CEB Press/Manufacturing Instructions/Controller Box/FeF Liberator Controller

Step 2

Source the electronics. Here is a diagram of the controller box

Here is the complete controller installed:

Electronics Box

Electronics Box

Gross Electronics:

• Electronics Box - local hardware store
• Extension Cord
  • Or house wiring with Female Plug and Male Plug.
• 2 alligator clips for battery connection - auto parts store
• House wiring box (blue box in picture above below the Arduino Shield - hardware store
• Fuse holder - car parts store
• 12v quick connect plugs - 5 pairs - for quick-coupling to solenoids out of controller box - car parts store
• Stranded 5A wire for solenoid connections
• Spade terminals (10) for connection to solenoid terminals
• Underground phone cable - makes very tough connectors for sensors
• Potting compound
• PVC pipe - with 1 end capped
• Stranded Cat 5 wire for sensor connections
• [5] Supermagnets -

Microelectronics:

• [2] Hall Effect Sensors - Sparkfun
• [1] Arduino shield kit - Makerbot
• [1] Arduino - Makerbot
• [2] RepRap PWM Driver Boards

Components for PWM Driver Boards

• [1] Replacement MOSFETS -
• []

Step 3

Shopping list for items which are shipped:

• [1] Arduino breakout shield - $25, Makerbot

Arduino breakout shield components. Solder green parts (left in picture) last, after the black pieces (bottom in picture).

• • Assembly instructions - [1]
• [1] Arduino (Duemilanove) - $30, Makerbot
• [2] Solenoid drivers -$13 ea., Makerbot
  • Assembly instructions - [2].
  • total cost with shipping - $88.25
• [4] MOSFET replacements (see discussion) for solenoid drivers, VNP35N07-E - $3.34, Future Electronics (if not available, search at Octopart) (grate shaker is automated, no sensors needed for it)
  • Notes: The cheaper version recommended by Nophead from RepRap was this [3]. See discussion.
  • Total $25.70 (for 5)
• [2] Hall Effect sensors - $0.95 ea, Sparkfun
  • Total $9.16 (for 5)
• [4] 3/8" V-groove bearings - $7.77 ea, VXB
  • Total $42.47
• [6] Supermagnets - $0.48, Gaussboys
  • Total $11.11 (for 12)

Grand total for electronics, magnets, and bearings - $176.69

• [1] Potting Compound - $22 for 48 oz, Polymer Composites
• Molex connector for powering solenoid drivers - [4]
• [1] Fuse holder - [5]

Step 4

Put together control box and test sensors

• Assemble entire Control Box
  • Blue spacer box - Arduino attached on top with 2 small screws. Slightly slanted attachment to make screw holes fit on blue spacer box
  • Terminal in electrical outlet box cut in half on metal cutoff saw to create + and - terminals
  • Plastic mount on bottom of electrical box was shaved to allow 2 solenoid drivers to fit

• Test Arduino on laptop - for example by blinking Channel 13 output on Duemilanove.

• Test sensors by passing magnets over them. See this sample code.
  • Data Sheet
  • Supply voltage is 5V from the Arduino breakout shield
  • The pins are +,-, OUT reading from top (printed / smaller face)
  • The output is "Open Drain" - this means you need a "pull up" resistor on the output (10K connected to +)
  • This model is "latching" which means it turns on from one pole, and off by the other, remembering its state in the meantime.

Step 5

• Test solenoid valves by attaching power to battery and running this sample code for 2 solenoid channels.
  • Note we can reduce 3 solenoid channels to 2 by running both the shaker motor and the drawer cylinder from the same channel - the shaker is activated at every stroke of the drawer, as there is ample hydraulic fluid flow available in that part of the overall CEB operation cycle.

Step 6

Build sensor and magnet mounts, attach to the machine

Step 7

Mount control box and solenoid valve on the machine

Step 8

Test the entire machine

• Test motion of main cylinder with this code
• Test motion of soil drawer cylinder with this code.
• Test motion of both cylinders, and machine is ready to run.