G02, G03
OBJECTIVES
After completing this unit, you should be able to:
- Identify and describe G02 and G03 on a CNC turning center
- Identify and describe I and K-Method for arcs on a CNC turning center
- Identify and describe U and W with G02/G03 blocks
G02, G03
Variables List:
G02 and G03 codes are used to specify a circular motion (CW or CCW) of the linear axes (Circular motion is possible in the X and Z axes).
The X and Z values are used to specify the end point of the motion and can use either absolute (X and Z) or incremental motion (U and W). X, Z are controlled with rapid movement G 01.
Codes for cutting an ARC on a Lathe
There are two methods to write for Arcs on the lathe.
Read this short piece from HAAS on G02 CW / G03 CCW Circular Interpolation Motion.
R-Method
When R-method is used, the code uses the direction, end point, and radius. The machine will make the cut. It will not stop for a mistake. If there is conflicting data will try to make the cut.
We do not use the R-method often.
I and K-Method
When the I and K-Method is used, the CNC machine with an error message. The CNC prevents a mistake in the cut. The I and K-method is sfaet to make Arcs.
I and K are the same as rise over run used in mathematics.
Think about features on both sides of the axis
X0, Z 1.75
X2, Z -.125
Z -.125
X3.5, Z-1.875 FROM PRINT
X3.75, Z-2
X3.75, Z2.575 PT 7
X3.35 SAME
X3.35 Z02.825
X3.75 -2.825
X3.75 Z-3575
X5 Z????
G02/G03, what side of the axis is being cut on
Same questions as we used in the last class for making arcs on a CNC mill.
- What direction is the arc?
- Where’s the end point?
- What’s the distance of start point to center of rotation?
Answers:
- CW or CCW.
- Use I, K incremental values
- Do NOT DOUBLE the I. (I uses radial values.)
Practice Packet:
HAAS H/O
Circular Interpolation Exercise, pg 38
What directions is is: CW = G02
Where is end point?
What is distance from start of arc to center of rotation?
In-class exercises
HAAS worksheet pg 39, 2nd example
First time with no 90 degree turn
.5422 – .293 – .293 = x5.836
N## G03 X 5.422, z-2.5,
Third question: what axis is this in?
In this example, both x, z travel, so I, K need values
Rise over run, negative x
Pic
Pg 40
Practice I, K
Two methods to write for ARCs
We use I and K because
If I make a mistake, the machine will not do the cut
If I use the R-method,
Direction, end point, and Radius
The machine will make the cut. It won’t stop for mistake (conflicting data)
Worksheet, homework
IMTL 153 print 152-2
Milling review: Mill boss on top (boss?)
Tool list
T1 1” carb EM (Boss only) (don’t do 3”) Off part
T2 #5 Center Drill CD
T3 .5 DR (remember deep hole) Part is 6 dia deep
Can’t use G81???
