Jet JTM-1, Operating Instructions And Parts Manual

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11.7 Draw bar operation; changing
tooling
The drawbar has 7/16”-20 right hand threads and
should be tightened with normal pressure using
provided wrench. To remove a tool:
1. Lock spindle by turning spindle brake (C,
Figure 8) left or right.
2. Use provided wrench to loosen draw bar two
or three turns (counterclockwise).
3. If collect does not open immediately, tap the
top of draw bar with a soft-faced hammer to
loosen collet from taper.
4. Remove tool from collet.
5. Insert new tool into collet.
6. Tighten draw bar firmly using provided wrench.
The tool is now ready for use.
7. Release spindle brake.
12.0 Adjustments
12.1 Head movement: left and right
Make sure machine base is
secured to floor before repositioning mill head.
The center of gravity can shift enough to cause
machine to tip over, resulting in serious injury
to operator and damage to machine.
1. Loosen four large hex nuts (A, Figure 9) that
secure mill head to ram adapter. One-quarter
(1/4) turn should be sufficient to allow head to
move.
NOTE : For angles greater than 10 degrees,
use your free hand to support mill head,
relieving weight off the brass worm gears.
Doing so will lengthen life of worm gears.
2. Turn worm nut (B, Figure 9) to tilt head left or
right as required. Use scale on ram adapter to
establish angle.
Note: The scales on ram adapter and for head
rotation are guides only. Close tolerance work
will require use of a dial indicator to make sure
head is 90° to table in X and Y axes. Please
note the table is fitted to be slightly higher in
front, usually about 0.0005”.
Be sure to apply torque in
two steps using a crossing pattern. Failure
to do so could distort the face of the ram
adapter.
3. Tighten the four hex nuts. Tighten in two steps
using a calibrated torque wrench. Use a
crossing pattern to tighten the nuts. Tighten
initially to 25 foot-pounds.
Figure 9
4. Before applying final torque, check to make
sure mill head is perpendicular to worktable.
5. Set up a dial indicator in a collet (see Figure 9)
and secure using draw bar.
6. Put spindle drive in neutral.
7. Set the dial indicator plunger on the worktable.
Zero indicator.
8. Rotate spindle 180 degrees (when rotating,
raise dial indicator plunger by hand to prevent
it from dropping into table T-slots).
9. Read dial indicator – it should read zero. If not,
loosen the four hex nuts and reposition mill
head.
10. Recheck perpendicularity using dial indicator.
Repeat the above procedure until dial indicator
reads zero in both positions.
Be sure to apply torque in
two steps using a crossing pattern. Failure
to do so could distort the face of the ram
adapter.
11. Tighten the four hex nuts. Tighten in two steps
using a calibrated torque wrench. Use a
crossing pattern to tighten the nuts. Tighten
initially to 25 foot-pounds, then tighten to final
torque of 50 foot-pounds. NOTE: Do not
overtighten, as it may cause binding of quill.