I'm sorry if you think I'm “ being deliberately obtuse in order to score a debating point” David, but you could not be further from the truth. I am simply asking for clarification of some of the statements you are making about rigs that are contrary to my understanding of the subject.
For example, in you posting #10734664 you state, “You know full well that a lower yard angle results in more balance area, lower stresses in the sailcloth, particularly alternating stretching on the bias at the throat , and lower loads on any hauling parrels; all of which makes for a better rig for relaxed cruising”. Er? I don't believe this to be the case. A lower yard angle does not have to have more balance as it is possible to have a lower yard angle and low balance if appropriate parrels are fitted. Also, I don't understand how the yard angle and balance effect the “stress in the sail cloth” as with properly set up cambered sails there should be no stress in the sailcloth, so how can it be lowered? When you add, “particularly alternating stretching on the bias at the throat” I'm totally lost as I don't know what this means. You continue with, “lower loads on any hauling parrels” which I agree can be achieved with lower yard angle and more balanced area, but only if you set the angle of the luff to balance the angle of the leech on tapered panels which is a key feature that you have not included in any of your drawings that I have seen.
In the next two paragraphs you make comments on Arne's rigs, I can only say that Arne has followed a line of development based on the Hasler and McLeod rig and published most excellent information on how to get the best results form that particular rig. He must be congratulated on his continuous flow of helpful information. When he asked, “Could you elaborate a bit on where you have lowered the stress in the rigs with the profile (planform) you prefer, compared to the sails I design, - - ? Should Zebedee and Mingming II have their rigs remade?” it would have been useful to have seen your explanation rather than the dismissive remark about insulting his intelligence. It would appear that Arne is also struggling to understand some of the points you are making.
I am not asking why Weaverbird'srig does not not have much balance, and do understand that letting the battens press on the mast may put less stress on the sailor than would come from luff hauling parrels, but do not believe that it puts less stress on the rig or less compression on the battens which is particularly undesirable with hinges.
In the last paragraph you state,“Weaverbird' - - might well have been wearing a SJR, - - Made according to my own ways of doing things, of course, and having cast a seaman's eye (?) over - - Amiina, and noted some areas where I believe that there is room for improvement.” If you are trying to improve the breed then help by explaining the “areas where you believe that there is room for improvement.” I am happy to change my notes when I learn of possible improvements (as I did a few hours ago when out of the blue I received a call from someone who has been sailing a SJR for about 10 years, to tell me about experiments with combined batten/ downhauls on the yard and top batten).
In my efforts to reduce the stresses when initially drawing the Poppy rig I tried to calculate the slope of the luffs to balance the slope of the leeches and did not find a satisfactory answer, so reverted to model making. As Arne quite rightly points out, the tensions from the main sheet complicate the issue and I do not believe I have found the best answer, but so far it has worked adequately. You claim that the calculations are easy so please explain how to do them so that others can use the technique.
You seem to infer that yard angle, sail balance and rig stress are tied together. I do not look at it that way as I select the yard angle which I feel will give the lowest tip vortex/ induced drag, the balance that will give the most useful camber in the forward part of the rig and a low sheeting load, and only then draw the rig profile to minimise the stresses in the rig. I see them as three separate issues.
David, you must expect to be challenged if you make sweeping statements which contradict accepted experience or appear to be incomplete and omit critical points. I am not claiming to know all the answers which is why I am simply asking for clarification to some of your postings.
Cheers, Slieve.