Networks: Begin building

We got all the materials and began fully building today. We decided to put making the engines a priority today because Tim and I can't finalise the rails unless we know what the stirling engine design is, to make the connections work properly from engine to rail.

We managed to source our final materials as well. As mentioned in my previous post we found a design that we could make more easily, however, Ben still wanted to make the one we originally planned on making. So Edrian will take care of making the simpler one tonight while we start on the original one today.


We read through the instructions many times to make sure that we understood what we were supposed to do.


Once the cans were cut I filed down the sharp edges so that it won't be so easy to cut yourself on them.


Here Ben's seeing if the template we corrected is right for the can.


Edrian and Tim helped to saw some chocolate blocks in half.

Personally, I think it would be more efficient to go straight into building the simpler one because it would save a lot of time and would have less trouble. But when you're in a group you need to know when to object and when to let people go ahead and do their own thing.

The instructions for the original were confusing, but I heard from Ben and Edrian that in the end they broke the firebox they were making by accident. So they'll try again tomorrow to get things right.

When Tim and I left we started getting the ping pong balls ready by putting small holes in them so that we could fill them with water to control the weights. Also got a syringe from Daiso across the road to fill them. So I did that, and filled them with different amounts of water.




1. Completely empty
2. 10mL
3. 20mL
4. Full up 30mL

Next step for Tim and I would be to see if these weights would be fine and to see how much the counterweights need to be in order for the flip flop switches we're making to be effective.

We've decided that we can't use the dish vortex to slow down the flow of ping pong balls going to the switches. This is because the hole would need to be big for a ping pong ball to go through and therefore the dish would be proportionately huge. Thus, we can't use it because it would be way too big. An alternative we could try out would be the zig-zags I posted about earlier.

Networks: Change of plans

Yet again, the day was rather uneventful, so there's not much to write about. We did, however, change the kind of stirling engine we're building though.

I got most of the materials we needed to build a stirling engine over the weekend. When we went through instructions though, we realised it would be more difficult and unnecessarily annoying than we thought. So we found a better, simpler design that we could use instead by the same person.

I still think we're going to run into various problems though, but as long as we keep the pace up I think we can do this in time at an acceptable standard if not better. I feel a little bit unmotivated, but I think that would be because it feels like we're not doing anything and we don't have a solid object yet. I have a feeling it would be much like the movie we did last term; none of us would feel productive until we have something done that's solid.

We've got nearly all our materials, we can source them all by tonight and have them ready. Tomorrow, I think it would be beneficial to read through the instructions to have a very clear idea of exactly what we're doing and how to do it. Highlighting would be good. We need to name all our restrictions so that we have them in our mind to adjust the designs if needed. Then one Wednesday we can get straight into making things. We'll also prepare our materials for assembly tomorrow as well.

Networks: Mini-presentations

Today we had our mini-presentations and critiques on what exactly we're doing for this term. Our tutors today were James and Clinton.

First, we showed our film that we did for last term to put this term into context. The setting of the project is the solar flare and we talked about the basics of how we're going to go about building the system.

We got some pretty good feedback, which I'm pleased about. I was especially pleased about the feedback on how my group has clearly defined roles for each member and how this is a signature of how we work as a group.

The main advice we were given was to be careful about how our work translates across to the audience. This would be affected by our choice of materials and the design of our system.


Overall, the feedback was good, just need to think about what our system might mean to other people.

So tomorrow, it would full on designing. I want the basic designs down tomorrow so that we can get to experimenting as soon as possible, preferably begin experimenting on Friday.

For tonight, we'll go our separate ways, and think up ways to make a rotating wheel that can pick up the spherical packages and put it on the track. Also, what to use for the spherical packages.

Networks: Splitting of the Group

Talk about splitting the group in half. One for steam and another for rails. Explain why we're split this way and put in scans of your drawings.

We talked to Andy today about our project and where we're up to. It went pretty well I think. One thing I'm glad he brought our attention to is how complex our switching for the branching paths can be and how we need to differentiate between which packages go to which point so that we can still automate the routes even if one particular line is taken down. This is what a lot of the problem-solving will be about I think. Many calculations and adjustments.

We also decided that we should narrow down our network to serve a particular purpose. The setting of this project is post-solar flare, as mentioned before. So the primary purpose of this mailing system to send messages and maintain communication between areas. Therefore it's restricted to sending written messages only as opposed to objects and supplies, which I assume is best done in person so that you know what happens to it and where it goes.

This way we can also restrict our capsules to be a uniform shape. In this case, the best shape would be a sphere. It can move easily along tracks, which will be like pinball tracks, and it's the easiest shape to work with.

Our best bet is to trigger our flip flop mechanisms with specific weights. So we've got same shapes, but different weights to trigger out branching of tracks. This can be done by the flip flops I talked about before in my previous posts. For slowing down the flow of packages, we could use some sort of bowl with one hole at the base and zig-zags.



The bowl has curvature, so when a spherical package is shot near the rim it goes around and around the bowl. This slows down the package and only lets a certain number of packages go down at a time (Wandel, 2007). The best for us would be one at a time, so that there's enough time for the switches to reset properly.


(Matthiaswandel, 2007)


The zig-zags I'm talking about can be seen in this video, it's the structure with slopes and obviously look like a zig-zag:


(Matthiaswandel, 2010)

The zig-zags can also slow down the marbles. As the marbles fall through each hole, their momentum in going down the slope is interrupted. Therefore slowing it down a little bit, but down a slope it gains momentum again (Wandel, 2010). Thus, I can control the speed at which the packages roll down a zig-zag by using a slope at a low angle, and controlling at what height the package drops on to the slope. The drop is important, because it gives a brief interruption to the momentum, but also because if the height is too high, the package might roll off and bounce off the track.


Also, we've split the group in half for maximum efficiency and according to our strengths. We have the half that builds our stirling engines, and the other half that makes the switches and tracks. Ben and Edrian are better at making things, so they're grouped to make the stirling engines. I'm better at doing calculations and Tim has a good understanding of physics, so we're in charge of making the tracks and switches. To make sure that each half knows what the other half is doing and whether anything one half does affects the other, I'll be checking on both groups to make sure both sides are up to date on what the other half is doing. This also makes communication easier, and more control over how the group works as a whole. For example, if Ben and Edrian change an aspect of the stirling engine design that the tracks group doesn't know about, they might need to end up redoing all the tracks and calculations to make up for the change. This is why communications between two halves and having a person to oversee what both groups are doing is important. It's so that there's less of a chance of messing up because of insufficient knowledge about what the other half is doing.



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Reference List


Matthiaswandel. (2007, April 25). Marble machine 2 [Video file]. Retrieved May 1, 2012, from http://www.youtube.com/watch?v=9Z2A6qJyURY&feature=player_embedded

Matthiaswandel. (2010, October 10). Marble machine 1 (more detial) [Video file]. Retrieved May 1, 2012, from http://www.youtube.com/watch?v=SHPC7GVg1Zk&feature=player_embedded

Wandel, M. (2007). Building Marble Machine 2. Retrieved May 1, 2012, from http://www.sentex.net/~mwandel/marbles/machine2.html

Wandel, M. (2010). Marble Machine One. Retrieved May 1, 2012, from http://www.sentex.net/~mwandel/marbles/machine1.html

Networks: Paths and switches

Today Ben is in class, back from his trip to the UK. So now that we have our director back we can run through our idea and make sure that he's ok with it too. He's supportive of our stirling engine idea, so that's good.

We drew up a basic diagram of our network. We'll be doing it with four points to show how it works.



Basically, at each point you have one stirling engine. Which brings up the packages in its containers. As it rotates, the package is dropped on to a track which branches out into three tracks going to the three other points.

At each point you have three tracks sending packages out, and an additional three tracks receiving packages from the three other points.

To get two different directions at one point there are two options to do this:




One is to attach two additional gears on the other side of the main gear so that the directions can be opposite to each other. Option two is to simply stack an additional stirling on top of the first one, but facing a different direction.

Personally I think there's a better way to do that, but will be thinking a bit more with the group tomorrow. At the moment the visualisation of outgoing and ingoing packages as lines is a bit fuzzy and spaghetti like. So tomorrow we'll be marking out these lines and points with chopsticks and string to see where our tracks are all gonna go. It would also make it clearer for us too.

About the branching out of tracks, there's a way to do it.



The idea that we have for it at the moment is that we have these cylindrical capsules that have a notch on the left, right, or no notch at all. The notches will activate a pivot switch, redirecting the capsule's track to a different one that leads to its destination. The one without a switch remains on the original track towards its destination.

It's still just an idea though, because we're not entirely sure the specifics of how we're going to get these pivots to work yet.


Here are the things we need to keep in mind:

-The pivots/switches have to be sensitive to work properly

-Need to work out how to integrate the switches on the track

-Must have something before the branching of tracks to slow down the flow of packages. This is to avoid jamming the path with too many packages.

-Track has to be designed to keep capsules in place so that the triggers for the switches would work

-Capsules must have sufficient weight to gain enough momentum, since the tracks will be sloping, letting gravity help the capsules move.


After talking with the group we went separate ways to find more information on how we could do this.

For me, I think our tracks should all be straight slopes going down to the destination. It's the switches that I want to find out more about to get the branching out to work properly.

Yesterday I blogged about this marble machine video I found. In it, they've got this weight-sensitive flip flop mechanism that I think would go well with our switching. I have a fair idea on how it works already, so I went to find something that would slow down the flow of packages.

This is what I found (Denha, 2010):



I thought this was pretty cool. I like how it directs the marbles on to different paths and then stores the marbles until there's another to set them all down to a different route. I'm not sure how much it can slow down the flow of marbles, but it's definitely interesting. I might be worth testing out, especially because it's not that difficult to make.



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Reference List


Denha. (2010, December 22). RS-FF + AND logic [Video file]. Retrieved April 30, 2012, from http://www.youtube.com/watch?v=Huspz20MTDE&feature=related

Networks: Ways to move

Found some things that we could take inspiration from in getting the packages to move with the stirling. It could work kind of like a water wheel. Instead of the fly wheel being a gear, you could attach containers on it like on a water wheel where you could put your packages. As it rotates, the packages move up the wheel and are dropped on to some kind of chute. Gravity will do the rest of the work in moving it.

From videos of marble machines there were some things I think that we could maybe use. In the video below particular features I want to experiment with are the levers, which control how many marbles can drop down on to a different chute at any one time, and the flower pot vortex.


(RonaldWalters47, 2010)


The lever is sensitive to weight, it has a counterweight on one end to reset it, and on the other end it gathers marbles until the right number of marbles giving the required weight tips it over setting the marbles free to go down a different chute. This would be a good way to stagger the number of packages going down a particular chute at any one time to prevent jams in a particular direction.

The vortex funnel is amazing in my opinion. I don't know if we could use it, but it definitely slows down the marbles, giving them time to get to where they need to go so that they don't crowd up a path way.



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Reference List


RonaldWalters47. (2010, December 18). Marble Machine - Ring Gear Lift - Figure 8 Transfer - Vortex Funnel [Video file]. Retrieved April 26, 2012, http://www.youtube.com/watch?v=QzIG9stFXSI&feature=related

Networks: Stirling Engines and Gears

After looking further at steam engines I found a far better alternative. An option for the steam engine is the stirling engine, also mentioned in the previous post.

The good thing about it is that it works with just heated air as well. As long as you increase the difference in temperature as much as possible, it would work efficiently (ScrapToPower, 2010).
I found two really easy to make ones from the same guy. It was from these I found on Instructables that I found the stirlings could run on air just fine.

I chose these two to be considered by my group because the materials are easily found and easily affordable. Resourcefulness, I think, is a good trait to go for.

The first is a tin can stirling engine (Specallez, 2010, April 22):



The second is also a tin can stirling engine but with slightly different design (Specallez, 2010, July 21):



The difference is that the first one is easier to build than the second one, but because of the second one's improvements it works better than the first.

Had a look at gears with the group as well since we need a way to use the engines to move our packages. A way to do that would be to use gears and pull along something like a conveyor belt to transport a packages. However, I can see things wrong with that. First of all, we want each engine to branch out into multiple pathways. Because of that we'll need to split the conveyor into different branches, but there'll be no way to automate it. Secondly, if it's a conveyor the stirling has to produce enough energy to move the gears, the conveyor belt, and the weight of the packages. In terms of energy, it's not very efficient.

Nonetheless, we found some pretty interesting stuff.

We found out the basics of how gears work in a tutorial about differential gears (Antoniobmartinez, 2011):


It's really clear on explaining how gears work and why they're designed the way they are. It's quite interesting.

We found a collection of amazing gears of different shapes and sizes working in unison as well (Quilty1987, 2010):


I thought it was pretty amazing how they could all work together.

Another I found uses a different sort of gear, it uses a worm gear at the end of the contraption which you can see in the video where the handle turns (5thwelder, 2009):



Next step is to see if there's another way to move things with the stirlings without conveyor belts. I'm sure there's a way.



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Reference List


5thwelder. (2009, July 13). When 17 Things Line Up [Video file]. Retrieved April 26, 2012, http://www.youtube.com/watch?v=uLjI1t40pL4&feature=related

Quilty1987. (2010, July 1). These Gears Really Work? [Video file]. Retrieved April 26, 2012, from http://www.youtube.com/watch?v=WYcqJ5HdxA4

Antoniobmartinez. (2011, November 2). How Differential Gear works BEST Tutorial [Video file]. Retrieved April 26, 2012, from http://www.youtube.com/watch?v=rxHjKoB2vn4

ScrapToPower. (2010). Make a coke can Stirling engine plans. Retrieved April 26, 2012, from http://sites.google.com/site/reukpower/can-stirling/make-a-coke-can-stirling-engine

ScrapToPower. (2010). Easy to build Stirling engine fan. Retrieved April 26, 2012, from http://sites.google.com/site/reukpower/projects/easy-to-build-a-stirling-engine-fan

Specallez. (2010, April 22). Simple Coke Can Stirling engine [Video file]. Retrieved April 26, 2012, from http://www.youtube.com/watch?feature=player_embedded&v=PsvyO9chvS0

Specallez. (2010, July 21). Easy to build Stirling engine fan [Video file]. Retrieved April 26, 2012, from http://www.youtube.com/watch?feature=player_embedded&v=Heg3xaWUMks