Definition of shim segments
cc2t
cc2b
cct
cc2int
ccb
ccint
bc2tl
bc2tru
bc2trl
bc2bru
bc2int
bc2brl
bc2bl
bcint
bctl
bctru
bctrl
bctrl
bcbrl
bcbl
aaint
aatl
aabl
aatr
aabr
ab2int
ab2tl
ab2tru
ab2trl
ab2br
ab2bl
abint
abtl
abtr
abbru
abbrl
abbl
-60 deg
+60 deg
0 deg
cc2inb
bc2inb
ab2inb
aainb
ccinb
bcinb
abinb