Page 21 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

Fig 4

File and adjust the radius gradually according to the radius gauge.
The right radius is the one that matches correctly with the gauge. (Fig 5)
After using the radius gauges, wipe them, clean with a clean cloth and apply a light film of oil before storing.

Fig 5

Reaming a hole by a hand reamer on the lathe

Objectives:At the end of this exercise you shall be able to
• set the machine for hand reaming
• set the reamer on a lathe
• ream a hole accurately with a hand reamer.

The procedure sequence of hand reaming on a lathe is as follows.
Check the drilled hole to ensure that it has the required reaming allowance.
Choose the correct type and size of reamer.
Remove the tool-holder and tool post.
Fix up the tap wrench to the square end of the reamer. The tap wrench must be short enough to clear the lathe
bed.
Move the tailstock back so that there is sufficient space for the reamer between the dead centre and the workpiece.
Place the reamer into the pre-drilled hole slightly with the shank supported by the tailstock dead centre. (Fig 1)
Apply cutting fluid to the reamer during reaming.

The job should not be rotated by power.
Now gently rotate the reamer clockwise with” the wrench as you turn the tailstock hand wheel to support and
advance the reamer into the hole. (Fig 1)

An adjustable wrench can also be used to rotate the reamer instead of the tap wrench.
When the hole is fully reamed, continue to rotate the reamer clockwise as you- pull it out of the hole.

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CITS : C G & M - Fitter - Exercise 59