Cutting out parts with laser

List of Parts

Materials/Parts
Note: although the OpenROV 2.3 design is metric, most stores in the US will only sell acrylic in English units, so we've provided dimensions in inches for this section.


 * The three files with the layouts that have to be cut (available on our github repository)
 * Blue parts (main body and echassis) - PDF, DXF, CDR
 * White parts (tube caps and prop guard) - PDF, DXF, CDR
 * Clear parts (tube caps) - PDF, DXF, CDR
 * One 24" x 18" sheet of 1/8" (actually .118") thick translucent blue acrylic.
 * One 24" x 12" sheet of 1/8" thick white acrylic
 * One 24" x 12" sheet of 1/8" thick clear acrylic
 * One 4" OD, 3.75" ID (1/8" wall thickness) by greater then 7in (180mm) long piece of clear cast acrylic tubing (Note, that tube must be CAST rather then extruded, as extruded tubes usually have longitudinal distortion which would interfere with camera image)
 * One 3.25" OD, 3" ID (1/8" wall thickness) 1' long piece of clear cast acrylic tubing

Note: European suppliers sell slightly different sizes especially for the tubes, an updated bill of materials for European makes will come soon

Tools

 * Laser cutter connected to a computer (we use a 24" x 18" Epilog 60W Helix)
 * Chop saw
 * Masking tape

Assembly Notes

 * 24" x 18" sheet will be used for main OpenROV structural parts and the two 24" x 12" sheets will be used for end cap components
 * Remove backing on side of plastic that will be facing the laser source should be removed to prevent flame
 * Assure that outline of ROV parts will be cut as vectors while OpenROV logo and serial number are set to be rastered
 * For 60W Epilog Helix laser cutter, settings should be 60% speed at 30% power for raster, and 18% speed at 90% power (5000kHz frequency) for vector
 * Focus laser toward top of plastic sheet to assure clear rastering
 * Cut out test piece with both raster and vector components in upper left corner of sheet before starting to assure settings and adjustments are correct
 * The main parts pattern (cut out from the 24" x 18" sheet) should take about 8 minuets to finish
 * The end cap parts pattern (on the 24" x 12" sheet) should take bout 4 minutes
 * Each OpenROV has a unique serial number. If you plan to laser cut your own OpenROV structure, please request a serial number by sending an email with the subject heading "SERIAL REQUEST" to [mailto:Info@OpenROV.com Info@OpenROV.com] several days before you plan to cut.  Once we get your request, we will issue a serial number which will be valid for the next three days.  If you don't cut during that time, just let us know and we can reissue you a new number.

Procedure

 * 1) Remove backing from one side of 24" by 18" acrylic sheet and place on laser cutter platform with backing-less side facing up
 * 2) Focus laser to top surface of sheet
 * 3) Cut out test piece (such ) in upper left hand corner and verify quality
 * 4) At high speed, verify that laser path stays on sheet by running with pointer on and laser off (lid open)
 * 5) Cut out Laser Cut Pattern
 * 6) Inspect all pieces for quality.  Whipe clean rastered area with moist rag
 * 7) Repeat steps 4 and 5 for the two 24" x 12" sheets, but for Endcap pattern first on the white and then the clear sheet
 * 8) Wrap masking tape around acrylic tube so that it's center is about 175mm from one end.  Masking tape will hold a mark and also prevent chipping during the cut
 * 9) Mark the masking tape at exactly 175mm from the end of the acrylic tube
 * 10) Use a chop saw to (slowly) cut the acrylic tube at the mark
 * 11) Deburr edges with fine sandpaper when done and remove tape