This volt pattern works better to me
volt_pattern := {1: "0.0,12.4,81", 2: "0.0,11.0,81", 3: "-1.5,13.8,81"
,4: "-1.7,11.9,81", 5: "-1.7,13.6,81", 6: "-2.5,13.6,81"
,7: "-2.5,7.7,81", 8: "-2,5.3,81", 9: "-2.5,5.2,81"
,10: "-2.0,4.6,81", 11: "1.0,3.8,81", 12: "2.7,1.2,81"
,13: "4.0,6.8,81", 14: "6.0,4.6,81", 15: "5.0,3.0,81"
,16: "5.0,4.3,81", 17: "5.0,3.2,81", 18: "5.0,2.8,81"
,19: "4.0,1.7,81", 20: "4.1,8.3,81", 21: "3.0,2.2,81"
,22: "0.0,0.0,81", 23: "0.0,0.0,81", 24: "0.0,0.0,81"
,25: "0.0,0.0,81", 26: "0.0,0.0,81", 27: "0.0,0.0,81"}