Cutting by Milling - Course: Techniques for Machining of Material. Instruction Examples for Practical Vocational Training: Instruction example 6.3.: Fixing bush

Cutting by Milling - Course: Techniques for Machining of Material. Instruction Examples for Practical Vocational Training

		(introduction...)
		Introduction
		Instruction example 6.1.: Backing material
		Instruction example 6.2.: Measuring point
		Instruction example 6.3.: Fixing bush
		Instruction example 6.4.: Segment

Instruction example 6.3.: Fixing bush

A bush-shaped workpiece made of grey cast iron has to be separated (slotted) with a metal slitting saw blade half way of its bore.

Material

GGL 25 (grey cast iron with laminated graphite, tensile strength 250 MPa, compressive strength 1000 MPa)

Figure

Dimensions

Ø 40 x Ø 80 x 120 mm

Milling machine

Horizontal milling machine

Tools

Metal slitting saw blade (Ø 125 - 150 x 2.5 mm), long cutter arbor, machine vice, clamping intake, chucking screws, keys

Measuring and testing means

Vernier caliper, steel square

Auxiliaries

Stop rack, chip brush, hand broom, cleaning rag, T-slot cleaner, tongues for the machine vice

Required previous knowledge

To read a drawing, to measure and to test, to set-up and to operate horizontal milling machines

Sequence of operations	Remarks

1. Batch-quantity and visual control of the supplied workpieces	Comparison with the specifications of the work accompanying data sheets

2. Functional test and lubrication of the milling machine	Lubrication and oil-level check according to the lubrication schedule

3. Fixing and adjusting the machine vice (along the machine table)	The adjustment and localization is done by means of the tongues and steel squares

4. Fastening the cutter arbor (long) and fixing the metal slitting saw blade	Do not forget the feather key!

5. Setting-up the milling protective system	Pay attention to the space between the milling protective device and the upper edge of the workpiece!

6. Clamping in and adjusting the workpiece according to the marking (separating slot)	The adjustment should be carried out with a steel square on a slightly fastened workpiece. A side stop secures the concentricity of the separating slot.

7. Fixing the cutting values

8. Position the milling table into the working position	Place the metal slitting saw blade manually on the marking of the separation slot.

9. Cutting by milling of the fixing bush (semi-sided cutting)	Observation of the metal slitting saw blade during cutting by milling on "standstill".

10. Declamp and clean the work-piece	The clamping out of the workpiece should be carried out before the return stroke of the milling table.

11. Visual control of the work-piece	Control if the separating slot is situated at the marked point (marking).

12. Continuation of cutting by milling until all fixing bushes are slotted	With a large number of pieces the metal slitting saw blade should be changed in time.

Fixing bush