Site Last Updated 8/18/14
Tool Nose Radius Compensation Calculating
Face to Angle or Angle to Face
1) Tool Radius x Sin Angle A = Side a1
2) Tool Radius x Cos A = Side b1
3) Tool Radius -
4) Side a2 x Tan Angle A = Side a3
5) Subtract Side a3 from Side b1 = Side b2
6) Subtract Side b2 from Tool Radius = Offset Amount
Note: For a lathe multiply the X offset amount by 2
You have a cnc lathe part like above, that has a 30° chamfer blending to a face. Obviously there is no compensation needed for the Z axis but you do need to calculate tool nose radius compensation for the X axis if you want to make an accurate angle. Lets say we are using a turning tool with a 1/64(.0156) tool nose radius on it. Using the formula above lets calculate the X compensation:
1) Tool Radius (.0156) x 30Sin = .0078(side a1)
2) Tool Radius (.0156) x 30Cos = .0135(side b1)
3) Tool Radius (.0156) -
4) .0078(side a2) x 30Tan = .0045(side a3)
5) .0135(side b1) -
6) Tool Radius -
7) .0066 x 2 = .0132 (X Tool Tip Compensation)
So the compensation in this case would be:
Z = 0 Compensation
X = -
As you can see above, calculating the tool nose radius compensation for a cnc lathe part can be time consuming and a bit of a pain. Fortunately there is an easy alternative:
“Simple Lathe Cam” is now included in the Web Machinist Software Program. (Actual Screen Shots Below)
With Simple Lathe Cam you can easily calculate tool nose radius compensation, radius angle corners and fillets as seen in the example above. Simple Lathe Cam also can generate the CNC lathe program too!
You can change the feed direction, add a fillet radius or a corner radius and have the G code program generated using “R” or “I,K” codes for radius calculations. Very easy to use and extremely accurate!
The above screen shots are of the simplest Tool Tip Radius Calculations. By clicking any of the tools you are given the option of just getting the tool nose radius compensation calculations as seen above or the fully generated G code program as seen in the screen shot below.
Simple Lathe Cam is the simple but powerful cnc lathe Cad/Cam tool nose radius compensation software on the market. You can easily calculate the tool nose radius compensation for the most common external angles and internal angles with or without radii and fillets. Simple Lathe Cam can even generate the G code program for your cnc lathe.
Web Machinist Software: