1" - 8 Thread Single Start
Standard start codes
Tool, Spindle Speed, Coolant, Etc.
N110 G0 X1.2 Z.5 Initial Referance Move (Clearence Position)
N112 G76 X.8492 (Minor Dia) Z-6.0 ( Length Of Thread ) I0.0 (Tapper)
K .0754 (Major - Minor / 2) Radial Distance From Minor To Major
D.010 Depth Of First Cut A60 Included Angle Of Insert Tip
F.125000 Feed Per Rev ( Some Machines Require E as Feed Call For
Thread) (Six Place Decimal)
1" - 8 Thread Double Start
SAME AS ABOVE FOR INITIAL LEAD
Then
N114 G0 W.0625 (Incremental) Or Z.5625 (Absloute)
N116 (SAME AS LINE #112 )
OPTIAN 1
If your thread is.023 smaller on diameter at the 6" dimension
Change your I0 to I-.0115 This will make the thread tapper as it travles.
You figure this by measuring the pitch at the front and the pitch at the rear of the thread take these two numbers and subtract from each other. Then devide in half. If the thread is smaller at the rear use a negative number if it is larger in the front use a positive.
OPTION 2
If the taper is caused by a Part or tool deflection you can follow up with a G32 Line (NOTE change your A60 to a A0 in the G76 line if your are not good at figuring trig formulas) A60 causes your tool to move in at a 30 Deg angle every time it takes a new pass This is to keep the major chip load on one side of the tool. Most tools cut best with a chip load on only one side of the tool. A0 makes it so the X axis will move in but the Z will not adjust at all.
After the G76 line Plce a line similar to this
N114G0 X.8492 (Rapids from canned cycle return point to Minor Dia.)
N116 G32 Z-6.0 F.12500
N118 G0 X1.2
N120 G0 Z.5
N122 G32 Z-6.0 F.12500
N124 G0 X1.2
N126 G0 Z.5
Repete as needed
You can also start above in your X axis and move down on every pass
By placing the above lines after your canned cycle it creates dead passes at the Basic Minor Diameter
If You need to make a double lead thread
Use The 1" - 8 Double Lead Lines seen above in post after the dead cuts
and once again follow up with G32 lines or adjust the I0 to compensate for pitch deviation.
Hope this helps  |