Week 18 - Project Development

"Complete your final project, tracking your progress."

What tasks have been completed?

Completed AND Not Completed

  1. [Completed] Game Box 
    1. The Game Box is constructed out 15mmX15mmX1000mm extruded aluminum stock from a company called Openbeam.  The owner is great and helped me setup a classroom right after his kickstarter campaign.  The Openbeam stock is connected using his "T" and "L" fittings and standard 3mm hardware.  The box has VEX rails to serve as tracks for the steel rods which serve as the X and Y axises. The vex also uses the same connecting bolts.
  2. [Completed]Puzzle Grid
    1. The puzzle grid is a five sided box made with Openbeam stock and hardware with Lexan.  The Lexan is mounted in the grooves of the Openbeam stock.  The Lexan has holes driled at 20mm intervals to form a grid that will accept the insertion of puzzle pieces which extend under the top of the Lexan going toward the plastic netting.  This allows the user to change the obstacles for a variety of challenges.
  3. [Completed] Stepper control bar linkage boxes (qty 2)
    1. These boxes serve as the connector between the stepper motor drive shafts and drive shaft nut and the steel rods for both X and Y. These are custom designs and 3d printed in PLA.  The X and Y boxes are not identical due to spacing in tracks.
      1. Cube workflow:
        1. Design part and export as .STL file.
        2. Open Cubify design software and import file.
        3. jClick the "heal" button on the software.
        4. Under settings: set to PLA, set to medium density for Cube 2, set to no rafts or supports 
        5. Click on "Upload" button to export and save t thumb drive
    2. X and Y axis linkage boxes
      1. V0.2 X axis linkage box on Thingiverse here. 
      2. V0.2 Y axis linkage box on Thingiverse here. 
      3. [UPDATE] Due to the nature of the blocks and linkages interferring with chassis connecting hardware, the stepper control plate had slides instead of holes designed into the plate so the plate can slide up and down to tune the linkage blocks.
  4. [Completed] Magnet central mount: This box connects the two steel rods and serves as a mounting point for the electro magnet.  This also allows the use of bearings to hold the steel rods.  Part on Thingiverse.
  5. [Completed] Rod pillow block: this connects on the opposite end of the guide rod to keep it level across the Game Box. Part on Thingiverse.
  1. [Completed] Stepper motor mounting plate
    1. A component is available from Openbeam to mount NEMA17 stepper motors.  However, the design did not quite meet my specification for mounting the motors in a hybrid Openbeam and VEX infrastructure. I designed custom plates and printed them out on a Cubify 3D printer.  The printing ended up taking quite a bit of time as I attempted to make a new 3d printer operational (The Buccaneer by Pirate 3D), but it would not even load filament out of the box.  The Cube 1 is a fairly solid printer that is dependable…usually.  We will see if the PLA plates will hold up. 
      1. Cube settings
        1. Print 1 set with raft enabled and at medium (strong) density.
        2. Probably need to remove the raft since this is a flat piece and added thickness.
    2. These should probably be machined out aluminum plate for strength.  The Shapeoko just arrived and is 6-8 hours of build time.  Time that is not currently available to meet deadlines.
    3. Nema 17 stepper motor mounting plate V0.2 available on Thingiverse here
  1. [Completed] Fabduino - I used a Fabduino and the Arduino IDE to control the motors, switches, and magnet. 
  2. [In progress] Add limit switches to restrict range of motion

What has worked and What has not worked?

  1. Moved through three versions of the stepper mounting plate.  V0.3 is current build being used.
  2. The mounting plate made of PLA is working very well and seems strong enough.
  3. The control rods tend to bind up some times making it tough to control
  4. The code is working great!  The control linkages printed on the 3D printer have very nice tolerances and are holding up great.
  5. The inverted puzzle grid needs to be cut with a CNC to be very precise and the pieces do not stay in place at the moment.

What questions need to be resolved?

  1. How do I get a magnetic embedded ball to levitate?  
  2. What code is needed to control this?
  3. What sensors do I use to sense the fields and adjust the magnets?

What skills learned in the course were used to accomplish this:
Electronics production: Fabduino is the central control for user input via an analog joystick to output on two NEMA 17 stepper motors

  1. Electronics production: Eagle, FAB ISP to burn the bootloader onto the Fabduino
  2. Programming with the Arduino IDE and Text editor
  3. Inputs: Analog joystick with incoporated switch, LEDs
  4. Outputs: Stepper motors
  5. CAD design: intial design using paper and pencil and then AI and TinkerCad for multiple areas
  6. 3D printing: the X and Y axis control rods connecting to the Stepper screw rods requires a custom part
  7. Laser cutter: design of case and control mounting board (not in prototype, future enhancement)

What have I learned?

  1. How to code with the Arduino IDE.
  2. How to fabricate boards
  3. How to bring multiple devices together in harmony with a user interface
  4. How to manage time
  5. How to plan for the unexpected by having multiple pathways to success.

© m.t.pearson 2014