Posted by John Collins (194.164.38.95) on June 03, 2003 at 23:36:48:
In Reply to: Question for John Collins posted by David on June 03, 2003 at 13:08:30:
Hi David? (I've lost track of who's who with all these signatures.)
I wouldn't say my design's complete until it works. One thing I've learned over the last two or three years is that there are an almost limitless number of ways to vary a particular design. No wonder JB spent so much time on it. He was fond of saying that the reason that he succeeded when all others had failed was because he never gave up and spent hours and hours every day doing nothing else but try different designs.
I don't spend hours every day (actually I do sometimes) working on it but I think I have made some progres in that I have the basics of the mechanism. Getting the relative sizes of each piece and the positions and the numbers right is, for me, a case of trial and error.
I know we should be able to predict what will and won't work, but in practice that is not the reality. There are numerous instances in my own experience when the mechanism does not react to a change in rotation in precisely the way that I have predicted and an adjustment of one kind or another must be tried.
Computer simulations simply don't work in this case because it is not possible to put into it information sufficient to allow the program to make an accurate prediction. I know many of you are fond of CAD but I am afraid that some CAD designs may be shown not to work and be jettisoned and a potential design lost, when all it needed was some slight adjustment not perceived because it was on a computer rather in the form of an actual piece of moving mechanism.
You cannot beat the feedback that you get from handling the real thing and moving it back and forth to get a feel for the way it reacts.
Anyway to answer your question, I don't know! I'm working on it and that is all I can say for definite - it could be years away yet. Sorry.
JC
: Hi john. Is your design complete? Any idea time frame of when you will have the machine finished?
: D.