ClassroomKits.htm

    Body

    The plywood servo-mounting plates have two holes so it doesn't matter which way round they are fitted.

    Servos

    Insert the rubber grommets in the servo mounting flanges.
    Then insert the brass ferules into the grommets so the flange of the ferule will be against the plywood mounting plate.
    Thread the servo wires through the middle hole on each side.
    The bottom servo goes to the Left side and the Back servo goes to the Right side.
    Screw the servos to the mounting plates with the servo screws.
    Screw up until the head of the screw is against the end of the ferule.

    Legs

    Make two Legs, left and right handed.
    A Left Leg is shown viewed from the inside, the front of the leg is at the right..

    Feet

    Make two Feet, left and right handed. A Left Foot is shown looking at the front of the foot.
    Glue the part with "Bambino" at the front of the right foot.

    Leg/Foot assembly
    Fasten the legs to the feet using two of the longer screws for each foot.
    Insert the screws through the ankle plates and into the leg.
    Screw the back one in first, nip it up then back it off one half turn.
    Screw in the front one so the head is nearly touching the ankle plate and the foot is free to pivot.

    Battery Box
    Stick the battery box on the top plate using the stickypads supplied.
    The box should go on so the long way is front to back.
    The wire exit should be at the back and obviously the lid should be on top.
    Make sure the box is not further forward than the front edge of the top plate otherwise the programming cable will not fit in the socket.

    Circuit Board

    Screw the circuit board to the body using four of the shorter screws.

    The battery box wires go to the three terminal screw connector on the circuit board.
    Black to the outside, Red to the inside and the centre terminal is not used.

    Plug the servo connectors onto the 3-pin header plugs on the circuit board.
    The bottom servo goes to the Left connector and the Back servo goes to the Right connector.
    In each case the brown wire goes to the outside of the board and the orange wire to the inside.

    Rear Leg-Link

    Attach a 'Cross' servo-horn to the rear leg link, green in the drawing.
    Use four of the shorter screws.
    The screws although not shown go through the plywood and into the horn.

    Front Leg-Links

    Using two of the longer screws attach the front leg-links.
    The screws go up through the link and into the body.
    Nip them up and back off one half turn so the links are free to turn.
    At one end of each link the hole is nearer the end, that end should be fastened to the body.

    Centre the Servos
    Fit 3 AA cells and
    use program #28 which is pre-loaded and press the Power button to put Bambino into sleep-mode.
    In sleep-mode Bambino stands with the feet together and the servos are at their mid position.

    Press on the Servo Horns
    Press the servo-horn on the Rear Leg-Link onto the servo so the legs will be even.
    Note that due to the splines on the output shaft it may not be possible to have it exactly centred at this stage.
    Fasten the Horns to the Servos using the small screw provided with the servo.
    Caution - do not overtighten these screws, they will strip the thread and fall out.
    If that happens use one of the shorter screws holding on the Circuit Board.

    Attach Legs
    Screw the Front Leg Links to the Legs, again nip up the screws then back off one half turn.
    Screw the Rear Leg-Link to the legs in the same way.

    Tilt Arms
    Screw the tilt arms to the straight servo-horn using two of the short screws.
    Screw until the point of the screw can just be felt coming through the other side of the horn.
    Note to which side of the horn the tilt arms are fitted.
    Screw the tilt arms to the feet in the same way but use two of the longer screws.
    The point of the screw should just be felt as it comes through the ankle plate.

    Press the horn onto the servo so the feet are level.
    Note that due to the splines on the output shaft it may not be possible to have it exactly centred at this stage.

    Fine adjust the centre point of the servos
    This can be done through the IR-handset. See Setting the Servos
    or
    Centre the servos using program #4.
    The calibrated position are stored in the microcontroller.

    How Bambino should look


    Note the feet are not flat. The outer edges are slightly down.

    Bambino is now ready for use


    [page top]
    Download Circuit

    Note the connections to the stereo jack are different from standard.
    The tip is Ground=0v
    'b' goes to Tx on the PC, usually pin-3 on a PC serial port D9-male connector
    'c' goes to Rx on the PC, usually pin-2 on a PC serial port D9-male connector

    To make a lead you will need a 3.5mm Stereo-Jack and a D9-female connector.
    Wire the Jack-tip to DB-9-pin-5, Jack-'b' to DB-9-pin-3, Jack-'c' to DB-9-pin-2


    [page top]
    Revisions
    alpha PCBs
    Phototransistor load resistors - 100K
    All Whisker LEDs resistors - 82R
    GroundwhiskerLEDs uncommoned.
    GwhiskerLedL_=c.3
    GwhiskerLedR_=b.3 new connection