Bruce Land let us know that the final projects for EE476 Microcontroller Design, a class he teaches at Cornell, are online now. You may remember some of last years projects: P-P-P-Palm, Big Red Juice Mixer, wireless telemetry. This year’s projects include a Reflow oven controller, an RFID security system, and an autonomous helicopter plus many, many, more.
As a follow-up to yesterday’s post, [owen] sent along a link to his computer controlled router table for balsa cutting. This was his project before switching to lasers and sheetmetal. The write up starts with an interesting discussion about CNC not really being a magical tool or time saver. Sure, it can be pretty quick about cutting accurate pieces, but you still have to assemble it. Most likely all of the time you saved cutting was spent designing and prepping, which you could have spent cutting accurate parts by hand. Owen had extra time to spend designing since he was traveling for business. He does admit that the ability to quickly generate replacement parts has made him a more courageous pilot.
Other gems from yesterday’s comments: CNCZone is apparently the one-stop shop for all of you CNC hobbyist needs. [javamoose] pointed out that he’s nearly done with his scratch built CNC machine seen on bit-tech. [mike]’s FIRST robotics team is in the process of converting a punch tape driven Bridgeport NC mill. They found the owner of wimb.net very helpful. [ivan256] recommended the plans found on John C Kleinbauer’s site.
Ben Hui had been planning on purchasing an RC helicopter, but with a little more reading he was determined to build his own (cache). Most of the bracketry is built out of the fiber board base used for PCBS. He has details of how he constructed the swashplate, rotor head, tail rotor, and how to make your own blades. He eventually modified a brushless CDROM motor to drive the main rotor.
[thanks Jan]
There was a little interest in Graham’s 3D scanning probe, but this is what he is normally using his tiny CNC machine for: manufacturing components for a tiny RC ornithopter. The scale of this thing is amazing. From the tiny gear train to the 0.5mm carbon spars the frame is constructed from. The rudder control only weighs one gram and the entire device comes in at 17 grams.
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.
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.
Khoa wanted to give a friend a microcontroller programmer(cache), but didn’t want to spend the money. He found almost every part he needed inside of a broken monitor he had in the closet. The only parts he had to provide were the perf board and the serial port. Even the socket was in the monitor. It was too wide, but he just cut out the center spar and made the socket narrower.
