Week 07 Behavior Tutorial

Week 06 Behavior Tutorial

Above and beyond

After formally joining my team with Kane Henderson and Patrick Ford, we decided to continue our design development of the bus tracker. To fit into the constraints of the new brief we decided to change the tracking network from a GPS system to live Tweets on Twitter. Each bus in the city will have its own twitter profile, and will send automatic tweets when leaving each station on route. The driver will also have the opportunity to manually tweet passengers in case of an emergency etc. The bus stop will have some sort of tangible interface where passengers choose the destination they wish to travel to and receive information about the next bus going to that stop.

This got us thinking about what people do at a bus stop. It’s boring, it’s frustrating, it’s a real pain when you don’t know where the bus that was supposed to arrive ten minutes ago is. So a tangible interface that gives passengers something to do while they’re waiting for their bus, like playing a game, has been the main focus point in the design process this week.


http://dornob.com/spill-espresso-in-style-clever-coffee-cup-saucer-maze-set/

I found this saucer that gives users something to do with their hands while enjoying a cup of coffee. Cool stuff.

I believe the scenario facet of this project will be a major contributor to this design, as users are in many different situations when they are using a bus stop. Kane is handling this side of the process, Patrick is focusing on the object and I am studying behavior. Although we have branched off into these sub-categories we will continue to meet up and work through the whole process as a group.

Into the future

As the design continues to develop I’m investigating the possibility of making a micro version of the positive displacement pump. I plan to make the housing of the pump circular as opposed to square so it can fit inside a bus stop pole if it were laying flat. The manufacturing process would be quite similar to the pump seen in the final concept presentation, with the exception of smaller bearings on the ends of the windmill arms and possibly some skinnier tubing. I believe the friction will be substantially less with the smaller sized pump plus we have identified high friction areas that would be addressed with the new design. So using the step motor will again be considered.

We would like to combine some of the elements each person presented in the concept presentation. A large scale sculpture/timetable/map where all the bus lines are represented by clear tubes and the buses by the water slowly draining down these tubes, is one idea that we have played with. I think before we proceed any further into the design process a clear context needs to be established, as there is a lot of difference between the bus stop at the Cultural Center and the stop two minutes from your front door.

Final concept

I went to the presentation with the positive displacement pump which I worked on collaboratively with two class members, and the container which the water would flow into from the pump. To represent the container being inside a bus stop pole I used a glass alcohol bottle wrapped with a piece of acrylic. I had the stops laser cut out of the flat piece, then heated it under elements and wrapped it around the bottle. Originally I wanted to use an opaque plastic, so the water would only show down the line I had cut down the piece, but due to time restrictions I could only get hold of a clear piece, which turned out fine to show design intent.

In terms of manufacturing, the base I constructed to house the bottle was poor construction which showed when it leaked everywhere during the presentation, this I could have done better. When I was heating up the acrylic sheet with the help of a workshop guy, and stared draping it around the bottle, it was a lot harder to get a clean mould than I thought. In retrospect a prefab acrylic tube may have been the better option.

Pump Working!

As you can see from the video Patrick and I finally got water to pass through the pump, aided by a power drill as the two motors we assigned to turn the pump failed. My trip to three hobby stores yesterday in search of sprockets to connect the step motor and drive shaft sprockets yielded zero results, so we couldn’t use the step motor. We foresaw this problem when we decided to use this specific drive shaft so we saved the 12v electric motor from the remote controlled car to use as a back up. But there was always the question of the smaller motor having enough torque to turn the pump. Turns out it didn’t, even with two 9v batteries and a variable resistor, the motor would simply cut out when we gave it surplus power.

For the final design we would like to use the step motor running via a program so we can accurately measure the water going through the pump. I was recommended a great online store from one of the guys from Hobbyrama http://www.smallparts.com/ where we should be able to find the sprockets we need to do the job.

So for the concept presentation we are going to use the power drill to turn the crank which will pump water via spaghetti tube, from a syringe, into a bottle wrapped in acrylic which shows where the bus stops would be.

The Pump: nearly pumping

Here are some shots of the latest model of the water pump. The gears were taken from a remote controlled car and we have left them in the chassis so we don’t need to make a new housing, that is if the gears are even used, which is dependant on my trip to a hobby store tomorrow. Basically the teeth on the sprocket fixed to the step motor are too thin to mate with the sprocket on the drive shaft. There are a number of options that are open to us which include: making our own gear system with laser cut or bought gears, a chain drive or if worse comes to worse cutting new windmills for the pump with an alternative female drive hole.

Step motor

Last week Patrick and I bought a step motor kit from J-Car, and have been working on it until last week when we got it to work. At the moment the motor is running off pre-programmed sequences via the circuit board we soldiered. Later in the design process we would like to program a suitable sequence with the included software, to make the design feasible.

Lasers

I got some windmill attachments for the displacement pump laser cut during the week. They turned out great!
As the second picture shows, two are going to be used with three skate bearings pinned between. This should give us even pressure and flow over the silicon tubing.

Collaborative design

Up until recently I have been working on the bus tracker design with two classmates Patrick Ford and Kane Henderson. For our individual initial concept presentations we are presenting the same mechanism that could be used in three separate scenarios. We have justified this collaboration on the complexity of the mechanism we are trying to create. Once we have finalised the mechanism we will then branch off and explain our individual concepts. As the bus tracker was initially my idea so I am keeping the concept.

Arcs and routers

The following picture describes the latest concept for the bus position monitor. It involves using a stream of water slowly filling up a cylinder to show the progression of a bus on route. The mechanism would work using a positive displacement pump driven by a programmable step motor to regulate exactly how much water passes into the tube. So we went and bought a step motor.




As of yet the step motor remains un-programmed due to software issues but construction of the positive displacement pump initiated in yesterdays workshop tutorial. The clear 12mm hose that Patrick brought to the tutorial was a good tool to visualise the pump and decide what materials would be best for this design. But we later realised (after consultations with tutors and workshop staff) that the hose was too thick and the arc we routed out for the pump to turn in was too large.




After this hurdle we decided to use a smaller diameter hose (about 3/4mm, made of silicon/similar) and route out a smaller and more accurate arch using the drilling press/router machine in the workshop. We finished the session with a much more accurate and feasible pump housing and a clearer idea on resolving this design.