Module 4. Basic G - Code programming
Duration: 50 hours
EQF: 4
ECVET: 1,8 C
Activity 1 - Lesson - G00, G01, M03, M04, G90, G91
Step 1: Present students with the machine axes and the need for a standard cartesian coordinate system. Introduce students to G90 and G91.
Step 2: Present to students the difference between G and M codes. Common G and M codes including G00, G01, M03 and M04.
Examples:
1. A facing operation.
2. machining a workpiece with drilling operations only.
3. machining a workpiece with straight slots.
Activity 2 - Lesson - G20, G21, G70, G71, M05, M06
Step 1: Present students with a brief summary of Activity 1
Step 2: Present students with more G codes - G20, G21, G70, G71
Step 3: Present to students modal and non-modal letter addresses
Step 4: Present students M05 and M06 the program structure - Setup phase, material cutting phase, and shut down phase. Show them an example of a short G-Code program and split it into its different phases.
Activity 3 - Workshop session - Datum setting and auto mode machining. (2, 3 students per CNC machine, 100% supervision)
Step 1: Show the students how to probe the workpiece with an edge finder and set the workpiece datum on the CNC machine.
Step 2: Ask students to write a short G - code program for a given workpiece (parameters are all given) and machine the part in automatic mode.
Step 3: Ask students to measure the part and accept or reject it. In case the part is not acceptable, students are to think and reflect to find out any possible reasons why.
Activity 4 - Lesson - Circular interpolation
Step 1: Present students with a brief summary of all G codes covered.
Step 2: Present students with the G02 and G03
Step 3: Assign students an exercise in which they have to write the G-Code program of a part with circular features.
Activity 5 - Lesson - Cutter compensation
Step 1: Present students with a brief summary of all G codes covered.
Step 2: Present students with the Cutter diameter compensation and Cutter length compensation
Step 3: Present students with the G04
Step 4: Show students a programming example
Activity 6 - Lesson - Canned cycles
Step 1: Present students with a brief summary of all G codes covered.
Step 2: Present students the Canned cycles - G80, G81, G83
Step 3: Show students a programming example using canned cycles
Activity 7 - Lesson - Subroutines
Step 1: Present students with a brief summary of all G codes covered.
Step 2: Present to students what are subroutines and how to use them.
Step 3: Show students a programming example using subroutines.
Tools and materials needed:
a classroom equipped with a computer, audiovisual system (big screen, or projector)
whiteboard
a workshop equipped with a surface plate, electronic calipers and micrometres
some engineering components together with their engineering drawings
Key Learning Outcome(s)
S3 To properly operate basic tasks on a CNC machine.
Assessment methodology: An individual assessment is to be carried out in a workshop where the learner is given an operational plan, a tools list, and a setup sheet to manufacture the part autonomously and ascertain its quality.