Chrome + WordPress = Fail
I spent almost 2 hour composing a post on how to replace the CF pin module on Canon digital Rebels, but the post disappeared when I saved it. So here’s a picture of my work bench instead. I’ll probably stop being mad at wordpress next week, and will be able to finish the post then.
Canon EF 20-35mm f/3.5-4.5 USM Autofocus Repair
The Canon EF 20-35mm is a highly rated wide-angle lens that suffers from a common AF malfunction. Many users find the focus control stops working in both auto and manual mode. An excellent article by Piers Hendrie illustrates very clearly how to take apart the lens, and one possible fix for the issue.
The cause of this problem is that the USM ring motor (#4 below) is not applying enough pressure to the focus ring (5). Pressure is applied to the focus ring via a spacer (1), wave washer (2), and a felt ring(3). When you have this issue you can still hear the USM motor moving, but the focus ring does not move.
Photo credit: Piers Hendrie
Bike Light Parts Arrive
All the parts for my mega P7 bike light have arrived. The driver from Kai Domain came relatively quickly, but the P7 LED emitter from Deal Extreme took forever to arrive. Of course the driver came without any sort of labels or instructions so I’m going to have to search the candlepower forums to figure out how to hook it up. Now that I have all the parts I am going to draw them in solidworks and start designing the housing around them. The reflector ended up being much larger than I had thought so I may not use it.
Cleaning A MacBook Top Case
The top case on the first generation MacBooks are dirt magnets. While the palm rests on the black models simply become polished with use, the white models gain a disgusting brown patina. Apple’s usual suggestion of a damp cloth does little to nothing to remove the tan stains on the palm rest. Dirt and sweat from your wrists seeps into the tiny pores on the plastic surface, rendering in nearly impossible to remove with traditional cleaning methods.
They key to cleaning the top case is melamine foam. Melamine foam is formed when melamine resin cures under certain conditions. Melamine foam looks like standard open cell foam and is comprised of tiny, extremely hard fibers. These characteristics allows it to scrape away material from extremely small cavities, which is exactly what is needed to clean the top case.
Melamine foam is marketed under the trade-name Basotect from BASF. Fortunately it is also available to the consumer in the form of the Mr. Clean Magic Eraser from Procter & Gamble.
Lost Foam Casting
Most twelve-year-old’s idea of a crazy project is building a Lego car or a tree house. Mine was to build a backyard foundry. I’m not sure where I got the idea from, but I think it was seeing an advertisement for Dave Gingery’s series of books in the back of Popular Mechanics. Dave Gingery created a whole series of instructional booklets and plans for the home machinist. He had books on how to build just about any piece of equipment from lathes to band saws to foundries.
Fortunately I had a father who, when presented with the idea of his twelve-year-old heating aluminum to a liquid state, not only encouraged me, but helped me gather all the necessary equipment. He also kept an eye on me, ensuring I didn’t end up in the ER’s burn unit or on an episode of “World’s Most Bizarre Backyard Accidents.”
The Actual furnace was made from a large popcorn can lined with a sand/fire clay mix, and heated with charcoal. We used a blower motor from a discarded dishwasher to raise the furnace temperature high enough to melt aluminum. My dad came up with the clever idea of using a stainless steel camping mug as a crucible. The end result was pretty similar to what you see below.
DIY Tamron 11-18mm Lens Repair
As a general rule, I repair all my own out-of-warranty electronics. So when I bought, at a significant discount, a lens that had a broken plastic outer cover on it I performed the repair myself. This particular lens was made by Tamron, who happens to sell repair parts to the public.
Here’s the damaged part.
MicroRAX Micro Review
Most engineers and other people in industry have heard of t-slot (80/20, MayTec, Bosch Rexroth, etc) aluminum. It’s kind of like a grown up erector set, made of extruded aluminum and brackets. You can make just about anything out of it from industrial equipment enclosures to XY plotters to furniture. While is it well suited for these large applications it’s over sized for most smaller DIY type projects. This is where MicroRAX comes in. They supply a miniature version of t-slot measuring just 10mm x 10mm.
