Chart 1-3 Process Planning Quality Control Check Sheet
| Date | Checked By | ||
| Part Name | Part Number | ||
| Sheet ___ of ___ | |||
| Blueprint Dimentsion | Tolerance | Actual Dimension | Comments |
Figure 1-2 Machining Center Process Planning
In the example in Figure 1-2, it will be necessary to machine the part from a solid blank of Aluminum that is pre-machined to 4.25 square and is 1.25 thick. The top surface must have .125 inch of material removed as well. Dimensional tolerances are as follows: .X = plus or minus .015 inch, .XX = plus or minus .010 inch, .XXX = plus or minus .005 inch, and angular tolerance is plus or minus .5 degree. Please use the copies of the Process Planning sheets and develop a plan to machine the part to dimensional requirements. Make your tool selections from the CNC Machining Center Tool List found in Unit 4, CNC Machining Center Programming.
Feeds and Speeds
Charts 1-4 and 1-5 are supplied for use in answering the exercise problems presented here. The Surface Feet per Minute (SFPM) and Feed in inches per revolution (in/rev) values represented here are given in ranges. Note that the values starting at the low end of the range are intended as a minimum starting point for calculations; those at the high end are a maximum recommended SFPM and Feed. Final values used for machining may differ based on many factors. As you answer the problems, use values that are within the ranges given. Refer to Programming of CNC Machines (Part 1, CNC Basics, Metal Cutting Factors) for detailed information regarding Feed and Speed calculations. A more comprehensive source for machining data is the Machinery’s Handbook; other valuable sources for machining data are in the tool and insert catalogs and online applications supplied by cutting tool manufacturers.
Chart 1-4 Feeds and Speeds for Turning
| Tool Material | ||
| Material | High Speed Steel | Carbide |
| Carbon Steel Feed in/rev | 30–60.006–.012 | 200–1300.008–.036 |
| Alloy Steel Feed in/rev | 30–120.006–.012 | 125–1000.008–.036 |
| Stainless Steel Feed in/rev | 25–110.006–.012 | 80–945.007–.036 |
| Aluminum Feed in/rev |
500–800.006–.012
|
