This topic contains 1 reply, has 1 voice, and was last updated by Charlie Rand 2 months, 3 weeks ago.
- 27/01/2019 at 7:46 pm #5381
I want to make myself a press similar or identical to the one I have seen on Gavin’s video (somewhere ).Can anyone here explain the maths and physics in springs ,in layman terms , so that I can go and choose one and calculate the pressure my press will exert etc.
Thomas26/02/2019 at 6:23 am #5520
There is a law in Physics called Hook’s Law that says:
F = k*x
F is the force applied to the end of the spring away from the force applied. This works for compression as well as stretching. Think of the press as the part applying the force and the follower in the mold as the part getting force from the spring. The formula assumes that the spring is horizontal, but it works just as well vertically. Consider that at rest, the value F = 0 because x = 0 (the product of 0 and any number is 0).
We could calculate the “k” in a spring by applying a varying forces to the spring on a scale, measuring the compression distance and doing the arthritic (k = F/x). Note that you should take several measurements to verify this. k is known as Hook’s Constant (it’s not that physicists can’t spell, C stands for something else) and if you look for a spring online, it’s sometimes called “rate” and it’ll probably be measured in pounds/inch.
All that is a very technical way of saying that when a compression spring is pressed, the force on the other end is directly proportional to the distance of compression (in Math and physics, we say that this relationship is linear). This is why some cheese presses have little rulers on them.
If you live in a part of the world that uses metric, the units are: F is in Newtons, x is in centimeters or meters and k is in Newtons/meter.