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.

Comments

  1. Anne Nomymous says:

    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.

  2. fartface says:

    Water tubes have been in used for construction for thousands of years.

    • localroger says:

      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.

      • Mike Lu says:

        And it can be way off if there are bubbles in the tube.

      • lejupp says:

        > water tubes are also cumbersome and subject to errors if half
        > the tube is in hot sunlight and half in cool shade

        Uh, how is that?

        • bWare says:

          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.

          • lejupp says:

            So the water line on the side with the warm water would be further up than the side with the cold water?

          • RichC says:

            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.

          • Velli says:

            What are you leveling outside that stretches from the arctic to the tropics?

        • derpa says:

          The tube itself can warp with heat which will disturb the balance, especially with surveyor’s bubble levels as those are very delicate.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 96,755 other followers