I finally got finished with my new press, based very loosely on Herman’s design.  I’ve made some changes as will be apparent from the pix.  The base is 3/4” plywood, surrounded by 1/2 pine border to channel the whey to the front of the press.  The base is elevated to enable me to place a pan under the base to collect the whey.  You can’t see it in the pix, but the stop is actually the follower with a collar to insert the end of the push bar into so that it does not slip sideways.  I haven’t yet done any calibration to see what the weight to press ratio will be, but it should be at least 6.  If this is right I’ll be able to press at 100 lbs pressure with only 16.7 lbs of weight.

I can’t get all the pix on this post, so I’ll send the remaining pic in another post.

Well, that IS a quite impressive press! Loosely based indeed, but who cares. Most important thing is the resulting cheese!
To calculate the weight to use, I use nowadays the following formula:
Distance on the lever from stamp to point where the weight is pulling, divided by the distance between stamp and hinge.
Multiply that with the weight. In my situation: 42 cm / 7 cm = 6. 6 x 1lbs = 6 lbs.
But when you use pulleys, you have to multiply that with the amount of strings, in your case 3.

Based on your formula, I should be getting a factor of 12.  I checked it with a bathroom scale last night.  With one gallon of water as a weight (8.35 lbs), I achieved a press weight of 88 lbs.  Some of this weight was the accumulated weight of the arm, rod and stop.  So it would appear that I can use a factor of 10 when calculating press weights.  This will really be convenient, since I won’t have to be lugging concrete blocks any more.  I’ll be making a cheese tomorrow with the new press, if all goes according to plan.

Very nice !!