3… 2… 1… Blast off!

Space has often been referred to as the final frontier, and many who look towards the heavens find themselves wondering what might be hiding just beyond our reach. Although commercial space missions cost well into the millions and even billions of dollars, model rocket enthusiasts have been striving to reach just a bit closer to space for decades. Estes model rockets have allowed generations of kids to dream about one day escaping the earth’s gravity and venturing into the unknown. I like to think that a bit of exploratory spirit can be found in everyone, and I am certainly no exception.

We all know that when you have a hammer, everything starts to look like a nail, and the same is true of 3D printers. When we first acquired a 3D printer, our first thought was: “why don’t we print a rocket?” And here we are. Since anyone can buy off-the-shelf components and put a rocket into the air, we opted for a slightly more challenging approach by attempting to make every component of the rocket ourselves – including engines, igniters, and launch system. This post details our progress so far – after a handful of launch attempts we have successfully made every component except the engines (we’ve been using Estes model rocket engines until we can create a suitable replacement).

CAD Drawings

The rocket body consists of several modular pieces that were designed to be somewhat configurable and interchangeable. The tail piece has 4 identical fins that slide into place using a friction fit, and an engine stop that slides inside (which can be adjusted based on the type of engine). The body pieces then lock into place on top of the tail assembly. The number of body pieces used determines the height of the rocket, and guide rings for the launch pad can be fitted on to keep the rocket going straight. A flame shield (a replacement for the normal recovery wadding) slides down into the body to protect the parachute from the ejection charge. And finally the nose cone goes on top.

Rocket Body

Rocket Fin

Rocket Nose

CAD files for printing the rocket are available in the Profusion repo. All CAD work by Bryan Den Hollander.

Wireless Launch System

Wireless Remote Launch System

In keeping with the DIY theme we wanted to avoid buying an off-the-shelf launch system, so we started off using a 12V battery and some long wires, shorting the igniter across the battery to activate it. This quickly became cumbersome, mainly due to the limiting length of the lead wires, so we decided to build a wireless system. Some unused Xbees we had laying around became the obvious choice for a quick and easy wireless link, and the rest of the design choices were similarly dictated by parts on hand.

Remote

Launch System Remote Schematic

The remote is a handheld device powered by a single lithium primary cell (3.6V, 2400mAh) and contains nothing more than an Xbee, a few buttons and switches, and their corresponding LEDs. The power switch turns on the Xbee, and the arm switch communicates an armed status to the base and allows the fire button to be triggered. The arm and trigger inputs are sent to the base station using the Xbee’s built-in line passing, which essentially mirrors I/O state on two or more Xbee modules. To verify communication with the base when arming, the arm input is sent to the base and then relayed back to the remote. The circuit is detailed in the schematic above.

Base

Launch System Base Unit Schematic

The base station is powered by a much beefier 3S lithium battery pack (11.1V, 2600mAh), due to the large amount of power required to set off an igniter. It also has an Xbee, which receives line passing signals from the Xbee in the remote. When the trigger is activated, a p-channel mosfet is turned on to allow current to flow through the output (and to the igniter). Status LEDs indicate the state of the base unit. The circuit schematic above gives the full picture.

Igniters

DIY Igniters

A DIY launch system isn’t complete without homemade igniters, so we acquired some nichrome wire and pyrodex (black powder substitute) to make our own. By twisting a bit of nichrome between two copper leads, and then dipping the tip in superglue before coating with a pinch of pyrodex, electric igniters can be made by the dozens for just pennies.

Launch Video

Coming Soon!

Check back for updates as we continue to progress with this project. Plans for the future include DIY fuel, GPS tracking/telematics with a custom rocket controller, and thrust vectoring.

This is a build log of my PID modification to my DeLonghi EC155 espresso machine. Currently, the machine uses an Arduino to drive a solid-state relay controlling the heating coil. The Arduino displays mode and temperature on a serial lcd, and also dumps status information over the serial port.

Update 1: I’ve ordered parts for a permanent install on protoboard, after I finish the install, I’ll update this post with build instructions and details. I will also provide a link to a mouser project where you can order most of the parts in one place.

Update 3: Everything is assembled and functional, and I made an aluminum case thing for the LCD and rotary encoder. Photos to come soon. (8/25/10)

Update 4: ZonCoffee .2 is released! See the release page to download the sketch and to see additional hardware information. (1/4/11)

This post is one of a series of posts regarding mods I have done to my EC155

Required Parts:

• Thermocouple ($2, ebay)
• MAX6675 (maxim-ic) (now sold by sparkfun! 7/17/10)
• Arduino-bootloaded AVR  of some sort ($30, sparkfun)
• Solid-State Relay 25A+ ($7, ebay)
• Switch (any type will do)

Optional Parts:

• Serial LCD ($25, sparkfun)
• OSRAM SLR/SLG/SLO 2206 LED Display (driver coming to ZonCoffee soon, will require shift register)
• Screw Shield ($10, sparkfun)
• Rotary Encoder

My build is currently on a Arduino board with a screw shield, but I’m planning on making a PCB soon. I’ll update this page with links where you can purchase the PCB (probably through batchPCB) in the near future.

Software:

• Modified BBCC code (arduino sketch)
• Modified MAX6675 library
• BBCC plotter (processing sketch) [link]

Construction:

1. Installing the SSR and Thermocouple (coming soon)
2. Connecting the electronics (coming soon)
3. Editing and uploading the software (coming soon)
4. Calibrating the thermocouple (coming soon)

In this short guide, you can learn how to create an easy yet professional-looking fixed-width website with free open-source software. Before you begin, ensure that you have the Gimp and Inkscape installed, in addition to some form of text or code editor (any variety will do).

This guide provides a basic guideline on creating a site simply and easily using few tools. Feel free to try different techniques, see how it works, and leave some feedback in the comments. Feel free to comment on how to improve this article!

Initial Design

First, open up Inkscape and begin visualizing what you want your design to look like. If you have not used Inkscape before, check out this simple Inkscape tutorial.

Things to keep in mind:

• Your design should include a header, menu bar, mid-image portion, and footer portion
• The menu bar portion can have image-mapped links, or you can overlay text links on a background image
• The middle image portion should be vertically tileable for a fixed-width variable-height site.
• The footer can include image-based text, or text can be overlayed on a background image

After you visualize your initial design in Inkscape, you should have something similar to the image below. In this tutorial, we will be creating a site with a header, an image-mapped menubar, a tiled text background, and a footer image.

Your initial Inkscape design should look something like this

Exporting the Design

After you have created your design in Inkscape, you must export it to a raster format so it can be parsed by web browsers. The resulting raster image also needs to be separated into different portions that we will reference in our CSS. The fastest and easiest way to accomplish this is by creating a “chopper” layer above the layer(s) your design is in. Go to [Layer –> Add Layer (select “Above Current”)] and put in whatever name you wish.

In this layer, you will now begin creating squares to mask off various portions of your design. Start out by dragging a square across the header portion of your design. Zoom in and make sure that the edges of your mask are aligned with the edges of your design. After you create the first mask, copy the mask and paste it below. This time, center the block on your design and only adjust the height, not the width. Continue this process until you mask each portion of your site: header, menu bar, middle tile, and footer. I find it easiest to color-code these sections and make them semi-opaque, as shown below.

Your completed theme with different portions in different translucent colors should look something like this

Finished? Take a break and check out some of the notes below.

Notes:

• The footer in this design will have copyright info on the image itself, therefore search engines and visitors printing out your site will not have footer information. You can easily add a text-based footer to your design, but this won’t be covered in this tutorial (yet)
• Many other items, such as the menubar imagemap, can be substituted with a text-based menu with an image background behind it. This is usually a bit more flexible, and nicer to search engines.

Ready to move on? If you know some CSS, you can probably figure out this part yourself. You can create