Automatic Laser Level Made From Hard Drive Components?

hard drive laser level

[Crispndry] found he needed a laser level, but didn’t want to spend a few hundred dollars on a tool he might only get a few uses out of… So he decided to build one himself.

If you’re not familiar, a laser level projects a laser beam, level to wherever you put it — it works by having a very precise gimbal assembly that keeps the laser perpendicular to the force of gravity. To build his, [Crispndry] needed a highly precise bearing assembly in order to build his gimbal — what better to use one out of a hard drive?

He used the main bearing from the platter for one axis, and the bearing from the read and write arm for the second axis. A square tube of aluminum filled with MDF is then mounted to the bearings, creating a weighted pendulum. The laser pointer is then attached to this with an adjustment screw for calibration. 

Calibration is the tricky part. His new gimbal assembly is guaranteed to be perpendicular to gravity, but the laser pointer mount isn’t. Using a long tube filled with water he shone his laser pointer across his garden and adjusted it until it was parallel to his water-tube level. Clever!

We’ve actually seen a similar build a few years ago, with its own merits — though [Crispndry’s] is a bit more refined.

15 thoughts on “Automatic Laser Level Made From Hard Drive Components?

  1. Nice, but what about Flip-Flops, latches, memories, etc. Ternary logic is really nothing new, MLC flash drives essentially use a similar technology , using different logic levels to encode data.

    1. He actually used a water tube to calibrate his laser level. Not a bad idea if you can do the laser level cheap like this, as water tubes are also cumbersome and subject to errors if half the tube is in hot sunlight and half in cool shade, as can happen.

        1. Water changes density at diffrent temperaturs. For an extreem example if the vertical coloumn inside is at 1°C and the vertical coloumn outside is 40°C you would have a 0.77% error.

          1. On a 2m high column of water, that’s an error of 14mm. He’s using 20m between points. arcsin(14/20000) = 0.04 degrees. If he uses half-metre columns of water, even with that enormous temperature range, that goes down to 0.01 degrees. A quick look at a $250 line laser quotes 1mm accuracy at 5m, so he’s close on that with 1.6mm accuracy at his gate post height.

  2. Umm… Much respect for the creative hack, but really? The big benefit of a laser level is its pinpoint accuracy – some of them claim 1/16 inch accuracy at 50 feet plus. I guess if you were just needing a quick fix for a rough project, this is pretty awesome. If you’re doing cabinetry or something… drop the $100 on an accurate tool. Thanks for sharing!

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