Week 12: Troubleshooting

I'm going to talk about the problems we faced with the physical model and what steps we took to try and overcome the difficulties:

-Gear binding: This is, for now, the biggest problem. Friction caused mainly by the two vertical gears will sometimes prevent the entire mechanism from running smoothly. We will need to make the gears less resistant - for example, we can wrap the teeth with paper to eliminate the problem that exists because of the grooves in the K'Nex pieces. We need to experiment with this.

-Incorrect sizing: The box size was incorrect at a few places, making it uncompliant with the size constraints. However, because the mechanism was small enough, we simply cut the box down to size afterwards. This was easily fixed.

-Wheels colliding with house: Again, we needed to resize the plates by trimming them down. This problem was also easily fixed by trimming both the wheels and the house; both now work properly. However, because the plates became very small, we needed to adjust our design to accommodate the figures. We decided to reduce the number of humans/superheroes from 4 to 2, and instead have two figures "trapped" in the fire and calling out for help. This change is reflected in the final SolidWorks assembly.

-The Crankshaft: This was a difficult problem, but is now solved. Because the crankshaft was at first built in two pieces, the top piece tended to fall through the hole and not work. After much experimentation, we decided to compromise by turning the shaft into one solid pole; while this doesn't give us the exact desired motion, it does allow us to raise and drop the crankshaft flawlessly.

-Bent Box: The bottom of the box seems to be slightly warped. We can attempt to remedy this by inserting another piece of cardboard on the bottom to level out the structure, and the warp will likely be lessened when we install the corner supports.

With only a few pieces left in the physical model to complete, the project is nearing its end. We hope to give a worthy presentation and demo next week!

Week 11: Footage & Images << PART II >>

Brendan: "That's beautiful!"

{Materials}

We have built the mechanism of our physical model entirely out of construction toys called K'NEX. These toys provide us with rods, connectors, and a variety of accessory pieces (i.e. Wheels, Pulleys, Panels, Spacers, Gears, Bricks), varying in different shapes and sizes. Some other common materials we will be using for boxing in the mechanism, and aesthetic purposes and reasons are :

• Cardboard
• Tape
• Paper
  
• Kleenex Tissue
• Bamboo sticks
• Styrofoam balls
• Coloring pencils/pens/paint
  
• Colouring pens/pencils/paint
• Clay
  
  
  

  {Progress}
  

  
  
  
  

  Great news: we have pretty much finished the mechanism earlier today. The remaining issue is identified: the lack of stability in the structure of our K'nex model causes minor wobbling and drooping. But a little sticky will fix things in a jiffy. This problem can be easily fixed with tape. Now, to mention about an improvement: we've increased the first gear's teeth's surface area by adding another gear beside the gear mated with the pole. Since this modification, all five gears are spinning beautifully. On a side note: it turns out that the crankshaft, which we switched to using instead of cams, cooperates with the rest of our design! Next up, we'll be finishing off the cardboard box that surrounds the mechanism. Decorations will be saved for week 12.

Looking industrial. :D

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Group Photo

Laurie:
"Their heads are so soft."
Joanne:
"Stroke stroke."

ALMOST THERE!

Week 11: Footage & Images

Those who haven't arms now, will soon.

Hang on, team!

Gear Prototyping

As I've been prototyping some versions of gears this past week, I've come across a problem. It's a fairly simple and solvable problem, but one we must address before the model build. As the gears currently turn, they mesh perfectly and each of them rotate about poles to stabilize their movement; as is, it works fine. However, two of the gears need to have the poles rotate with them, meaning that instead of fixing the poles to the box, they need to be attached to the gears. This will force us to create instead a platform to stabilize the gears. If we put holes in this platform for the poles, the poles can remain stabilized and rotate freely with the gears, thus solving the problem. It is also possible that we utilize either ball bearings or some other form of lubricant to allow the poles to spin with relative ease so as to not cause friction against the bottom of the box. This, of course, depends on how easy it already is to spin the poles, and this step may not be necessary if low friction is in place already.

Brendan

Week 10 Reflective Journal Response

As the group team enters into the 11th week, we have decided to distribute the roles as follows:

Brendan: SolidWorks assembly

Laurie: Assembling the box with precise measurements and aided Brendan with the SolidWorks assembly.

Emily: Gather wooden materials for crank shaft, and also assist Joanne in making the figures that will be attached to the platform.

Joanne: Designing and making the figures (adding the "spunk/attractiveness" to the project).

As Halil and John suggested, we have decided to make the box out of cardboard to avoid friction between the wooden crank shaft and holes in the box in which the wooden dowel mates with, to allow for smoother turns. Since the mechanical box is primarily made out of a cardboard, we may add corner supports to strengthen it. Currently, we've decided to try out k'nex to make the gears because they are neither too flimsy nor too tough.

The team has agreed to meet up on Monday afternoon from 11:30-3:30pm to begin creating the physical model as each team member has prepared over the weekend. We will begin recording our team work process on Monday so that we will have an adequate number of images and videos to save on a DVD by the thirteenth week.

Team:

Super Jumping Jelly Beans

Emily, Joanne, Brendan, Laurie.

Switching from Cams to a Crankshaft

Due to the proposed difficulty of making smoothly operating cams and followers, our group has opted to switch the cam structure at the back of the box to a more simple, single crankshaft mechanism to raise and lower a single fire element. After researching the matter, we found that cams can be very difficult to build and operate due to the fact that they will jam the mechanism if not smooth enough or calibrated correctly. On the other hand, we feel that a crankshaft will be simpler to create and will not pose as many difficulties during operation.

EDIT: It seems like the GIF I posted does not animate, so this is what it should look like (go to the bottom of the page:

http://www.animatedengines.com/howto.shtml

Sketches

yaY! figured it out xP

here are the photos we scanned of the sketches =)

Hello

testingtesting

Journal Entry - Week 9

In this week's lab and throughout the rest of the week, our group modeled our AMT parts in SolidWorks. In some cases, the transfer from sketch to modeled part was very simple; we modeled the cams, followers and shaft exactly as drawn, for example. In other cases, the models were simplified from the sketch. This happened in the figure, where our models of the humans and superheroes, fire and the building were simplified from our sketch. In other cases, parts were modified and fleshed out in more detail. For example, in our sketches, our gears did not possess teeth; we omitted that detail so that the drawings wouldn't appear cluttered or unnecessarily complex. However, when we modeled the parts, we required more accurate representations of the gears, and modelling the teeth was necessary for building and assembly purposes. In that sense, we must update our sketches to be more accurate concerning the final product, especially in the gears.

The parts that were most affected by the modelling process were the gears and figures. We believe that it is not too important to have exact replicas of the figures modeled in SolidWorks; as long as their overall dimensions are accurate, the details are relatively unimportant to the functionality of the AMT. Therefore, the most important changes we can make to our sketches are to update the gear drawings:

Journal Entry - Week 8

This week, our team worked on detailing, dimensioning, and refining our sketches from last week’s lab. As we dug deeper and explored the mechanics powering the automaton, we realized just how much work would go into developing and dimensioning the figure. Figuring out how to fit the parts we had decided on into the limited space, deciding what materials we would use to construct the toy, determining how to best avoid collision and interference inside the mechanical box, and simply drawing out the plans for the automaton were a few of the stressful issues we faced this week. As we move into SolidWorks and eventually into the making of the actual model, we still need to refine our sketches and make sure that the hypothetical model can be actualized in real life. One thing that would help us improve our ideas would be quick-and-easy prototypes for trial-and-error purposes, to make sure that we are not ignoring glaring problems in the design. Overall, we worked well as a team, and any conflict was smoothed over rather quickly. Most stress came from the difficulty of the project, not from internal animosity, which means that we are a cohesive, functional group that understands the needs and requirements for successful completion of the project.

Brendan Lane, Emily Tso, Joanne Goh, Laurie Low