Entries in Category Repairs and Restorations

A Cam Mechanism Hole Punch

I'm informed by google's doodle that today is the 131st anniversary of the invention of the hole punch. Here's a lovely example from my office:

Restoring a Steel Outdoor Table

Some years ago my mother found on the side of the road a small steel patio table, rusted, with original black paint in desperate condition. She brought it to my house, thinking that someday I might want to do something with it. Someday was last weekend.

A Stainless Steel and Cedar House Number Plaque

Here's something I made recently. For many years my house number was marked by stainless steel numbers from Blomus that have bosses on the back so that they float off of the wall surface somewhat. When we painted the house gray the stainless just didn't have enough contrast against that background, and since I had done a gray-plus-wood sort of theme in the recent bathroom renovations I decided to extend this to the exterior of the house with a sort of wood plaque behind the house numbers.

Driving a Playstation 3 Fan

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!

Repairing My Audio-Technica ATH-ANC1

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.