Taking apart and putting back together asymmetry

[chook]

Last week the rise and fall on my table saw jammed tight. It was suggested that the problem was sawdust stuck in the gears and so it was. A bit of a clean up and some dry lube and it woks fine. In the process I came up against two fundamental laws of the universe.

Firstly taking a mechanical object apart and putting it back together are not symmetrical processes. It took almost no time to take the saw apart and most of an afternoon to get it back together, adjusted and working.

Secondly when I took it apart I put all the screws into a container. When I put it back together I found that I had used all the screws and nuts. This is worrying. There should be a screw or a washer left over. There is always something left over.

But at least the saw works.

[Robson Valley]

If you take it apart 10 times, there should be enough left over parts to build another one.
How did I rebuild a big tripod and have 4 leg parts left over?

Years back, 2 roomies were machinists. During the length of the adverts in an evening's television, they stripped and cleaned the pump system in the clothes washer. Everytime they came across a part which looked symmetrical, they carved a scratch where it met the next part
to index the reassembly.

[chook]

If you take it apart 10 times, there should be enough left over parts to build another one.
How did I rebuild a big tripod and have 4 leg parts left over?

Years back, 2 roomies were machinists. During the length of the adverts in an evening's television, they stripped and cleaned the pump system in the clothes washer. Everytime they came across a part which looked symmetrical, they carved a scratch where it met the next part
to index the reassembly.

I never thought of that.