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Book binding press This bookbinding press combines many functions into single, compact device. My aim was to make something that doesn't take too much space to store, but is sturdy and useful. Most DIY bookbinding press designs consist of two plywood sheets and four threaded rods. This is simple to make and likely works well, though I expect it is somewhat slow to use because of the four screws…
Repairing stripped internal gear After a decade of hard use, a plastic gear in my Black & Decker Gyro Driver screwdriver gave up. I really like the small form factor and precise control, but the model is no longer manufactured. Therefore I set out to repair the one I have. What is a gyro driver? Gyroscopic screwdrivers only have a single push button. Rotation direction and torque is controlled by…
BGA inspection using plastic prisms BGA (Ball Grid Array) packaging for microchips is getting more common as devices become smaller. It's quite feasible to solder with a basic home reflow setup, but verifying the results is difficult. The gold standard would be X-ray imaging, but short of that you can use optical verification with simple prism tools. Optical verification principle The idea is to…
Relay multiplexer for lab instruments I have been adding programmable equipment to my home lab: USB connected power supply, electronic load, multimeter, oscilloscope and function generator. This is great for doing parameter sweeps and long term tests. But often I have more than one thing I want to measure with the multimeter. In this project I build a simple relay multiplexer for selecting signal…
Improved frequency reference for ELV FC-500 As one of my first electronics projects, two decades ago I built a ELV FC-500 frequency counter out of a kit. It has worked great and found use in several projects where I have needed to check the accuracy of oscillators. I just wished for a bit more accuracy on the meter. Original design The FC-500 is based on a 24-bit ripple carry counter implemented…