I’ll do moremeasurements, but need to find a better scale. It’s designed to automatically turn on when you step on it. Getting it to turn on when the springbox is set up is a pain, plus it randomly shuts off when it decides you have reached your weight….. so if I pause, it displays what it thinks is the final weight for a few seconds and turns off. I had the lower spring boxes marked out in 1” increments in hopes of getting more data.Don't do just one measurement. Try three more at 2. 3 and 4 inches if you can move the mill knee that much. Then plot a graph and put a straight line through it. Excel can do that or I can use excel to do it if you send me the measurements. The gradient of the straight line is the rate. 66 sounds very high compared with what I supply, 45, 36, 33 and 30. Is it possible that you have one of DD's early experiments?
The springs didn’t come from David, I bought them (I ordered D springs in error) from Coventry Motors in Boston. I used Excel at work… plotting graphs to justify me existence , although that was a few years ago. After I gave up on the scale, I installed what I believe are 2 used C springs which are about 15 3/4” long. The D springs are 16 3/8 and
16 7/16. With C springs installed on both side it reacts in a similar fashion compared to the other bikes. I’m leaning towards just leaving it like that for now and see how it behaves providing I don’t become permanently institutionalized as a result of trying to make a functioning copy of a KVFTT mag.
Thanks for all the help, it’s appreciated.