Defibrillator III  by Bob Keller
GemCad Ray Traces for RI = 1.760
Random Model Cosine Model ISO Model
Defibrillator III
Designed by Bob Keller December 2001, Revised April 2015
A CAM Style Heart for 120 gears suitable for Spinel, Garnet, Corundum...
Angles for R.I. = 1.76055 + 19 girdles = 74 facets
1-fold mirror-image symmetry120 index
L/W = 1.012 T/W = 0.583 U/W = 0.528 P/W = 0.411 C/W = 0.146
Vol./W^3 = 0.184Brightness at 0° tilt for RI = 1.76 COS = 72.3 ISO = 90.6
cp36.0015-45-75-105Cut to equal depth to establish center point
142.62011-109Cut facets 1-10 to centerpoint
940.21 057-063 
g190.00011-109Set size, establish lower girdle line
g290.00013-107Meet g1.1.2
g390.00015-105Meet g2.2.3
g490.00019-101Meet g3.3.4
g590.00021-099Meet g4.4.5
g690.00029-091Meet g5.5.6
g790.00037-083Meet g6.6.7
g890.00045-075Meet g7.7.8
g990.00057-063Meet g8.8.9
g1090.00060Meet g9.9.10
a37.26°011-109Match g1, establish upper girdle line
b38.68°013-107Meet a.g1.g2
c38.92°015-105Meet b.g2.g3
d38.82°019-101Meet c.g3.g4
e38.06°021-099Meet d.g4.g5
f35.10°029-091Meet e.g5.g6
g33.10°037-083Meet f.g6.g7
h32.54°045-075Meet g.g7.g8
i34.77°057-063Meet h.g8.g9
j37.69°060Meet i.g9.g10
k36.96°012-108Meet g1.a.b.g2
l36.25°017-103Meet g3.c.d.g4
m31.54°025-095Meet g5.e.f.g6
n28.18°041-079Meet g7.g.h.g8
o30.72°014-106Meet k.b.c.l, k.a.a.k
p28.20°023-097Meet l.d.e.m
q22.18°038-082Meet m.f.g.n
r28.43°055-065Meet n.h.i, i.j.i
t 0.00°TableMeet k.a.a.k, o.l.p, p.m.q, others

Download PDF format printer friendly cutting instructions: [ Download Icon Defibrillator III Printer Icon ]

Download the GemCad format design file: [ Download Icon defib3.gem ]

I designed Defibrillator III for a for a deep red pyrope garnet. This design is pretty bright as hearts go and is a good match for medium to deep saturated materials with RIs in the spinel-garnet-corundum range.

Begin the pavilion by carefully cutting four facets on indexes 15-45-75-105 at 36.00° to equal depth to establish a centered culet point. These four center point "finder" facets get cut away as pavilion facets 1-10 are subsequently cut to meet at this center point. The simple faceting in the "head" area on Defibrillator III should be facilitating if you are into vee notching your hearts.

Index of Gem Designs

Perfect Transfer Index

Table of Contents

Bob Keller