Originally Posted by
handlewanker
Hi, when you fit spark plugs the force is indicated by the compression of the washer........have you tried making a compression washer calibrated to give some force or other?
Going to the press tool industry, when tremendous spring pressure is required we/they use a type of very incompressible rubber, red in colour that is almost plastic in consistency.....it gives tremendous spring force over a very short distance.
I would suggest that you made a 3mm thick steel cupped washer and made a rubber washer with this material.....if the washer was made in the form of a cup and the rubber insert was inside it with another steel washer on top, provided you had clearance around the washer to allow for expansion laterally when compression is applied vertically, then if the rubber is for example 6mm above the edge of the cup it will give an indication of how much force is being applied when the rubber "spring" is compressed down to the edge of the cup.......thicker rubber= more spring pressure.
You can calibrate the washer set-up by measuring the force to compress a series of progressively thicker washers until you get to where you want to go.
Ian.