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Bambino Build by David Buckley

Developer build instructions

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 the horn screw is a short black one then sandpaper or file the horn so it doesn't touch the servo body, if the horn screw is a newer chrome plated longer one then leave the screw a little loose so it doesn't press the horn against the servo body.

The H plate at the front of the body is for a Devantec SRF05 Ultrasonic Ranger or the Chinese HC-SR04.
The pads at the bottom of the PCB suit the SRF05, join with wire links or use the plug and socket.
The HC-SR04 connects at the back of the PCB with a cable.

There are pads on the LHS for a three pin header for a Compass module, another Servo, other sensors or Serial communication.

The SRF05 and HC-SR04 will work from 3 AA cells but the compass probably needs 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 ferrules into the grommets so the flange of the ferrule 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 ferrule.

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.

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.

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

One end of each link has flats the other is round, the end with flats should be fastened to the body.
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.

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


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Bill of Materials
Name Type Supplier Quantity
Wooden parts Bambino futurelab3d.com 1
Servos HK15148 Analog Servo 17g / 2.5kg / 0.14s Hobby-King 2
Battery box 3 AA cell no switch
or
2 AA cell no switch
Rapid Electronics 18-2912


1

2
Screws short #2 x 1/4 inch, pan head,self tap 6
Screws long #2 x 3/8 inch, pan head,self tap 14

Kit of parts
Name Type Contents Supplier
Bambino Basic wooden parts, servos, 3AA battery-box, screws, no controller futurelab3d.com
Bambino Arduino wooden parts, servos, 2 x 2AA battery-boxes, screws, no controller futurelab3d.com
Bambino PicAxe 20M2 As Basic plus complete circuit board with PicAxe 20M2 controller futurelab3d.com
Bambino PicAxe 20X2 As Basic plus complete circuit board with PicAxe 20X2 controller futurelab3d.com


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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


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Revisions
2013-Jul-15 revised wording re front leg links,
     [early Leg Links with both ends chamfered - the end with the hole nearest the end is the body end, the other is for the leg]
2013-Jul-15 moved Centre Servos up to before Leg Links.
2013-Apr-06 Added BoM and Kits
2012-Jan-28 Original page
alpha PCBs
Phototransistor load resistors - 100K
All Whisker LEDs resistors - 82R
GroundwhiskerLEDs uncommoned.
GwhiskerLedL_=c.3
GwhiskerLedR_=b.3 new connection