Figure 8-13.--Line shaft bearing that has had the "cheeks" or oil reservoir grooves cut into it.
direction selection lever position remains unchanged.
as many as 23 different threads, both standard and
Allow the machine to run in this direction until the
cutting tool has returned to its starting point. Advance
To cut threads with these machines, use a system
the cutter to cut the thread a little deeper, set the
spindle motor to run in forward, then make another
leads. Secure a single-point tool in a suitable
cutting pass. Follow this procedure until the thread is
toolholder and mount the toolholder in the spindle of
completed. A boring bar with a micro-adjustable tool
the machine. While you cut threads, keep the spindle
bit or a small precision head is ideal for this operation.
locked in place. The saddle, carrying the workpiece,
It allows fast, easy adjustment of the tool depth and
advances at a rate determined by the change gear
accuracy and control of the depth setting.
combination, Feeding, in conjunction with the
spindle rotation in the low back gear range, produces
When you set up to cut threads, remove the thread
lead access covers and set up the correct gear train
combination as prescribed by the manufacturer's
technical manual. After you have set up the gear
Cut the thread a little at a time in successive
train, tighten the nuts on the arm clamp to lock the
passes. The thread profile depends on how the cutting
sliding arm. Be sure to replace the retaining washers
tool is ground. When you have completed the first
on all the studs and lock them with the screws
pass, back the cutting tool off a few thousandths of an
p r o v i d e d with the machine. Refer to the
inch to avoid touching the workpiece on the return
manufacturer's technical manual for the machine you
movement. Then, reverse the spindle driving motor.
are using for the correct gear arrangement.
This causes the saddle direction to reverse while the