CM-ET Lodestar - Manual (Page 14)

LOAD CHAIN
Chain should feed smoothly into and away from the hoist or
hook block. If chain binds, jumps or is noisy, first clean and
lubricate it (see below). If trouble persists, inspect chain and
mating parts for wear, distortion or other damage.
Chain Inspection
First Clean chain with a non-caustic/non-acid type solvent and
make a link by link inspection for nicks, gouges, twisted links,
weld splatter, corrosion pits, striations (minute parallel lines),
cracks in weld areas, wear and stretching. Chain with any one
of these defects must be replaced.
Slack the portion if the chain that normally passes over the lift-
wheel. Examine the interlink area for the point of maximum
wear (polishing, see Figure 15). Measure and record the stock
diameter at this point of the link. Then measure stock diameter
in the same area on a link that does not pass over the liftwheel
(use the link adjacent to the loose end link for this purpose).
compare these two measurements. If the stock diameter of the
worn link is 0.010 inches (0.254 mm), or more, less than the
stock diameter of the unworn link, the chain must be replace.
On double reeved units, repeat this examination of the chain
that passes through the hook block.
Also check chain for stretch using a vernier caliper as shown
in Figure 16. Select an unused, unstretched section of chain
(usually at the lose end) and measure and record the length
over 11 chain links (pitches). Measure and record the same
length on a worn section of the chain. Obtain the amount of
stretch and wear by subtracting the measurement of the worn
section. If the result (amount of stretch and wear) is greater
than 0.145 inch (3.7mm), the chain must be replaced.
Use only a “Knife-edge” caliper to eliminate possibility of false
reading by not measuring full pitch length.
Note that worn chain can be an indication of worn hoist com-
ponents. For this reason, the hoist’s chain guide, hook block
and liftwheel should be examined for wear and replaced as
necessary when replacing worn chain.
Also, these chains are specially heat treated and hardened
and should never be repaired.
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IMPORTANT: Do not use replaced chain for other pur-
poses such as lifting or pulling. Load chain may break sud-
denly without visual deformation. For this reason, cut replaced
chain into short lengths to prevent use after disposal.
10
Figure 14. Hook Inspection
MEASURE
OPENING
LATCH TYPE HOOK
(Upper and Lower)
TO MEASURE OPENING,
DEPRESS LATCH AGAINST
HOOK BODY AS SHOWN.
LATCHLOCK® TYPE HOOK
(UPPER AND LOWER)
“A”
“B” Max.
Models
Replace Hooks
When Opening
is Greater
Than
B, C AND F 1 3/16 (30.2mm)
J, L, AND LL 1 5/16 (33.3mm)
R AND RR
1 1/2 (38.1mm)
Models
Replace Hook
When Opening
or Seat are:
B, C, F, J, L, AND LL
“A” Max “B” Max
1 31/64 in.
(37.7mm)
2 1/32 in.
(51.6mm)
R AND RR 1 59/64 in.
(48.8mm)
27/32 in.
(21.4mm)
Figure 15. Chain Wear Areas
W WA AR RN NIIN NG G
Use of commerical or other manufactures’ chain and parts
to repair Lodestar Hoists may cause load loss.
T TO O A AV VO OIID D IIN NJ JU UR RY Y::
Use only factory supplied replacement load chain and parts.
Chain and parts may look alike, but factory original chain
and parts are made of specific materials or processed to
achieve specific properties. See Figure 17.
V
!!
Figure 17. Chain Embossing
Figure 16. Chain Inspection