Revision 35 as of 2011-11-29 21:28:54

Clear message

Aims

  • redo all internal wiring and logic, except the refrigeration parts
  • make the machine more safe by doing things properly and reducing the voltage of exposed components
  • keep the software interface as simple or more simple than before
  • make the buttons on the front of the machine work for dispense
  • make it extensible so things can be added on
  • give the machine a general service where necessary (seals, rust protection, oil)

Draft Bill of Materials

Amount

Item

Use

Model

Unit Cost

Total

7

microswitches

front button switches

http://au.element14.com/honeywell-s-c/v7-1v19e9/micro-switch-pin-plunger-spdt-21a/dp/1796579

$2.16

$15.12

20

microswitches

each slot has double microswitches, there are 10 slots, 0.15N

http://au.element14.com/honeywell-s-c/v7-5f17d8/micro-switch-pin-plunger-spdt-3a/dp/1796593

$3.60

$72

7

5mm round white LED's

replace empty slot globes

http://au.element14.com/vcc-visual-communications-company/vaol-5701wy4/led-5mm-white-1800mcd/dp/1712795

0.616

$6.16

7

resistors

empty slot LED protection

1

stripboard or veroboard

mount LED resistors

10

4 pin connectors

one for each slot actuator unit

1

9 pin connector

interface with distribution box

2

16 pin connectors

base of door connectors (left and right stack)

1

8 pin connector

base of door connector (middle stack)

1

manual drop button

1

PLC

brain

FMD88-10 starter kit, i-STK88-10

$420

1

PLC expansion card

additional IO

EXP1616R

$190

42m

4 core wire, 1mm minimum diameter (to carry 2A)

actuator and empty switch wiring

http://www.thecableconnection.com.au/ 50-metres-Professional-Home-Theatre-in-Wall-Speaker- Cable-4-Core-16-AWG-- --Bi-Wire-cable.html#producttabs

$170.86

8m

9 core wire

front buttons and lights wiring

http://www.ebay.com.au/itm/0-5mm-9-Core-Irrigation-Cable-per-metre-/300341913942

$2.15/m

$17.20

cable ties

cable loom/heatshrink tube/electrical tape

terminal blocks

2

galvanising paint

recoating everything

http://www.diytools.com.au/MOTOSPRAY-Silva-Gal--Pressure-Pack-400g.html

$12

3

110V fan to replace refrigeration fans

Total

Internal PLC IO Requirements

  • 10x24V DC input for can sensing (would it be worth multiplexing this?)
  • 7x24V DC input for front door buttons (ditto with the multiplexing question)
  • 1x24V DC input for manual dispense mode button
  • 10x100V AC relay outputs
  • 7x DC outputs for empty slot display

Process

  • empty the machine and bring it into the clubroom. This means everything won't have to be packed up at the end of the day while we're working on it
  • remove one of the stacks and test a slot actuator to see what it runs off. This determines what hardware we use to drive everything, so we need to know.
  • purchase all required hardware (PLC, wiring, connectors, switches, etc.)
  • write software (state machine based programming implemented in ladder logic, should be quite trivial)

  • wire up on the bench and test
  • service the machine. A can of zinc spraypaint wouldn't go astray on some of the rust spots I think. Check all the seals. Oil what needs oiling. Clean what needs cleaning.
  • install everything into the machine and test

Measured things

  • Can drop process: 400ms on, 500ms off, 660ms on, 300VAC peak-to-peak, 1.8A
  • Wire lengths:
    • Actuator units 0,1,2,3: 80cm actuator to wire harness, 210cm harness to corner of machine door, 40cm up door, 45cm across, 40cm up to terminal block (4-core minimum) (16.6m)
    • Actuator units 4,5: 80cm actuator to wire harness, 170cm harness to corner of machine door, 40cm up door, 45cm across, 40cm up to terminal block (4-core minimum) (7.5m)
    • Actuator units 6,7,8,9: 80cm actuator to wire harness, 140cm harness to corner of machine door, 40cm up door, 45cm across, 40cm up to terminal block (4-core minimum) (13.8m)
    • Buttons: 75cm across front of door, 60cm down edge of door, 45cm across, 40cm up to terminal block (8-core minimum) (2.2m)
    • Lights: 75cm across front of door, 60cm down edge of door, 45cm across, 40cm up to terminal block (8-core minimum) (2.2m)