Nelson NS20A - Disassembly of Gun

NS20A & NS20N Heavy Duty Gun Page 11 Revision 1.20 2/19/08
MAINTENANCE INSTRUCTIONS
If the gun motion becomes sluggish or erratic the gun should be disassembled, cleaned, and lubricated.
Disassembly of Gun
A. Step By Step Gun Disassembly - Refer to
exploded view
1. Loosen leg set screws (39), remove foot and
leg assembly, and unscrew chuck adaptor
(31).
2. Remove cable (26) from threaded hex shaft
adaptor (15), unscrew shaft extension (13a)
from lifting rod assembly (13), and remove
dust seal bellows (4).
3. Unscrew front cover nuts (17), remove front
cover (2), plunge dampener assembly (5),
and balance of lifting rod assembly (13) as a
unit.
4. Unscrew free travel adjustment sleeve (10),
extend the piston rod of the plunge
dampener assembly (5), disengage the spool
shaped dampener rod end from hook of
lifting rod assembly (13) and remove the
plunge dampener assembly thru the front
cover (2).
5. Remove the main spring (7) and lifting
module assembly (18) from the gun body
(1).
6. Remove screw (35) and rear cover (3).
Loosen setscrew (38) and unscrew
adjustable core (9). Do not unscrew, loosen
or remove rear coil yoke (14) or gun coil
(6).
7. Disassembly of the lifting module assembly
(18) is not routinely required. If further
disassembly is necessary, consult Figure 8.
In order to disassemble the lifting module,
the internal retaining ring (18f) must be
removed from the lifting module housing
(18a). When doing this, maintain thumb
pressure on the lifting mechanism stop
(18e) to resist internal spring pressure and
then release retaining ring (18f). Slowly
release thumb pressure and note position of
the lifting mechanism stop (18e), lifting
ring (18d), lifting hook and movable core
assembly (18c) and ring-core spring (18b)
as they are removed from the lift
mechanism housing (18a).
Figure 8: Explosion diagram of Lifting Module
Item # Description Part Number
18a Lifting Module Housing 751-535-024
18b Ring Core Spring 526-001-192
18c Lifting Hook & Movable Core
Assembly
751-535-026
18d Lifting Ring 751-535-022
18e Lifting Module Stop 751-535-023
18f Internal Retaining Ring 717-881-003