South Bend Tools
For Machines Mfd. Since 10/21
Model SB1118
-45-
S E R V I C E
Tensioning/Replacing Timing Belt
Items Needed
Qty
Hex Wrenches 4, 5mm .................................... 1 Ea
5.
To adjust timing belt tension, gently press on
feed motor output shaft (see Figure 55), and
tighten cap screws when tension is correct.
Note:
Timing belt is properly tensioned when
there is approximately
1
⁄
4
" deflection when
moderate pressure is applied to them midway
between pulleys, as illustrated in Figure 56.
Gearbox
Pulley
Approximately
1
⁄
4
" Deflection
Motor
Pulley
Figure
Figure 56. Checking timing belt deflection.
. Checking timing belt deflection.
To tension/replace timing belt:
1.
DISCONNECT MACHINE FROM POWER!
2.
Open headstock cover and remove upper
and lower side panels on left-hand side of
machine (see Figure 55).
3.
Loosen (4) cap screws (see Figure 55)
securing feed motor to mounting plate.
4.
If timing belt needs to be replaced, gently lift
feed motor output shaft (see Figure 55) to
release belt tension, roll belt off pulleys, then
replace with new belt.
Figure
Figure 55. Location of timing belt and pulleys.
. Location of timing belt and pulleys.
Motor Pulley &
Motor Pulley &
Output Shaft
Output Shaft
Timing Belt
Timing Belt
Gearbox Pulley
Gearbox Pulley
!
Cap
Cap
Screws
Screws
(1 of 4)
(1 of 4)
