must not be used, since they will not withstand the extreme
contact pressures. If grease of the above specification, or an
equivalent, is not available, be sure to use an
extreme-pressure, low-temperature grease from a reliable
commercial source.
20. TROUBLE SHOOTING.
21. Principal troubles that might be encountered, together
with their possible causes and remedies, are given in
Table II.
Trouble
TABLE II. TROUBLE SHOOTING
Remedy
Probable Cause
TUBE WRINKLES ON INNER
RADIUS OF BEND
RIDGES ARE FORMED ON
TUBE AT BEND
TUBING MARRED AT BEND
DRIVE SHAFT FAILS TO RO-
TATE WHEN RATCHET IS
OPERATED
TUBE BENDER BINDS OR
LOCKS
Tubing 0. D. is undersize or out
of tolerance specified in Table I,
and therefore does not properly
fit the grooves in the form block
and shoe.
Feed screw not tightened suffi-
ciently to force edges of form
block and shoe together.
Incorrect size of form block and
shoe being used
Damaged form block and/or shoe
Shear pin sheared in drive end
permitting it to slip on shaft
Damaged gears
Worn gears
Damaged ball bearings
Use proper size tubing.
Tighten feed screw.
Change to correct size of form
block and shoe.
Replace damaged components.
Install a new shear pin.
(38, figure 12. )
Disassemble the tube bender
proper and replace damaged
parts.
Disassemble the tube bender
proper and replace damaged
parts.
Replace ball bearings.
22. DISASSEMBLY. (See figure 12.)
NOTE
a. Remove the cap screw (21) and lock washer (22) to free
the screw post (20) from the upper half housing (28). Slide
the form shoe slide block (19) off the slide block support
(24). If removal of the feed screw (18) from the form shoe
slide block (19) is required, drive out the spring pins (17)
with a long point punch to release the feed screw (18).
If the tube bender proper is operating normally, it is
not necessary to disassemble it at regular calendar
overhaul periods. The only time overhaul
operations are required is when internal trouble is
suspected, at which time the two housing sections
should be separated, all parts cleaned and
inspected, damaged parts replaced and the
housing packed with fresh lubricant.
b. If the slide block support (24) is worn or damaged,
remove the two screws (25) to free the slide block support
(24) from the upper half housing (28).
c. Do not remove the name plate (26) unless it is broken,
or the data thereon is illegible. If removal is required,
remove the two drive screws (27).
d. Remove all socket head screws (29) and lock washers
(30) from the lower half housing (44). It may
be necessary to tap along the parting edges of the upper
and lower half housings (28 and 44) to separate them. Use
the sharp end of a screwdriver blade to pry the housings
apart, if necessary, while exercising care to avoid damaging
the mating surfaces of the two housing valves.
e. After the upper and lower half housings (28 and 44) are
separated, most assemblies can be lifted out of their
respective locations. It may be necessary to use a wood
dowel as a drift to tap the bearings out of their respective
recesses.
f. To remove the spacer (40), drive out the pin (38) with a
long point punch. Make certain the counter-shaft drive end (37)
is properly supported when driving out the (shear) pin (38).
g. Slide the worm gear (35) off the shaft (41).
h. Further disassembly will consist of separating individual
parts that normally would not require removal. The location
of each of these parts is shown in figure 12, and removal or
installation should be obvious since all parts are exploded
out from their proper locations.
23. INSPECTION.
24. The following table provides basic inspection
procedures for all parts of the tube bender assembly. These
checks are to be considered as basic, however, if other
damage not covered in the table is obvious such parts
should be replaced.
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