Pneumatic Stations

We will use low-pressure pneumatic actuation for a number of experiments and projects in the course. This includes a portable air compressor, several manually operated valve blocks, and a computer-controlled valve set.

This documentation is minimal but hopefully can provide a starting point for setting up and operating the lab setup.

Compressor Checklist

The compressor is a California Air Tools 10020C.

Checklist:

  1. Plugged into wall socket.

  2. Red power switch in On position. Note that the compressor motor will only actually run when the tank pressure becomes low and stay on until the tank pressure reaches the upper limit.

  3. The left gauge will read between 90 PSI and 120 PSI tank pressure.

  4. The right gauge should read 20 to 30 PSI regulated pressure. If it is above or below this point, please use the red knob to adjust to the correct operating range.

  5. One or more devices can be attached to the two outputs. These are ‘industrial’ shape quick connects; to attach one, simply press the connecting plug firmly into the socket. To disconnect, pull back on the sleeve surrounding the socket. The plug will pop free but the connector will shut off the air flow.

  6. When done, please turn the red power switch to the Off position. Please note that the switch knob wobbles, and it takes a firm twist to seat properly.

Manual Valve Manifold Checklist

The manual valve manifold is a black aluminum manifold block with a low-pressure regulator at one end and four diverting valves. The regulator is attached to blue high-pressure tubing bringing air from the compressor. The diverter valves each have a low-pressure Luer lock socket to connect to your project.

Checklist:

  1. Each manifold has a shutoff valve at the quick connect. To open this ball valve, align the handle with the tubing.

  2. With all the gray plastic diverter valve handles in the middle closed position, the low-pressure regulator should read 2 PSI. Please note that the full range on the gauge is 30 PSI; 2 PSI moves the needle just a small amount.

  3. If the pressure is too high or low, the regulator can be adjusted by pulling out the black cap, twisting it according to the labeled directions, and pushing it back in.

  4. Each diverter valve has three positions: the low position will emit air, the middle position will hold, and the upper position will release air.

  5. The 2 PSI setting is conservatively safe for the 6-inch polyethylene bag material, but may be slow to fill large chambers. If your project requires a different pressure, the regulator may be adjusted over a 1 to 10 PSI range.

  6. When done, please close the ball valve at the source, the handle should be perpendicular to the tubing.

Computer Valve Station Checklist

The computer-controlled valve system has the following parts:

  1. A Linux workstation, ideate-ws-01.

  2. An Akai MPD218 MIDI drum pad.

  3. A valve rack with the following:

    1. Long blue high-pressure supply tube with quick-connect and ball valve.

    2. Low-pressure regulator.

    3. Eight fill-empty manifolds with two valves each.

    4. Two Arduinos with ULN2803 driver shields (one per 8 valves).

    5. 12VDC power supply for the valves.

    6. USB hub to connect the computer to the Arduinos.

Checklist:

  1. The shutoff valve and regulator control instructions are the same as for the manual manifold, please see above.

  2. The 12V valve power supply is plugged into the wall; the USB hub is plugged into the computer.

  3. The computer uses a common account: please log in as user kf. The password will be discussed in class. This account only works directly from the console.

  1. The Config tab shows the current devices, which are preconfigured:

    1. MIDI: MPD218:MPD218 MIDI 1 24:0

    2. Arduino 1: ttyACM0

    3. Arduino 2: ttyACM1

  2. The MPD218 drum pad shows A for the control bank and A for the pad bank. The adjacent CTRL BANK and PAD BANK buttons will cycle through the A/B/C states for each LED.

  3. The MPD218 is in Program 8 mode (PolyPads): when holding down the Prog Select button, PAD8 should light up. If not, holding Prog Select and tapping PAD8 will set this mode.

  4. The Python valves1 program uses the sixteen drum pads in pairs to control the pneumatic outputs. The front row is ‘fill’ for the bottom set of outputs, the next is ‘empty’ for the bottom set, then the rear two rows are fill and empty for the upper set.

  5. When done, please close the valves1 application and shut off the supply air using the ball valve at the compressor connection.