Lately I've been elbows-deep in some broken Playstation 3's and found myself wanting to test their cooling fans. These have a three-wire header with leads colored brown, black, and gray; you may be tempted to conclude that this is a brushed DC fan with a tachometer lead, but you'd be wrong. These are brushless fans, and the third wire is a PWM signal that you supply to control the speed of the fan. The two PS3s (both “fat” style) I've opened recently have compatible fans from separate manufacturers; one is a Nidec G14T12BS2AF-56J14 and the other is a Delta Electronics KFB-1412H.

Nidec and Delta models

It's not trivially easy to find datasheets for these fans, but no matter. If you just want to test them or need a good centrifugal blower for one of your own projects, do the following:

• Apply 12 volts across the brown and black leads; +12 V on brown with return on black. The fan will probably jump a little but it won't start spinning.
• Drive the gray lead with a TTL-level pulse train at 25 kHz from a signal generator or 555 timer circuit or microcontroller or whatever.
• Control the duty cycle of this pulse train to adjust the speed.

That's it!

I withdraw my endorsement of Audio-Technica's ATH-ANC1 headphones.

Fatigue failure of first one, then the other earphone support

Barely a year after I bought and first wrote about them, one earphone broke free from the headband; when I temporarily fixed this with electrical tape I was rewarded with about two weeks of additional service before the other earphone failed in exactly the same way. More galling than Audio-Technica's lack of attention to fatigue design, however, was their lack of attention to customer service—representatives of the company refused to make any replacement parts available and, since I was just outside of the warranty period, insisted I send them my headphones and pay more than half the price of a new unit to have them repaired. Nonsense!

Instead of dealing with Audio-Technica anymore, I took this as an opportunity to try out a technique I read about in Make magazine: fixing delicate plastic parts, such as the broken bridge of an eyeglass frame, by wrapping the joint with thread and coating it in epoxy, making a kind of thread-reinforced composite.

I needed labels for a small prototype run of a new product recently; lacking time to have these professionally made I bought some Avery-brand mailing labels and printed them myself on our color laser printer, finding that with careful design and a decent printer this type of label can produce surprisingly good results.

These 5195-type labels are 0.66 by 1.75 inch; 60 pieces come on an American letter-size sheet of backing paper. Avery provides templates for their label products in Microsoft Word format, which of course isn't good enough. I built a template in Adobe Illustrator instead and laid my design out on that grid. Because there's a small chance someone else in the world will find this useful, I'm writing this blog post and providing the AI template for download here.

• Avery 5195 Label Template, Adobe Illustrator

I spent a few days last week at a friend's house on Hutchinson Island, where I indulged my artistic side by stacking stones and shells on beach rocks after the manner (at least in my own small way) of Andy Goldsworthy. Hopefully somebody enjoyed it before the tide came in!

Lacking an insert plate for the 10-inch Delta bandsaw (model 28-195) at work, I made a new one out of ABS plastic using our 3D printer. Here's the result:

Rough-but-ready output from the Solidoodle

The geometry is two discs stacked on top of each other with a little bit of a cutout at the edge behind the blade, which helps prevent the insert from twisting too much. I've modeled a slot a bit larger than the kerf of the blade and included it in the printed part but you could certainly leave that off and cut the slot into the insert using the bandsaw itself, making what's called a “zero-clearance” insert.