6.1 Introduction
Tim A. Bacon
Knowing how to create a reliable work plan is essential to success in the machining field. Planning requires critical thinking and problem-solving skills which are highly sought-after machinist traits. In fact, the US Department of Labor, on their O*NET OnLine site (2024), ranks critical thinking as the second most important worker-required skill.
A job plan is a written sequence of general steps to take when making a part. Writing the plan down forces the machinist to think through the complete process before starting. The best way to learn about job planning is to go through the process, especially when you have a part to make. This chapter will look at building a bench block to illustrate the process of making a job plan. As you read, make note of how decisions are made and documented. The written plan must be easy to follow when making the part. With the information provided in this chapter, you will be able to replicate the process and write your own job plan.
| Project Planning For | |||||
| Sequence | Feature | Holding | Machine | Tooling | Notes |
|---|---|---|---|---|---|
| 1 | Grind | Magnetic chuck | Surface grinder | Minimal material removal | |
| 2 | Spot drill | Vice with parallels | Vertical mill | Add step to square up stock | |
| 3 | Drill | Vice with parallels | Vertical mill | ||
| 4 | Bore | Vice with parallels | Vertical mill | Adjustable boring head | |
| 5 | Groove | Vice with parallels | Vertical mill | Flat end mill | Tilt head to 45 deg |
| 6 | Counter bore | Vice with parallels | Vertical mill | Flat end mill | Rotary table |
| 7 | Profile | Through holes with fixture in three jaw | Vertical mill | Flat end mill | Rotary table |
| 8 | Knurl | Through holes with fixture in three jaw | Lathe | Pinch knurl tool | |
| 9 | Turn | Through holes with fixture in three jaw | Lathe | Turning tool | |
| 1.5 | Square up stock | Vice | Vertical mill | Face mill | |
| option | Counter bore | Three jaw chuck or form jaws | Lathe | Boring bar | |
| option | Profile | Through holes with fixture in three jaw | Lathe | Turning tool | |
Note: A table showing project planning for a bench block.
A bench block is a tool that is used when working with hand tools such as drills and taps. It will assist in keeping the drill and tap perpendicular to the part that is being worked on. A machinist can also use it to hold small round cylindrical parts when working on them. This use is a type of workholding. Bench blocks are useful tools, and every machinist should have one. You can buy them, but making one helps students build necessary skills, and doing so is a common assignment because of the many skills needed to build it.
The Role of Job Planning in Machining
Job planning is a best practice because it saves time and effort when making a part. It is also an expectation in the workplace because it saves the employer time and money.
One way job planning saves an employer money is by reducing the material used to make a