Team Van Gogh Uses OpenXC To Create Art From Your Drive

September 18, 2013 by Adam Fabio 11 Comments

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In this video, [Joe Grand] takes us through [Team Van Gogh’s] entry in the OpenXC hackathon event. In what could possibly be the greatest road trip in history, [Joe Grand, Ben Krasnow, TechNinja, and Super Awesome Sylvia] all pile into a car. With them they bring a host of dev boards, wires, a CB Radio, and of course Sylvia’s WaterColorBot.

As their name implies, [Team Van Gogh] took a more artistic approach to the challenge than other teams. OpenXC steering, gear shift, accelerator and brake data is sent through a ChipKit to an RS-232 link into [TechNinja’s] laptop. The laptop translates the data into commands for the WaterColorBot. With this system, a simple Sunday drive can become abstract art.

The team also showed the concept of what could be done if OpenXC was extended to send data back to the vehicle – something Ford doesn’t support. Their example works when a phone call comes in by using the system to lower the volume on a CB radio standing in for car’s Bluetooth system.

Most of this challenge was completed with simulated data from the OpenXC vehicle interface. The team only had a few minutes to work the bugs out in a real vehicle. However, they proved their concepts well enough to win the grand prize.

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Polishing Optics Milled From Acrylic

July 23, 2013 by Mike Szczys 11 Comments

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[Ben Krasnow] milled some lenses out of cast acrylic and needed a way to get an optical finish on the tool-marked surface. He tested several acrylic finishing methods to achieve a crystal clear finish. The tests were done using flat chunks. A regiment of sandpaper, from coarse to fine, was used as the first stage of the operation. From there [Ben] sought out the best finishing step, starting with hand polishing tests, flame polishing, and methylene chloride vapor polishing (which is something along the lines of acetone vapor polishing for 3D printed ABS parts).

Flame polishing and vapor polishing are not really exact sciences… at least in the tests he performed. It was difficult to know exactly how long to expose the acrylic. Too short or too long resulted in poor clarity. Watch his video to get a look at all results. We’d say the the easiest way to make milled acrylic clear without achieving an optical finish is to flame polish it as it doesn’t really require that you sand it ahead of time. But [Ben’s] tests prove that you can’t beat hand polishing with 600 then 2000 grit sandpaper before finishing up with a liquid plastic polish.

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Hybrid Rocket Engine Uses Acrylic As Fuel

September 26, 2012 by Mike Szczys 33 Comments

We are fascinated by the hybrid rocket engine which [Ben Krasnow] built and tested in his shop. It is actually using a hollow cylinder of acrylic as the fuel, with gaseous oxygen as an oxidizer. We’re already quite familiar with solid rocket propellant, but this hybrid approach is much different.

When a rocket motor using solid propellant is lit it continues to burn until all of the fuel is consumed. That is not the case with this design. The acrylic is actually burning, but if the flow of oxygen is cut off it will go out and can be ignited later. This also opens up the possibility of adjusting thrust by regulating the pressure of the oxygen feed.

[Ben] milled the test rig in his shop. It’s a fat acrylic rod through which he bored a hole. There are two aluminum plates which complete either end of the chamber. The intake has a fitting for a valve which connects to the oxygen tank. There is a nozzle on the outflow end. Check out the video after the break to see a full description. You’ll also get a look at the toll the combustion heat takes on the rig.

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