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Final Project - mostly done

MODULAR ROBOTICS MAZE

Problem description

I work in the Robomania section at our National Science Centre. We run robotics demonstrations, workshops, camps and clubs. One of the best kits for teaching robotics is the Lego Mindstorm EV3 kit or Lego SPike Prime kit and these kits are the main focus of allot of our programs. One of our most useful challenges is getting students to build and program a robot to solve a maze and pass through it. The current maze we use has some major problems:

  • The maze itself is bulky and heavy, making it difficult to transport when we run the activity at remote locations

  • The maze design is fixed. We give students free range to use whatever programming techniques they want to “solve” the maze. Rather than come up with an intelligent program that can solve a variety of maze configurations, some students use a brute force technique (e.g. programming the robot to go 10cm forward, then turn left 90°, then 30cm forward, turn 90° right......). This requires a lot less thought about the robots algorithm.

  • Difficulty is fixed because the maze is fixed. When we encounter particularly talented students who come up with a working solution quickly, we can’t adjust the mazes diffculty to give them a harder challenge.

  • The maze is a little plain. It’s part of a robotics challenge, so having just a wooden maze with no shiny techy features isn’t as visually enticing as it could be.

Solution

My solution: A modular maze. The details of my solution changed throughout my fab academy journey. But my current design is below.

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  • I plan to use flat square floor panels (0.5m x 0.5m each) with small holes in each corner. The holes will allow me to create small 3D printed brackets that will link the floor panels together and hold them in place. These brackets will also come flush with the surface of the floor panels so they shouldn’t interfere with any robot’s mobility.

  • The maze wall pieces will be flat rectangular panels, all with the same height, but varying lengths so that they can be combined into any maze design we like.

  • To hold the wall pieces in place, I plan to design 3D printed brackets that will grip onto the outside edges of the floor panels and the outer walls. aLl the inner walls will be connected together with a variety of 3D printed brackets on top that will hold them to one another.

Electronics:

  • Because of the mocular design of the maze, the electronic component is also modular. The control board is a development board with pins to easily connect to any breakout boards for input and output.

  • The maze competition is a competition to complete the maze in the fastest time. So the main output from the board will be a screen that will output the robots time.

  • The maze timer will be stopped by the robot crossing the exit of the maze. This will be detected by an ultrasonic distance sensor that will detect when an object passes in front of it.

  • The modular nature of the maze and of the development board means it will be easy to change or add features to the elctronic component of the maze without having to make adjustments to the main maze body or the circuit board itself.

You can see a description of my draft solutions here. There I describe the reasoning behind some of my design choices.

Maze Design

The Maze pieces are broken down into three groups: - Floor and wall pieces. - Connector pieces. - Electronics component.

All MAZE MAIN BODY Design files (zip download)

maze wall and base pieces design

I made the wall and base pieces of the maze out of MDF. This was for a couple of reasons. - It is a realtively inexpensive material, that is readily available. - It is quite strong for its weight. - It is easy to work with and still give a nicely finished end product. - It comes in a wide variety of thicknesses if needed.

Out of the various thicknesses of MDF sheets available to pick from, I chose 6mm thickness as it was the lightest thickness that still had the rigidity I wanted. I measured it’s thickness at 5.77mm.

I designed all the pieces in TinkerCAD. Mainly because it’s web based, easy to use and free. The purpose of this maze project is to give it out freely online as a resource to help all the classrooms and clubs that teach robotics in elementary and high schools. Because of this I wanted to use a program that can allow teachers or students to easily alter the designs of the pieces to meet their exact needs or limitations without too much technical knowhow. TinkerCAD gives a great solution for this.

  1. Base plates xxx

    • Main base plate. These are the pieces that will make up the floor of our maze. They are connected to one another using the 4-way and 2-way joiners (below), with teh 1-way joiner(below) being installed on the final corners for height leveling. The edge clips (below) are used to attach the outer walls to the maze to these base plates. You can use as many base plates as you like to assemble smaller or larger mazes.
    • The Base plates are 500mm x 500mm squares. They are the thickness of whatever material you choose (in our case 6mm MDF). In the 4 corners of each base plate are 10mm cutout circles, the edges of the circles are 10mm from each edge.
    • SVG file: base plate with 10mm holes (download)
    • tinkerCAD share link: base plate 500x500 TinkerCAD
    • 6 base plates after being cut

  2. Wall pieces xxx

connector pieces design

All the clips that hold the wall and base pieces together were 3D printed. I designed the pieces in TinkerCAD as well. In order to be able to assemble the maze in a variety of shapes, I needed a range of connector pieces and a number of each in each design.

The dimensions of the clips had to be designed around the thickness of the MDF I chose (5.77mm). In order to be more versatile, I designed our clips to be flexible, so that it grips the MDF more firmly and can accomodate a slight variation in thicknesses. The design of these clips should work with material from 5.5mm to 6mm thickness.

  1. Base plate 4 way hole joiner.

    • Used to join 4 floor pieces together (in the middle of the maze) where they hold them together.
    • A flat square, 2mm thick, measuring 60mm x 60mm with 4 circular knobs 10mm in diameter and 6mm tall, 10 mm from the centre in each direction. The knobs have a very slight bezel to allow for eisier insertion into base plate holes.
    • STL file: base plate 4 way joiner (download)
    • TinkerCAD share link: 4 knob joiner TinkerCAD
    • Images:

  2. Base plate 2 way hole joiner

    • Used to join 2 floor pieces together (on the sides of the maze) where they hold them together.
    • A flat rectangal, 2mm thick, measuring 30mm x 60mm. With 2 circular knobs 10mm in diameter and 6mm tall, 10 mm from the centre. The knobs have a very slight bezel to allow for eisier insertion into base plate holes.
    • STL file: base plate 2 way joiner (download)
    • TinkerCAD share link: 2 way joiner TinkerCAD
    • Images:

  3. Base plate 1 way hole joiner

    • Used to fill the holes in the corners of the maze, and raise the base plate corners so that all floor pieces are level.
    • A flat square, 2mm thick, measuring 30mm x 30mm. With 1 circular knob in the middle 10mm in diameter and 6mm tall. The knob has a very slight bezel to allow for eisier insertion into base plate hole.
    • STL file: base plate 1 way joiner (download)
    • TinkerCAD share link: 1 way joiner TinkerCAD
    • Images:

  4. Base edge clip for walls xxx

    • Used to clip the wall pieces on the border of the maze to the base floor pieces. Two edge clips per wall piece is fine, but you can use more for extra stability if desired. This is piece is the most complex of the connector pieces.
    • This connector is essentially 2 clamps at 90 degrees to one another.
      • The bottom clamp attaches to the base plate. The underneath section is 60mm long. The top section is 20mm long and angled down 3 degrees to help flex grip the base plate more securely. The top sections is shorter so that it deisrupts the waze surface less. All are 2mm thick.
      • The top clamp points upwards for the wall pieces to be slotted into. The back part of it is 50mm tall and slightly thicker at 3mm thick for more sturdiness. The font part of this clamp is 50mm tall, 2mm thick and angled back 2 degrees to help flex grip the wall pieces.
      • The entire clip is 30mm wide.
      • The widest seperation of each clip arm is 6mm to fit the wall pieces.
    • STL file: base edge clip (download)
    • TinkerCAD share link: edge wall clip TinkerCAD
    • Images:

  5. 2-way wall clip xxx

    • Used to join 2 wall pieces together so that a section of striaght wall is extended.
    • A simple elongated U shape. The clip is 60mm wide and 30mm tall. The “arms” of the clip are all 2mm thick. One “arm” of the clip is angles in 3 degrees to help flex grip the wall pieces more firmly. The widest seperation of each clip arm is 6mm to fit the wall pieces.
    • STL file: 2-way wall clip (download)
    • TinkerCAD share link: 2-way wall clip TinkerCAD
    • Images:

  6. Corner wall clip xxx

    • Used to join 2 wall pieces that come together to form a corner.
    • Essentially shaped like 2 shorter “2-way clips” (35mm long) joined together at 90 degrees. The outer arms of the clip pieces are angled inwards at 3 degrees for better grip on the walls. In order to allow the outer arms of the clip to grip independently, they are seperated from each other by a thin slot 6mm wide. The widest seperation of each clip arm is 6mm to fit the wall pieces. The arms of the clip are all 2mm thick.
    • STL file: corner wall clip (download)
    • TinkerCAD share link: corner wall clip TinkerCAD
    • Images:

  7. 3-way wall clip xxx

    • Used to join 2 or 3 wall pieces together where they form a T-shape.
    • Essentially similar to the corner clip piece, except with an additional clip section added past the slot in the corner clip. The long side of the clip is 60mm wide, with the short side 30mm. There is also a slot seperating the added on corner piece in order to allow the short side’s angled arm to flex while gripping. One side of each “arm” is angled in at 3 degrees to help flex and grip the wall pieces. The widest seperation of each arm side is 6mm to fit the wall pieces. The arms of the clip are all 2mm thick.
    • STL file: 3-way wall clip (download)
    • TinkerCAD share link: 3-way wall clip TinkerCAD
    • Images:

  8. 4-way wall clip xxx

    • Used to join 3 or 4 wall pieces where they meet to form a “+” shape.
    • Essentially shaped like 2 corner pieces joined together at 90 degrees.
      • 3 pairs of the clip arms will have one of the arms angled in at 2 degrees for grip on the wall pieces, with the necessary gaps where arm pieces might meet together in order to allow the arms to flex while gripping.
      • 1 pair of clip arms doesn’t have a gap nor angle so that the entire clip is more rigid. This shouldn’t affect grip since this configuration will most often be used with 3 wall sections, with the wall section that goes through the middle of the “+” configuration already being gripped from its opposite arm pair.
      • Each pair of arms are seperated by a gap of 6mm at their widest. The arms of the clip are all 2mm thick.
    • STL file: 4-way wall clip (download)
    • TinkerCAD share link: 4-way wall clip TinkerCAD
    • Images:

Electronics

MAZE ELECTRONICS Design files(zip download)

The electronics part of the maze is designed to be modular as well. The maze will function fine without this part, but it adds a bit of functionality and allot of cool factor to the final implementation.

I chose the details of my previous electronics assignments so that they each contribute to this final project. The details of each of the component steps can be seen here:

Program

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Making the components

making walls and base

making connectors

Final result

Assembly

video

potential future upgrade

  • connectors for aditional angles on walls
  • decals and signage
  • entrance ramp
  • draw bridge or presure plate for electronics
  • led light strips
  • electronics networked for phone control and results
  • groved wall pieces and base plate for sturdier connections
Last update: December 3, 2024