Water Rockets

Intro

One day in the church parking lot, while waiting for an activity to begin, my step-brothers pulled out a bike pump and a soda bottle half filled with water. The lid of the soda bottle had a hole drilled inside with a bike tire stem poking out. They attached the pump to the bottle and pressurized the contents. Finally, one of them pointed the bottle up in the air and removed the cap. It rocketed out of his hands spewing water everywhere. That was my first introduction to water bottle rockets.

As kids we never took that principle any further. It wasn't until college when I learned that some people get very serious about building complex launchers and rockets. For me it has become a fun summer pastime, but not a serious hobby. I mostly enjoy launching rockets as a way to spend fun time with my children.

My Rockets

My first rocket no longer exists. I shot it so many times that the plastic got weak from landing and it exploded during pressurization. So unless you have a soft recovery system, I recommend retiring your pressure vessel after about 20 launches.

"Red Rocket", my second rocket, is a two-liter bottle with fins stolen from a firework. The nosecone is a Nerf football cut in half and hollowed to the correct weight. The fins and nosecone are attached by duct tape to allow fast repairs and relaunches. I've found duct tape to be very reliable and convenient in withstanding launch forces. These fins are too small to be really effective, so I'll probably replace them soon.

My family at the engineering competition, me holding "Red Rocket."

"One Night Wonder", my third rocket, was designed for an engineering competition at work. I procrastinated the build until the night before the competition. The nose cone was 3D printed, and I invented a circular fin that extends on launch. This system allowed the rocket to be fired from virtually any launcher design. With only a single good launch my rocket won second place for height, and first place for closest to target. The fin extension system used short sections of drinking-straw as linear bearings. The straws were cheap and thin and failed on the second launch. The design is sound and one I will duplicate with stronger materials.

"One Night Wonder" Maiden Flight

"One Night Wonder" Catastrophic Second Flight

My Launcher

I'll add a picture soon. You can find instructions on how to build a similar launcher from The King of Random. Or you can buy a kit from the Taylors. My current release mechanism uses a Clark Cable-Tie Launcher.

Useful Links

• Dean's Benchtop - Dr. Wheeler was one of my professors and bosses in college. He is the one who re-introduced me to the world of water rockets.
• Air Command Water Rockets - Lots of resources and tutorials.
• Clifford Heath's Simulator - I don't know Clifford, but he wrote a nice simulator for modeling different rocket design parameters. I've found it to be reliable for making design choices. It also allows you to change launcher and nozzle parameters.
• It's a Blast! - The Taylors were our neighbors while I was in college. They introduced me to the world of paper rockets. The pneumatic system I use for launching my water rockets is based on their launcher design.
• 3D Printable Rocket Parts - Here are some water rocket parts that you can print with a 3D printer. I used a nosecone in the engineering challenge.

3D Scatterplot Online, XYZ Plot in Javascript

Background

I'm an engineer by trade and by education. In my role I spend large amounts of time summarizing and presenting data to other people, usually engineers. Data comes in a variety of forms, and each form has a different way to be displayed. Information Visualization is an entire field of study on it's own. There are many software packages that have the ability to create charts and graphs. Some of them, like Microsoft Excel, are heavily used in almost every company. Other, more specialized, packages are often bought by a company to provide additional functionality.

One frequent type of data I use is called "xyz" data. I often just want to quickly chart a bunch of points in 3D space. Oddly enough, most standard software does a poor job of graphing "xyz" data. The default format for "xyz" data is a long list of rows where each row represents a point, and each point has three entries; one for each of x, y and z values. Excel won't chart this data unless you "pivot" the data into a different format. Other packages will chart the data from that format, but the chart controls to rotate, resize, zoom in and out, etc are kludgy at best.

The Idea

Since I need the xyz scatter plot so often, and sometimes in unusual places, it would be great to have an online interface to quickly paste some data and present a simple chart that can be rotated and scaled in real-time. Is that really too much to ask?! My Google-Fu is pretty good and I can't find anything online. How has no one done this yet? I've found contingency table calculators online that require a Chi table lookup. Most people in my industry don't even know what that IS despite it's usefulness. I don't want a free download, or an R script or an excel hack. I need to copy and paste my data and look at a plot in under a minute.

So I have to do it myself. Writing something server-side would be the fastest. I really like ColdFusion for this exact purpose, but that's not very common and I'd have to pay for some hosting. Maybe I will someday. My next natural inclination is to use JavaScript since it is client-side and available EVERYWHERE. But JavaScript doesn't have native graphics without using some kind of extension or additional package. Well, that was true until HTML 5, now we can use the canvas element to draw and display graphics natively in the browser.

Progress

01/27/2015 - First I created a static canvas of 2D points. Then I added the ability to import 2D points from a textarea html element. I added functions to project 3D points onto a 2D viewing plane then added buttons to modify the viewing angles. That took me a few hours. Next time I will add automatic scaling and chart annotations to give the chart some perspective. In the future I might add the ability for axis title and data labels, but that is a ways off.

02/10/2015 - Added automatic scaling and centering of chart, and the ability to make manual changes. Added corner points and XYZ reference lines. Once again it took me a few hours. Next I will add back-planes, gridlines and axis value labels.

02/21/2015 - Shading and grids are done. Shading helps a little, but perspective is needed to make the orientation clear. Also, drag to rotate would be helpful. I didn't want this to be a full-blown 3D project, so I'll probably stop here. I have what I needed; quick and simple 3D scatter plot.

Your browser does not support the HTML5 canvas tag.

Rotation Settings

Rotate By:				deg
X Rotation:				deg
Y Rotation:				deg
Z Rotation:				deg

Axis Settings

	Min	Max	# Intervals
X Axis
Y Axis
Z Axis

View Settings

Marker Size:				px
Zoom:				%

Paste xyz data below, separated by tabs, commas or spaces, then click "Import".