Introduction: Custom Etched Granite Cut
Step 1: Cutting your stone (granite)
1) Design vectors, lead ins, etc (make lead ins a little long for potential blowouts on the back of the stone)
2) Drop water jet down to 15-20,000 PSI for pierce only. Pierce hole(s) on starting point(s) all the way through stone.
3) Crank back up to 50-60,000 for cut.
4) Cut very slowly (My cut ranged from 0.15 to 0.7 inches per minute. Mine usually sat at about 0.3 in/min.) The slow cut is required for a nice even edge. My granite was about 1.25" thick.
Step 2: Laser etch and cut clear acrylic
1) Test your images on identical material. Apart from laser settings, may have to alter photos in a raster program (PhotoShop, Corel PhotoPaint,etc)
Keep an eye on:
2) Import your etch and cut as one file.
3) Cut (do not etch, disable the etch function) the acrylic
a. Keep protective paper covering acrylic to prevent burn marks
b. Do all cut lines in one run
c. Leave file in same place.
3) Remove protective covering and etch images and/or lettering by placing the piece back into the negative space.
Step 3: Laser cut (and etch) bolts.
1) Cut and etch bolt heads using the same order of operations as the main acrylic cut.
2) Cut circles to fit into the holes of the main acrylic cut.
-- Increase your circle size to correct for laser “tool width.” Mine was corrected by 0.007”; from 0.25” to 0.257”
Step 4: Fasten bolts
1) Scratch granite at “bolt” contact points
2) Use acrylic weld solvent to attach the circles to the "bolt" heads
3) Epoxy the tip of the “bolts” and carefully place the bolts through the acrylic onto the roughed granite face.
4) Very carefully use two flat boards to clamp the acrylic bolts down to the granite while the epoxy sets and cures.
Step 5: Make a stand
1) Design a thick acrylic stand (I used 1/2") that slots together and holds the stone evenly
2) Test: (I used cardboard). Test at same scale (eg. Four layers of cardboard for 1/2" acrylic) to make sure the part rests as it should
3) Test connecting points with small cuts of acrylic. Again – "tool width" correction for the laser. This time I went -0.006” to make them fit perfectly snug.
4) If you have images or text to etch onto the stand, use same order as other acrylic cuts: cut with paper on, etch same file with paper removed.