2 wires, a ball bearing and a buzzer

[PJSprog]

Actually, it doesn't. He is using the second transverse WIRE as his point. The other end can be off any amount, he brings the wire back to plane against the other wire. The wire will be 'flat' given enough tension between its points. And if the wire is essentially 'level' or a close approximation, the table will also be level.

The most important thing is that the table is flat compared to itself. Not compared to the poured concrete floor.

If the bench he's moving that transverse ware across isn't flat, then it will affect the results. If it is, say, higher at one end, or has a bump in the middle, that will throw off the level of the wire as he's moving it along that surface.

I'm not questioning the wire, but rather the surface the wire and assembly are mounted to.

 

[jrdepew]

If the bench he's moving that transverse ware across isn't flat, then it will affect the results. If it is, say, higher at one end, or has a bump in the middle, that will throw off the level of the wire as he's moving it along that surface.

I'm not questioning the wire, but rather the surface the wire and assembly are mounted to.

He is adjusting for the flatness of the table by adjusting the wire up and down. There is another wire across the 2x2" steel square tube that is under high tension, ensuring it is flat. He adjusts the wire that he is traversing across the table to just barely touch this wire, establishing a flat plane.

See this image from the video:


-Joe