Ok, I give up. 7 start thread

I used Fusion 360 to program it.

Pitch 0.115
OD 1.870
Depth .110
Width of gear .610
Lead 1.2422
7 Start

I calculated the lead by (1/0.115) / 7 = 1.2422. Maybe this is not correct. Maybe it should be just 0.115, I'll try that number and see what happens.

OK, in simulation that seems to be a bit fine. Where are you getting the 0.115? Is this crest to crest on the same thread?
 
Yes the .115 is the crest of the thread.
 
OK, maybe this will work. Same parameters as above, except with a 0.115 lead.

%
O1009 (TEST)
N10 G98 G18
N15 G20
N20 G50 S100
N25 G28 U0.

(THREAD1)
N30 T0100
N35 G54
N40 M8
N45 G99
N50 G97 S30 M4 (Spindle Clockwise)
N55 G0 X2.8 Z0.23
N60 G0 X1.8065
N65 G32 Z-0.755 F0.115
N70 G0 X2.8
N75 Z0.23
N80 X1.7802
N85 G32 Z-0.755 F0.115
N90 G0 X2.8
N95 Z0.23
N100 X1.76
N105 G32 Z-0.755 F0.115
N110 G0 X2.8
N115 Z0.23
N120 X1.743
N125 G32 Z-0.755 F0.115
N130 G0 X2.8
N135 Z0.23
N140 X1.728
N145 G32 Z-0.755 F0.115
N150 G0 X2.8
N155 Z0.23
N160 X1.7144
N165 G32 Z-0.755 F0.115
N170 G0 X2.8
N175 Z0.23
N180 X1.702
N185 G32 Z-0.755 F0.115
N190 G0 X2.8
N195 Z0.23
N200 X1.6904
N205 G32 Z-0.755 F0.115
N210 G0 X2.8
N215 Z0.23
N220 X1.6795
N225 G32 Z-0.755 F0.115
N230 G0 X2.8
N235 Z0.23
N240 X1.6692
N245 G32 Z-0.755 F0.115
N250 G0 X2.8
N255 Z0.23
N260 X1.6594
N265 G32 Z-0.755 F0.115
N270 G0 X2.8
N275 Z0.23
N280 X1.65
N285 G32 Z-0.755 F0.115
N290 G0 X2.8
N295 Z0.2464
N300 X1.8065
N305 G32 Z-0.755 F0.115
N310 G0 X2.8
N315 Z0.2464
N320 X1.7802
N325 G32 Z-0.755 F0.115
N330 G0 X2.8
N335 Z0.2464
N340 X1.76
N345 G32 Z-0.755 F0.115
N350 G0 X2.8
N355 Z0.2464
N360 X1.743
N365 G32 Z-0.755 F0.115
N370 G0 X2.8
N375 Z0.2464
N380 X1.728
N385 G32 Z-0.755 F0.115
N390 G0 X2.8
N395 Z0.2464
N400 X1.7144
N405 G32 Z-0.755 F0.115
N410 G0 X2.8
N415 Z0.2464
N420 X1.702
N425 G32 Z-0.755 F0.115
N430 G0 X2.8
N435 Z0.2464
N440 X1.6904
N445 G32 Z-0.755 F0.115
N450 G0 X2.8
N455 Z0.2464
N460 X1.6795
N465 G32 Z-0.755 F0.115
N470 G0 X2.8
N475 Z0.2464
N480 X1.6692
N485 G32 Z-0.755 F0.115
N490 G0 X2.8
N495 Z0.2464
N500 X1.6594
N505 G32 Z-0.755 F0.115
N510 G0 X2.8
N515 Z0.2464
N520 X1.65
N525 G32 Z-0.755 F0.115
N530 G0 X2.8
N535 Z0.2629
N540 X1.8065
N545 G32 Z-0.755 F0.115
N550 G0 X2.8
N555 Z0.2629
N560 X1.7802
N565 G32 Z-0.755 F0.115
N570 G0 X2.8
N575 Z0.2629
N580 X1.76
N585 G32 Z-0.755 F0.115
N590 G0 X2.8
N595 Z0.2629
N600 X1.743
N605 G32 Z-0.755 F0.115
N610 G0 X2.8
N615 Z0.2629
N620 X1.728
N625 G32 Z-0.755 F0.115
N630 G0 X2.8
N635 Z0.2629
N640 X1.7144
N645 G32 Z-0.755 F0.115
N650 G0 X2.8
N655 Z0.2629
N660 X1.702
N665 G32 Z-0.755 F0.115
N670 G0 X2.8
N675 Z0.2629
N680 X1.6904
N685 G32 Z-0.755 F0.115
N690 G0 X2.8
N695 Z0.2629
N700 X1.6795
N705 G32 Z-0.755 F0.115
N710 G0 X2.8
N715 Z0.2629
N720 X1.6692
N725 G32 Z-0.755 F0.115
N730 G0 X2.8
N735 Z0.2629
N740 X1.6594
N745 G32 Z-0.755 F0.115
N750 G0 X2.8
N755 Z0.2629
N760 X1.65
N765 G32 Z-0.755 F0.115
N770 G0 X2.8
N775 Z0.2793
N780 X1.8065
N785 G32 Z-0.755 F0.115
N790 G0 X2.8
N795 Z0.2793
N800 X1.7802
N805 G32 Z-0.755 F0.115
N810 G0 X2.8
N815 Z0.2793
N820 X1.76
N825 G32 Z-0.755 F0.115
N830 G0 X2.8
N835 Z0.2793
N840 X1.743
N845 G32 Z-0.755 F0.115
N850 G0 X2.8
N855 Z0.2793
N860 X1.728
N865 G32 Z-0.755 F0.115
N870 G0 X2.8
N875 Z0.2793
N880 X1.7144
N885 G32 Z-0.755 F0.115
N890 G0 X2.8
N895 Z0.2793
N900 X1.702
N905 G32 Z-0.755 F0.115
N910 G0 X2.8
N915 Z0.2793
N920 X1.6904
N925 G32 Z-0.755 F0.115
N930 G0 X2.8
N935 Z0.2793
N940 X1.6795
N945 G32 Z-0.755 F0.115
N950 G0 X2.8
N955 Z0.2793
N960 X1.6692
N965 G32 Z-0.755 F0.115
N970 G0 X2.8
N975 Z0.2793
N980 X1.6594
N985 G32 Z-0.755 F0.115
N990 G0 X2.8
N995 Z0.2793
N1000 X1.65
N1005 G32 Z-0.755 F0.115
N1010 G0 X2.8
N1015 Z0.2957
N1020 X1.8065
N1025 G32 Z-0.755 F0.115
N1030 G0 X2.8
N1035 Z0.2957
N1040 X1.7802
N1045 G32 Z-0.755 F0.115
N1050 G0 X2.8
N1055 Z0.2957
N1060 X1.76
N1065 G32 Z-0.755 F0.115
N1070 G0 X2.8
N1075 Z0.2957
N1080 X1.743
N1085 G32 Z-0.755 F0.115
N1090 G0 X2.8
N1095 Z0.2957
N1100 X1.728
N1105 G32 Z-0.755 F0.115
N1110 G0 X2.8
N1115 Z0.2957
N1120 X1.7144
N1125 G32 Z-0.755 F0.115
N1130 G0 X2.8
N1135 Z0.2957
N1140 X1.702
N1145 G32 Z-0.755 F0.115
N1150 G0 X2.8
N1155 Z0.2957
N1160 X1.6904
N1165 G32 Z-0.755 F0.115
N1170 G0 X2.8
N1175 Z0.2957
N1180 X1.6795
N1185 G32 Z-0.755 F0.115
N1190 G0 X2.8
N1195 Z0.2957
N1200 X1.6692
N1205 G32 Z-0.755 F0.115
N1210 G0 X2.8
N1215 Z0.2957
N1220 X1.6594
N1225 G32 Z-0.755 F0.115
N1230 G0 X2.8
N1235 Z0.2957
N1240 X1.65
N1245 G32 Z-0.755 F0.115
N1250 G0 X2.8
N1255 Z0.3121
N1260 X1.8065
N1265 G32 Z-0.755 F0.115
N1270 G0 X2.8
N1275 Z0.3121
N1280 X1.7802
N1285 G32 Z-0.755 F0.115
N1290 G0 X2.8
N1295 Z0.3121
N1300 X1.76
N1305 G32 Z-0.755 F0.115
N1310 G0 X2.8
N1315 Z0.3121
N1320 X1.743
N1325 G32 Z-0.755 F0.115
N1330 G0 X2.8
N1335 Z0.3121
N1340 X1.728
N1345 G32 Z-0.755 F0.115
N1350 G0 X2.8
N1355 Z0.3121
N1360 X1.7144
N1365 G32 Z-0.755 F0.115
N1370 G0 X2.8
N1375 Z0.3121
N1380 X1.702
N1385 G32 Z-0.755 F0.115
N1390 G0 X2.8
N1395 Z0.3121
N1400 X1.6904
N1405 G32 Z-0.755 F0.115
N1410 G0 X2.8
N1415 Z0.3121
N1420 X1.6795
N1425 G32 Z-0.755 F0.115
N1430 G0 X2.8
N1435 Z0.3121
N1440 X1.6692
N1445 G32 Z-0.755 F0.115
N1450 G0 X2.8
N1455 Z0.3121
N1460 X1.6594
N1465 G32 Z-0.755 F0.115
N1470 G0 X2.8
N1475 Z0.3121
N1480 X1.65
N1485 G32 Z-0.755 F0.115
N1490 G0 X2.8
N1495 Z0.3286
N1500 X1.8065
N1505 G32 Z-0.755 F0.115
N1510 G0 X2.8
N1515 Z0.3286
N1520 X1.7802
N1525 G32 Z-0.755 F0.115
N1530 G0 X2.8
N1535 Z0.3286
N1540 X1.76
N1545 G32 Z-0.755 F0.115
N1550 G0 X2.8
N1555 Z0.3286
N1560 X1.743
N1565 G32 Z-0.755 F0.115
N1570 G0 X2.8
N1575 Z0.3286
N1580 X1.728
N1585 G32 Z-0.755 F0.115
N1590 G0 X2.8
N1595 Z0.3286
N1600 X1.7144
N1605 G32 Z-0.755 F0.115
N1610 G0 X2.8
N1615 Z0.3286
N1620 X1.702
N1625 G32 Z-0.755 F0.115
N1630 G0 X2.8
N1635 Z0.3286
N1640 X1.6904
N1645 G32 Z-0.755 F0.115
N1650 G0 X2.8
N1655 Z0.3286
N1660 X1.6795
N1665 G32 Z-0.755 F0.115
N1670 G0 X2.8
N1675 Z0.3286
N1680 X1.6692
N1685 G32 Z-0.755 F0.115
N1690 G0 X2.8
N1695 Z0.3286
N1700 X1.6594
N1705 G32 Z-0.755 F0.115
N1710 G0 X2.8
N1715 Z0.3286
N1720 X1.65
N1725 G32 Z-0.755 F0.115
N1730 G0 X2.8

N1735 M9
N1740 G28 U0.
N1745 G28 W0.
N1750 M30
%
 
Last edited:
Maybe this will work better. Uses a 0.805 lead. 0.115 x 7 = 0.805 You can't just change the pitch in the G code. As the pitch changes, all of the G code changes. You have to repost the G code when you change the pitch.

%
O1010 (TEST)
N10 G98 G18
N15 G20
N20 G50 S100
N25 G28 U0.

(THREAD1)
N30 T0100
N35 G54
N40 M8
N45 G99
N50 G97 S30 M4 (Spindle Clockwise)
N55 G0 X2.8 Z0.23
N60 G0 X1.8065
N65 G32 Z-0.755 F0.805
N70 G0 X2.8
N75 Z0.23
N80 X1.7802
N85 G32 Z-0.755 F0.805
N90 G0 X2.8
N95 Z0.23
N100 X1.76
N105 G32 Z-0.755 F0.805
N110 G0 X2.8
N115 Z0.23
N120 X1.743
N125 G32 Z-0.755 F0.805
N130 G0 X2.8
N135 Z0.23
N140 X1.728
N145 G32 Z-0.755 F0.805
N150 G0 X2.8
N155 Z0.23
N160 X1.7144
N165 G32 Z-0.755 F0.805
N170 G0 X2.8
N175 Z0.23
N180 X1.702
N185 G32 Z-0.755 F0.805
N190 G0 X2.8
N195 Z0.23
N200 X1.6904
N205 G32 Z-0.755 F0.805
N210 G0 X2.8
N215 Z0.23
N220 X1.6795
N225 G32 Z-0.755 F0.805
N230 G0 X2.8
N235 Z0.23
N240 X1.6692
N245 G32 Z-0.755 F0.805
N250 G0 X2.8
N255 Z0.23
N260 X1.6594
N265 G32 Z-0.755 F0.805
N270 G0 X2.8
N275 Z0.23
N280 X1.65
N285 G32 Z-0.755 F0.805
N290 G0 X2.8
N295 Z0.345
N300 X1.8065
N305 G32 Z-0.755 F0.805
N310 G0 X2.8
N315 Z0.345
N320 X1.7802
N325 G32 Z-0.755 F0.805
N330 G0 X2.8
N335 Z0.345
N340 X1.76
N345 G32 Z-0.755 F0.805
N350 G0 X2.8
N355 Z0.345
N360 X1.743
N365 G32 Z-0.755 F0.805
N370 G0 X2.8
N375 Z0.345
N380 X1.728
N385 G32 Z-0.755 F0.805
N390 G0 X2.8
N395 Z0.345
N400 X1.7144
N405 G32 Z-0.755 F0.805
N410 G0 X2.8
N415 Z0.345
N420 X1.702
N425 G32 Z-0.755 F0.805
N430 G0 X2.8
N435 Z0.345
N440 X1.6904
N445 G32 Z-0.755 F0.805
N450 G0 X2.8
N455 Z0.345
N460 X1.6795
N465 G32 Z-0.755 F0.805
N470 G0 X2.8
N475 Z0.345
N480 X1.6692
N485 G32 Z-0.755 F0.805
N490 G0 X2.8
N495 Z0.345
N500 X1.6594
N505 G32 Z-0.755 F0.805
N510 G0 X2.8
N515 Z0.345
N520 X1.65
N525 G32 Z-0.755 F0.805
N530 G0 X2.8
N535 Z0.46
N540 X1.8065
N545 G32 Z-0.755 F0.805
N550 G0 X2.8
N555 Z0.46
N560 X1.7802
N565 G32 Z-0.755 F0.805
N570 G0 X2.8
N575 Z0.46
N580 X1.76
N585 G32 Z-0.755 F0.805
N590 G0 X2.8
N595 Z0.46
N600 X1.743
N605 G32 Z-0.755 F0.805
N610 G0 X2.8
N615 Z0.46
N620 X1.728
N625 G32 Z-0.755 F0.805
N630 G0 X2.8
N635 Z0.46
N640 X1.7144
N645 G32 Z-0.755 F0.805
N650 G0 X2.8
N655 Z0.46
N660 X1.702
N665 G32 Z-0.755 F0.805
N670 G0 X2.8
N675 Z0.46
N680 X1.6904
N685 G32 Z-0.755 F0.805
N690 G0 X2.8
N695 Z0.46
N700 X1.6795
N705 G32 Z-0.755 F0.805
N710 G0 X2.8
N715 Z0.46
N720 X1.6692
N725 G32 Z-0.755 F0.805
N730 G0 X2.8
N735 Z0.46
N740 X1.6594
N745 G32 Z-0.755 F0.805
N750 G0 X2.8
N755 Z0.46
N760 X1.65
N765 G32 Z-0.755 F0.805
N770 G0 X2.8
N775 Z0.575
N780 X1.8065
N785 G32 Z-0.755 F0.805
N790 G0 X2.8
N795 Z0.575
N800 X1.7802
N805 G32 Z-0.755 F0.805
N810 G0 X2.8
N815 Z0.575
N820 X1.76
N825 G32 Z-0.755 F0.805
N830 G0 X2.8
N835 Z0.575
N840 X1.743
N845 G32 Z-0.755 F0.805
N850 G0 X2.8
N855 Z0.575
N860 X1.728
N865 G32 Z-0.755 F0.805
N870 G0 X2.8
N875 Z0.575
N880 X1.7144
N885 G32 Z-0.755 F0.805
N890 G0 X2.8
N895 Z0.575
N900 X1.702
N905 G32 Z-0.755 F0.805
N910 G0 X2.8
N915 Z0.575
N920 X1.6904
N925 G32 Z-0.755 F0.805
N930 G0 X2.8
N935 Z0.575
N940 X1.6795
N945 G32 Z-0.755 F0.805
N950 G0 X2.8
N955 Z0.575
N960 X1.6692
N965 G32 Z-0.755 F0.805
N970 G0 X2.8
N975 Z0.575
N980 X1.6594
N985 G32 Z-0.755 F0.805
N990 G0 X2.8
N995 Z0.575
N1000 X1.65
N1005 G32 Z-0.755 F0.805
N1010 G0 X2.8
N1015 Z0.69
N1020 X1.8065
N1025 G32 Z-0.755 F0.805
N1030 G0 X2.8
N1035 Z0.69
N1040 X1.7802
N1045 G32 Z-0.755 F0.805
N1050 G0 X2.8
N1055 Z0.69
N1060 X1.76
N1065 G32 Z-0.755 F0.805
N1070 G0 X2.8
N1075 Z0.69
N1080 X1.743
N1085 G32 Z-0.755 F0.805
N1090 G0 X2.8
N1095 Z0.69
N1100 X1.728
N1105 G32 Z-0.755 F0.805
N1110 G0 X2.8
N1115 Z0.69
N1120 X1.7144
N1125 G32 Z-0.755 F0.805
N1130 G0 X2.8
N1135 Z0.69
N1140 X1.702
N1145 G32 Z-0.755 F0.805
N1150 G0 X2.8
N1155 Z0.69
N1160 X1.6904
N1165 G32 Z-0.755 F0.805
N1170 G0 X2.8
N1175 Z0.69
N1180 X1.6795
N1185 G32 Z-0.755 F0.805
N1190 G0 X2.8
N1195 Z0.69
N1200 X1.6692
N1205 G32 Z-0.755 F0.805
N1210 G0 X2.8
N1215 Z0.69
N1220 X1.6594
N1225 G32 Z-0.755 F0.805
N1230 G0 X2.8
N1235 Z0.69
N1240 X1.65
N1245 G32 Z-0.755 F0.805
N1250 G0 X2.8
N1255 Z0.805
N1260 X1.8065
N1265 G32 Z-0.755 F0.805
N1270 G0 X2.8
N1275 Z0.805
N1280 X1.7802
N1285 G32 Z-0.755 F0.805
N1290 G0 X2.8
N1295 Z0.805
N1300 X1.76
N1305 G32 Z-0.755 F0.805
N1310 G0 X2.8
N1315 Z0.805
N1320 X1.743
N1325 G32 Z-0.755 F0.805
N1330 G0 X2.8
N1335 Z0.805
N1340 X1.728
N1345 G32 Z-0.755 F0.805
N1350 G0 X2.8
N1355 Z0.805
N1360 X1.7144
N1365 G32 Z-0.755 F0.805
N1370 G0 X2.8
N1375 Z0.805
N1380 X1.702
N1385 G32 Z-0.755 F0.805
N1390 G0 X2.8
N1395 Z0.805
N1400 X1.6904
N1405 G32 Z-0.755 F0.805
N1410 G0 X2.8
N1415 Z0.805
N1420 X1.6795
N1425 G32 Z-0.755 F0.805
N1430 G0 X2.8
N1435 Z0.805
N1440 X1.6692
N1445 G32 Z-0.755 F0.805
N1450 G0 X2.8
N1455 Z0.805
N1460 X1.6594
N1465 G32 Z-0.755 F0.805
N1470 G0 X2.8
N1475 Z0.805
N1480 X1.65
N1485 G32 Z-0.755 F0.805
N1490 G0 X2.8
N1495 Z0.92
N1500 X1.8065
N1505 G32 Z-0.755 F0.805
N1510 G0 X2.8
N1515 Z0.92
N1520 X1.7802
N1525 G32 Z-0.755 F0.805
N1530 G0 X2.8
N1535 Z0.92
N1540 X1.76
N1545 G32 Z-0.755 F0.805
N1550 G0 X2.8
N1555 Z0.92
N1560 X1.743
N1565 G32 Z-0.755 F0.805
N1570 G0 X2.8
N1575 Z0.92
N1580 X1.728
N1585 G32 Z-0.755 F0.805
N1590 G0 X2.8
N1595 Z0.92
N1600 X1.7144
N1605 G32 Z-0.755 F0.805
N1610 G0 X2.8
N1615 Z0.92
N1620 X1.702
N1625 G32 Z-0.755 F0.805
N1630 G0 X2.8
N1635 Z0.92
N1640 X1.6904
N1645 G32 Z-0.755 F0.805
N1650 G0 X2.8
N1655 Z0.92
N1660 X1.6795
N1665 G32 Z-0.755 F0.805
N1670 G0 X2.8
N1675 Z0.92
N1680 X1.6692
N1685 G32 Z-0.755 F0.805
N1690 G0 X2.8
N1695 Z0.92
N1700 X1.6594
N1705 G32 Z-0.755 F0.805
N1710 G0 X2.8
N1715 Z0.92
N1720 X1.65
N1725 G32 Z-0.755 F0.805
N1730 G0 X2.8

N1735 M9
N1740 G28 U0.
N1745 G28 W0.
N1750 M30
%
 
Tried both files.

Pic is .805 feed.

The .805 still seems steep, or fast. But oh so close.

I guess I need to look into fusion.

TWOGEARS.jpg
 
OK, I think we now know what numbers to plug in. Crest to Crest distance times the Number of Starts = pitch. So, double check your crest to crest dimension. Any error multiplies by the number of starts.

Have you got a comparator? I have a small hand held one, but not a real one.
 
Well it looks like you are getting closer
 
Getting closer and closer as the hours go by.
Sure is an elusive problem/challenge.
 
Yes closer than I've been in over a month of playing width it. Very elusive to say the least. I'm surprised that Jim can get so close using fusion and I'm not even in the ballpark with mastercam. But in mastercam's defense, I'm sure it's operator error with it more than anything.

Figuring out the formula like you did is great. I've read so many how to's on multi start it made my head spin.

I don't have a comparator. I didn't even realize they hand hand held ones. I'm more than willing to buy one.

So the hand held ones are really just a magnifier and you compare the part to a scale to get the dimensions? I've never use a comparator before. I kept begging them to get one at work, but they said they couldn't afford it. Yeah.........right.

I just tried to use my 10x loupe and I just can't hold a scale and the loupe steady enough to get a measurement.

Can I just adjust the feed a little at the time? Or would you have to do it in the cam program?
 
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