Iridium Flare Tracker

iridium flare tracker

Iridium is a constellation of 66 communication satellites. Each one features 3 large polished antennas. The reflection of sunlight off of these panels causes brilliant flashes of light. Since the satellite’s orbit is known the time and location of these flares can be calculated ahead of time. C.L.I.V.E. is a project designed for Burning Man to assist in observing these flares. It has a DPSS laser mounted to a turntable that automatically points at the location of the next flare. A large clock counts down the time till the event. Everything is controlled by an Xport 2.0 FPGA development board for the Game Boy Advance. All power is provided by a solar array and wind turbines.

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Barcode Scanner Based Line Follower

line follower

Brody thought it was high time we featured another robot project and directed us to his site: bfrdesign.com. For his line follower bot he used an old barcode scanner he found cheap at a junk shop. The scanner has a 2088 pixel ccd linear image sensor. Several red LEDs are used to illuminate the image and the data is fed to an ATmega8. The wheels are then driven using two Sanwa servos modified for continuous rotation. He’s got a couple other projects on the site and I’m sure we’ll see more in the future.

Touch Probe For 3D Scanning

touch probe

Graham calls this touch probe his first useful milling project. He had already built the CNC mill and once he built this probe on the mill he essentially had a 3D scanner. The central hub is supported by three shafts spaced evenly around its axis. These shafts each rest on a pair of ball bearings to make a complete circuit. If the probe bumps into anything, one of the shafts will lift, breaking the circuit. TurboCNC has a built in routine for scanning with a touch probe. The program generates a point file which Graham pulled into Rhino for modeling. His example application was cloning a model airplane prop that had gone out of production. The TurboCNC routine isn’t very quick since the probe always returns to the same height so he’s coding a faster algorithm. This type of touch based scanning was also employed in agiecco’s LEGO 3D scanner.

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Phase Change Cooling System

phase cooling

Chris Morrell has an impressive write up on all the ins and outs of building a phase change cooling system. Vapor refrigeration moves heat from one area to another by changing the phase of the working fluid. Chris used propane as the working fluid in his system. He’s got instructions covering all of the work involved from brazing the copper tubes, to building and lapping the evaporator blocks, to the final tuning. With no load it’s can hit -45DegC.

This story reminded me to check back on extremecorvette’s cascading cooler from last fall. He started receiving parts last month for a brand new design. I can’t wait to see how that turns out.

[via Paul Stamatiou]

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