A Volume Control From A VCR Drum

The VHS VCR has now passed from widespread use, and can thus be found as a ready supply of interesting parts for the curious hardware hacker. [Clewsy] has a novel use for a VCR head scanning drum, the part that is supposed to be tasked with reading information off of magnetic tape. Instead, it’s reading information from fingers as the knob for a USB volume control. Underneath the drum is an optical encoder disk which is read by an ATmega32U4 for USB interfacing with a host computer.

The helical-scan video recorder was a mechanically complex solution to the problem of recording a high-bandwidth video signal onto a tape that could be made slow-moving enough to be practical. By recording the video in diagonal stripes across the tape from a fast-moving spinning head they avoided the need for huge reels of tape, enabling hours of video to be fitted into a roughly book-size cassette.

While over time the mechanics of a VCR mechanism were simplified and cheapened to a great extent, the heads and drum were the one area that could not be compromised. Thus the VCR head was for a time the most high-precision mechanical device owned by most consumers, and the drums usually have exceptionally nice bearings. All of this makes one a particularly good choice for a volume knob or indeed any other large rotational control, so much so that we’re surprised it hasn’t become a more frequent occurrence. So scour the electronic junk, and you might just find the ultimate in free high quality control hardware.

Of course, this isn’t the only thing a VCR head drum can do.  How about a centrifuge?

Pan/Tilt Wheel Trainer Ends Up Being A Different Way To Play Quake

This is a special controller that [Gary Scott] built to help train camera operators. The pan and tilt controls on high-end movie cameras use wheels to pan and tilt smoothly. This rig can be built rather inexpensively and used to practice following a subject as you would with a camera. This is where the project takes a turn into familiar territory. [Gary] set up a system so that you can play the game Quake using this controller, with your feet doing the rest.

The pan/tilt controller uses two heads from an old VCR. They are mounted above the guts from an old ball-type mouse. A couple of rubber belts connect the heads to the two mouse bars that are normally rotated by the ball. This gives him control of where the Quake game is looking. But he still needed to be able to move, jump, change weapons. and shoot. So he built a second controller for his feet. It uses a CD and some switches as a joystick, and a set of buttons for the other controls. He actually rigged up solenoids to each of those foot switches to physically press keys on a keyboard. You really must see it for yourself. We’ve embedded his set of videos after the break.

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