Salvage and signal, Oct 10
Dead machines coaxed back to work, and the sky and the airwaves read by low-power hands.
Tonight's issue runs on two ideas: salvage and signal. The salvage is literal. Dead machines coaxed back into usefulness. The signal is radio, and the sky, read by people working with little power and a lot of patience.
A maker known as bluesyann built a working belt file out of an old kitchen mixer and junk-bin parts, Hackaday's Donald Papp reported on October 9. The mixer's motor stays inside its original housing, which becomes the tool's handle. A 3D-printed pulley on the motor shaft drives a sanding belt that runs to a bearing fitted into a length of aluminum U-channel. A second piece of channel nests inside the first, and a threaded rod sets the belt tension. As Papp put it, "the enclosure for the old mixer is preserved and acts as a handle, so there's no need to worry about motor mounting and wiring separately." The parts list and pulley model are on Instructables.
The same day, Hackaday's Maya Posch described a bricked Prusa i3 whose hot end had blown out, rebuilt by a maker named Riley into an embedded 3D printer. An open-source Allstruder syringe pump on a Duet 3 board, extruding material into a supportive gel rather than laying down filament. Cream cheese made an ideal test. Epoxy in hair gel did not work, and a trifold torus printed in Sylgard 184 silicone held its shape but, Riley found, "the silicone print was still goopy after a few days," as additives in the gel kept it from curing.
For the salvager's parts bin, Al Williams profiled the TP223 capacitive touch sensor, which can replace a mechanical switch and senses touch through plastic, glass or wood, so it can sit behind a panel. Two solder jumpers, unsoldered by default, set four behaviors, and the chip draws under two microamps at rest. A reader cautioned that it calibrates its reference on power-up and can drift with temperature and voltage.
The signal half came from QRPer. Thomas Witherspoon, K4SWL, wrote that Solar Cycle 25 peaked in 2024, per NASA and NOAA, and is now declining. The higher HF bands of 10, 12, 15 and 17 meters get unreliable, so he steers operators toward 40, 30, 60 and 80 meters. "You won't be able to count on them the same way you can during the solar peak," he wrote of the high bands. Mark, KB2PIZ, learned the terrain the hard way across three Pacific Northwest parks, earning zero credited activations. A clean 1.2:1 SWR bought him nothing when cliffs sat between him and his listeners, since "high rock cliffs do not pass radio waves." Witherspoon also field-tested a roughly $100 Chelegance keyer, making 14 contacts from a hilltop.
Overhead, EarthSky's editors say Mercury reaches greatest eastern elongation at 10 UTC on October 12, 25 degrees from the sun and shining at magnitude -0.1 low in the west after sunset, the best evening showing of the year for the Southern Hemisphere, with the crescent moon alongside. Because it is the innermost planet, it "never ventures very far above the horizon after sunset," so timing matters. For binoculars, Astronomy Magazine's Alison Klesman points to M30 in Capricornus at magnitude 7.2, and to M52 near a Cassiopeia that looks like a 3 on its side. Mars crosses the Beehive cluster this week.
Closing the issue, Cool Tools recommends Anna Botsford Comstock's "Ways of the Six-Footed," essays on how bees, ants and caterpillars solve the problem of staying alive. Fitting company for a night about making things work with what is at hand.
Sources
- Belt File from Old Mixer and Junk Bin Parts · Hackaday
- Embedded 3D Printing with Liquids on a Bricked Prusa FDM Printer · Hackaday
- Getting to Know the TP223 Capacitive Touch Sensor · Hackaday
- The Solar Cycle Is Changing. Don’t Panic. · QRPer (Thomas Witherspoon, K4SWL)
- KB2PIZ: Three Parks, One Activation, and a Lot of Lessons Learned · QRPer (Thomas Witherspoon, K4SWL)
- Testing the New Chelegance JKEYER-CPO16 on a POTA Activation · QRPer (Thomas Witherspoon, K4SWL)
- Mercury is farthest from the sunset on October 12 · EarthSky, Tonight
- The Sky This Week from October 9 to 16: Mars passes through the Beehive · Astronomy Magazine
- The Sky Today on Friday, October 9: Dense, ancient M30 · Astronomy Magazine
- Book Freak #221: Ways of the Six-Footed · Cool Tools (Kevin Kelly)