Hi,
OPs diagram.
Why do you need the long wires, you are using a wifi connection, why not place the controller at the "rolling metal object"?
Have you placed say a 100uF and 0.1uF capacitors across the supply to gnd at the "rolling metal object" end?
How do the wires contact the "rolling metal object"?
If you have the project on the bench and it works okay, is that with the 100ft of cable still in circuit?
Thanks.. Tom... 