STEMME S12, Руководство по обслуживанию

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DOCUMENT NUMBER:
L500-912.820 ISSUE JUL 20, 2016
AMENDMENT: 00
DATE: --
CHAPTER- PAGE 7-34
MAINTENANCE MANUAL STEMME S12
7.4.10.6 SPRING TENSION OF THE PROPELLER FOLDING MECHANISM
• Check the spring pre-load for each blade: after the propeller has been installed, turn it
until the leading edge of the (folded) lower propeller blade is in a horizontal position. The
static holding force (not the lift-off force) on the rubber catch in this position must be
1.7 N ± 0.1 N (approx. 30 mm / 1.18 in away from the tip of the propeller blade measured
with a spring balance or weight). Even after swinging out slightly it must return to the fully
folded position of its own accord. Move the propeller to the appropriate position before
repeating the measurement on the other propeller blade.
• Removal of the propeller blades (to renew the lubrication of the blade bearings, installation
in the reverse order):
NOTICE
Completely remove and reinstall the first blade before removing the second blade.
1. Unscrew the union nut of the hollow axle using a flat, size 30 nut wrench (approx. 4.5 mm
/ 0.18 in thick) while holding the hollow axle fast with a flat, size 22 nut wrench (approx.
4.5 mm / 0.18 in). Do NOT unscrew the castellated nut.
2. Twist the hollow axle (in an anti-clockwise direction) until the spring is no longer pre-loaded
(approx. 1½ turns) and press it out. Make sure the blade does not drop off when doing so
and then remove the blade from the fork (Warning: 2 thrust plates).
3. If necessary, dismantle the hollow axle (now undoing the castellated nut), clean, lubricate
and reassemble it.
4. Push out the inner ring of the blade bearing, remove and clean the needles, inspect them
for any damage, insert the 34 original needles with special grease in the outer ring, then
push the inner ring back in.
CAUTION
Under no circumstances must the needles and the inner rings of the two blade bearings be mixed
up. Should this nevertheless occur, send the entire (dismantled) propeller to the manufacturer
immediately. The needles and inner rings generally have different tolerances to cater for bearing
clearance.
• Setting the spring pre-load: the spring pre-load is generated by twisting the spiral torsion
spring (23), i.e. by twisting the pre-mounted hollow axle (3) against the fork (4).
• Renew the safety plate beforehand: remove the M4 locking screw for the safety plate
(beneath the union nut of the hollow axle), undo the union nut (see above: Dismantling
and …), renew the safety plate; screw the union nut tight again.
• Twist the hollow axle to achieve the required spring load. Drill a hole in the new safety
plate (diameter 4.3 mm / 0.17 in) so that the locking screw can be mounted in the required
position of the hollow axle (secure the locking screw by screwing it tight with a self-locking
nut and locking compound). Secure the union nut through the safety plate.
• Check the function (see above).