Spring Tension & Replacement

Spring Tension & Replacement for XM2 Labs SLG-20 Retractable Landing Gear

Spring Function

Since the servos on the SLG-20 are only powered when the mechanism is moving, the springs function to lock out the mechanism in the UP and DOWN position when the servo is turned off.

Spring tension and condition should be checked as part of the pre flight checks.

Spring durability and replacement

The SLG-20 uses rubber springs which are quite durable and resistant to vibration. However, over time, they will degrade through load cycles and exposure to UV. It is easy to see when a spring needs replacement as they will develop small cracks on the surface of the rubber and go light in color.

Spare springs are available for purchase and the replacement process is easy. To replace a spring, simply remove the old one from the split ring mounted on the wire rope and fit a new one.

This is an example of a worn spring which is due for replacement - note light color and small cracks in surface

Spring tension

Getting the spring tension right is critical to good operation of the SLG-20.

The spring tension is adjusted by moving the spring holder UP or DOWN the leg to increase or decrease the tension on the spring.

If the spring is not under enough tension, the mechanism may not lock itself correctly and may move when the servo powers off. If the spring is under too much tension, it will put too much load on the servo and the legs may fail to raise of lower.

Setting the correct spring tension

• Raise the legs so they are in the retracted position

• Adjust the spring tension so that when the mechanism is at the full extent of its movement, there is a small amount of tension in the spring.