150
MACT 150 Introduction to CNC and EDM
MACT 150 CNC Mill Final Project

CNC Mill Final Project

Use this page to review the final project requirements, open the MACT Editor, check the required tools, and confirm the grading standards before machining.

Open MACT Editor in New Tab

MACT Editor

Use the MACT Editor to write, review, and test your CNC program before running it on the machine. This is where you should check motion, verify program structure, and catch avoidable mistakes.

Launch MACT Editor

Check your motion

Look for rapid moves, unsafe Z motion, missing clearance moves, incorrect arcs, and toolpaths that do not match the print.

Check your setup blocks

Confirm the program has safe startup code, correct work offset, tool length offset, spindle speed, feed rate, and coolant commands.

Revise before cutting

Your first file is probably not the final file. Use the editor to revise the program before loading it at the machine.

Before machining: backplot, dry-run, single-block, and verify your offsets.

Final Project

This project is manually programmed. Do not use Mastercam or other CAD/CAM. You will square the stock, machine the contour, machine the pockets, engrave initials, create the bolt hole pattern, inspect the part, and upload the final revised .nc file.

NO MASTERCAM OR OTHER CAD/CAM. This is a manual CNC programming project.

Project Overview

The finished project includes an outside profile, rectangular pocket, circular pocket, engraved initials, and a tapped bolt hole pattern.

Manual CNC Programming Mill Project Inspection Required Final .NC Upload
Project Stock Rough X 4.625, Y 3.375, larger than Z .75
Square Material to Finished Size X 4.5, Y 3.175, Z .73
Click to enlarge: Isometric View with Top Dimensions
Click to enlarge: Top Dimensions

Final Submission

After completing the project and completing the inspection guide, once canvas has returned, upload the final and likely revised .nc file used to machine your part.

Step-by-Step Process

Follow the project as a sequence of planned operations. Do not treat this as one big toolpath. Break it down, check each section, and verify each depth.

  1. Layout and rough cut stock.
    Use the bandsaw and leave the stock approximately .050 to .100 oversized.
  2. Square the material to final size.
    Use the manual mill. This is graded for tolerance and squareness.
  3. Machine the outside contour.
    Use a ½ inch flat end mill. Machine the outside contour in two Z passes: first pass .125 deep, second pass .250 deep.
  4. Machine both pockets.
    Use a ¼ inch flat end mill. Machine the pockets in two Z passes: .125 deep and .250 deep. The rectangular pocket is X 1.0 by Y .875. The circular pocket is 1.0 diameter.
  5. Engrave your initials.
    Use a ⅛ inch ball end mill. Engrave .008 deep within a 1 inch by .875 inch box. Include the required “Machine Technology San Diego City College” program text.
  6. Machine the bolt hole pattern.
    First hole starts at 0 degrees on a 1.4 inch diameter bolt circle. Center drill, drill, and HAND tap ¼-20 holes.
Click to enlarge: 3D Render of Final Project
Click to enlarge: Contour and Pocket Dimensions
Click to enlarge: Bolt Hole Pattern Dimensions
Each operation should have a clear purpose, correct tool, correct depth, and safe entry and exit motion.

Tools & Specs

Use the correct tool for each operation. Your tool numbers may change depending on the machine setup, but your program should clearly match each tool to its operation.

Required Tools

  • Tool 1: ½ inch diameter flat end mill, 2 flute
  • Tool 2: #4 center drill
  • Tool 3: #7 drill, .201 diameter, 118° drill point angle
  • Tool 4: ¼ inch diameter flat end mill, 2 flute
  • Tool 5: ⅛ inch diameter ball end mill, 2 flute

Additional Informaion

  1. Cutting Speed [End Mill - 200 | Drill - 100]
  2. Chipload caculated a Cutter Diameter X 0.010
  3. (CS X 12)/(Pi x Diameter)
  4. RPM X Number of Teeth X CPT
Outside Contour Two Z passes: .125 deep and .250 deep using ½ inch flat end mill.
Rectangular Pocket X 1.0 by Y .875. Machine in two Z passes using ¼ inch flat end mill.
Circular Pocket 1.0 diameter. Machine in two Z passes using ¼ inch flat end mill.
Initials Engrave .008 deep inside a 1 inch by .875 inch area using ⅛ inch ball end mill.
Bolt Hole Pattern 1.4 inch diameter bolt circle. First hole at 0 degrees. Center drill, drill, and tap ¼-20.
Keep tool numbers, H offsets, D offsets, spindle speeds, feed rates, and work offset calls clear and consistent.

Grading

The project is graded on accuracy, squareness, setup quality, safe machining practice, and whether each required feature is completed correctly.

± .002 A-level work
± .003 B-level work
± .004 C-level work
± .005 D-level work
Outside Tolerance 0% for that detail

Broken Tool

Each broken tool equals one grade reduction.

Scrap Part

Each scrap part, except the setup part, equals one grade reduction.

Machine Crash

A machine crash equals one grade reduction.

How to protect your grade

  • Check your math before programming.
  • Use the MACT Editor before machining.
  • Backplot and verify the NC file.
  • Use safe Z moves and proper clearance planes.
  • Check offsets before cycle start.
  • Inspect the part before calling it finished.
  • Upload the final revised .nc file, not the rough draft.