Again, here is how it works. When you click activate up and the platform is down, the microswitch for that coil is in the normally closed state. So the current goes to the coil and begins pulling the plunger slug. Magnetic force is a combination of distance- how close the metal slug is to the coil and the current through the coil- proportional to source voltage. Because when it starts, the motor or solenoid is in it's LEAST strong state of pull, and then as the platform begins to rise up and accelerate the strength pulling increases. However, the switch is ALSO being actuated by the cam somewhere in this midway point. The switch friction slightly slows down the rising platform and since the coil cuts off before the end limit, we are now coasting on any inertia built up in the platform. Also, the cam and switch friction help to form a kind of "over center" detent to keep the platform locked in the up position.
The system is that sensitive between the weight of the platform moving, the springs, gravity, and the friction and detent force provided by the switch and cam determines what voltage is strong enough to reliably lift and push this platform over center to the up position.
You might also lube the moving parts like the cams with very light grease.
