The astrolabe is a multi-function calculator of the Real Old school. It can help you find the time, day or night, quite accurately. It can do basic surveying, determining distance, depth and height. This is a working model of a basic, fairly common set of options. I have included a zip file containing plates for 05-70N latitude.

Tools

• Laser cutter
• 3D printer
• laser printer

Materials

• 1/8 inch sheet clear cast acrylic
• 1/8 inch sheet opaque cast acrylic (I have had good luck with Blue and Black)

Hardware

• #6-32 screws and locknuts, 1 1-inch, 2 3/4-inch

Files

• front_symbols, front_roman: two variations for the front.

• blank: The blank center section
• back: The back plate
• rete: The rotating section
• Alidade, Rule: Parts to be 3d printed

The laser files are colored as follows:
RED: Cut through the material
BLUE, GREEN : Cut/etch surface. Adjust speed/power to get the best result.
BLACK: Raster scan

My process:
Decide on which front you want. Cut one front, one back, one rete, and one blank. The front and back are cut on clear acrylic, The rete and the blank cut with an opaque acrylic.

Print the two stl files.

Select one of the climate plates closest to your latitude and print it out. Cut it out, laminating it is not necessary, but will cut down wear.

When the bits are assembled:

There are two holes at the top of the astrolabe, you want to place the screw in the lower one. Place a screw through the front, blank, and back and tighten on a locknut. do the same for the hole at to bottom of the astrolabe.

Cut out the hole marked on the climate plate. place the climate plate in the center hollow of the front, being careful to align it properly. lift an edge an place a small piece of tape under it to keep it from turning in use.

Next, place a long screw through the center hole of the alidade arm, then through the center of the back of the astrolabe. Then place the rete over the screw and set it into the hollow over the climate plate. Then place the rule arm over the screw, and tighten down a locknut to hold everything together. The arms and rete should move freely, but not loosely.

Finally place a ring through the top-most hole.

Links:
My blog: http://www.astrolabeproject.com/
Class handout: http://astrolabeproject.com/downloads/Astrolabe_in_Theory_and_Practice.pdf
Simulator: http://www.astrolabeproject.com/sim/astrolabe/sim.html