Technicians’ Notes

Apparaturs list

The items below are required for the construction of the Beagle 2 lander model:

  • 1 force sensor FSG15N1A (Farnel InOne 721-6671)
  • 1 force sensor mounting bracket (Farnel InOne 721-6683)
  • Plastic downpiep (Marley 68 mm RPH252BX)
  • Quickset cement
  • 2 4 mm socket red (JPR 705-230)
  • 2 4 mm socket black (JPR 705-231)
  • 1 1N4001 diode (JPR 1N4001)
  • 1 PP3 battery clip (JPR 440-006)
  • 1 9 V PP3 alkaline battery*
  • 1 4 mm plug red (JPR 706-197)
  • 1 4 mm plug black (JPR 706-198)
  • 1 socket housing 4-way (JPR 710-604)
  • Crimp terminals (JPR 710-660)
  • Thin connecting wire
  • Small screw eye
  • Small Plastiplug
  • Terry clip to fit PP3 battery
  • Dowelling to fit retort stand boss
  • Thin wooden or plastic rod to anchor string
  • Styrene sheet 2 mm * 10 cm * 10 cm (W Hobby or local model shop)
  • string
  • screws
  • yellow paint

* A supply voltage of between 10V dc and 12V dc maximum is specified but a 9 V PP3 alkaline battery was found to work OK.

Construction method

Saw off two lengths of plastic downpipe 2.5 cm and 3.5 cm in length to make the model moulds. Put a little oil or soap solution around the insides of the moulds. Place these in a tray, pour in quickset cement and leave to dry.

Beagle 2 model

Figure 1: Beagle 2 model

Release the model from the moulds by sawing carefully through the plastic sides at one point. Drill holes in the cement cylinders as shown in Figure 1 and paint the cylinders yellow. Fit a small Plastiplug into the back/topside of each and fit a screw eye into these. Fit another small Plastiplug into the hole with which to attach the sensor mounting bracket, screw the bracket in place with the force sensor. Crimp four thin insulated leads of length 50 cm each to the crimp terminals and inset the latter into the socket housing. Pass the wires through the outer hole in the cement cylinder and through the screw eye. Push the socket housing onto the force sensor.

Beagle 2 sensor platform

Figure 2: Sensor platform

Construct the sensor platform as shown in Figure 2 above and solder the leads to the appropriate sockets, incorporating a 1N4001 diode into the +9 V battery line with its band (cathode end) furthest from the red 4 mm socket. This diode will protect against reverse battery connections to the force sensor. Figure 3 below shows the connections to the force sensor.

force sensor

Figure 3: Connections to the force sensor

Finally, tie a 40 cm length of string to the screw eyes and pass this through the platform’s central hole and tie to a thin plastic or wood rod to anchor it. Screw the Terry Clip in place on the underside of the platform. Connect a red and black 4mm plug, as appropriate, to the PP3 battery clip.

UK suppliers

Farnell InOne
Canal Road
Leeds
LS12 2TU
Tel: 0870 1200 200
Web: www.farnell.com

W Hobby Limited
Knight’s Hill Square
London SE27 0HH
Tel: 020 8761 4244
Web: www.hobby.uk.com

JPR Electronics Ltd
Unit 4, Circle Business Centre
Blackburn Road
Houghton Regis
Dunstable
Tel: 01582 470000
Web: www.jprelec.co.uk

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