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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.

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Also, realizing I could be wrong too, in that the lower or down limit switch is maybe the one that needs to be the lighter force to actuate? In an "ideal" world, we want them both to be equal, but if we have to pick and choose, I could have been wrong in my previous post which one was more critical to operation.

The theory is, the cam is dragging on that lower limit switch at the exact moment the solenoid is weakest trying to start pulling in the plunger and lifting and accelerating the platform. The upper limit switch is hit by the cam at about the halfway up point, but by then the system is already moving, the solenoid is in the stronger state of pull just before the upper switch turns off the coil.

So really, drag in the beginning of the cycle is a huge part that determines the voltage required to fully actuate up. Down, we are helped by gravity, but up is kind of the killer state.

Further, the spring and it's adjustment are there to hopefully counteract the effect of gravity pulling the platform down. I noticed this when manually moving mine just now, you can feel the spring and the tension trying to counterbalance the weight of the moving passenger platform. It should be neutral.

Last edited by Vernon Barry

Follow-up:

I replaced the two DICGU micro switches with the Zippy micro switches.  The adjuster is no longer available, but the replacement spring doesn't have as much tension as the original so I attached that to the two screws discarding the original spring.

I also lubricated the plunger with Labelle 106 grease as well as a few other sliding parts.  I lubricated the pivot points with CRC 2-26 light weight oil.

Results:  Works perfectly at 14-16VAC now.

Thanks for all the help.

Regards,

John

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