Centring, Drilling Counterboring and Countersinking, Reaming and Tapping on the Drilling Machines - Course: Techniques for Machining of Material. Instruction Examples for Practical Vocational Training: Instruction example 1.4. Prismatic guideway

Centring, Drilling Counterboring and Countersinking, Reaming and Tapping on the Drilling Machines - Course: Techniques for Machining of Material. Instruction Examples for Practical Vocational Training

		(introduction...)
		Introduction
		Instruction example 1.1. Distance piece
		Instruction example 1.2. Gib
		Instruction example 1.3. Cylinder
		Instruction example 1.4. Prismatic guideway
		Instruction example 1.5. Stop

Instruction example 1.4. Prismatic guideway

This instruction example describes drilling, countersinking and reaming of prismatic workpieces which have tapered bores. Centring or punch marking as well as mounting holes are presupposed. The workpieces are premachined in their outer contours.

Figure

Material

15 Cr 3 (0.15 % carbon, 0.6 % chromium)

Dimensions

120 × 60 × 20 (premachined)

Tools

Twist drill of Ø 8, taper reamer (1 : 50)

Measuring and testing means

Vernier caliper, taper pin of Ø 8 (1 : 0)

Auxiliaries

Machine vice, drill chuck, taper sleeves, drill drift, parallels, coolant and lubricant

Required previous knowledge

Reading of drawings, measuring and testing, kinds and applications of tools, clamping and auxiliary equipment, kinds and shapes of tapers

Explanations to the working drawing

(K = 1:50): taper per inch, on 50 mm of length 1 mm of taper

Sequence of operations	Remarks
1. Measure rough dimensions.	In case of undersize reject workpiece.
2. Clamp workpiece.	Kind of clamping: loose vice clamping, insert parallels (be careful not to drill them). Clamp for size 60 mm.
3. Clamp tool.	Insert drill chuck, use taper sleeves.
4. Align.
5. Drill first through hole of Ø 8 mm.	Spot-drill and check for centre, finish through hole as preparation for reaming, use coolant.
6. Align.
7. Drill second through hole of Ø 8 mm.	Finish hole according to working step 5.
8. Clamp tool.	Insert reamer into drill chuck or use taper sleeves in case of taper shank.
9. Align.
10. Ream first taper hole.	Finish taper hole, use coolant. Feed by hand and uniformly.
11. Align.
12. Ream second taper hole.	Finish second taper hole according to working step 10.
13. Make dimensional and visual check inspection.	Deburr the holes with suitable means. In case of series production finish the hole of Ø 8 mm first and then ream.

Prismatic guideway