I have made a new set of mechanisms in new material and when moved by hand they perform as designed, but it's still difficult to get the actions perfect and I have to keep altering the way things are arranged, not because the design doesn't work, but to get the various pieces to work together without either missing each other entirely, or getting entangled and locking together. It is surprisingly difficult to transfer a design which is both in one's mind and on paper into a practical reality. Everything works as it should do when moved by hand, but then you find that under its own steam, so-to-speak, or rather gravity, the levers are either too close and bump into each other, or too far apart so that an engagement designed to occur, misses! There is some flexibility in the levers giving rise to too much lateral movement. But if I tighten them down to limit the lateral motion, they become stiff and don't move easily. I may have to add some kind of lateral bracing to support them unless I can produce a proof of principle (POP) wheel without further delay.
I have found that by altering the order of the pieces I have eventually achieved the best arrangement. The order can be changed throughout the depth of the mechanism, by that I mean, not the plan view, but the sideways elevation. It doesn't alter the way the mechanism works but it does improve and free-up the action.
I had fitted five mechanisms to the backplate but as they were unable to move properly and freely, due to entanglement, I have rearranged them and three are now fitted and working as designed. The remaining two will be done as soon as I can get into the workshop again. On some days I only get ten or fifteen minutes in my workshop and sometimes none at all.
I am doing this on a shoestring, as I always have done, just to make a POP machine, but I have seen estimates of money spent on prototypes, posted on various forums, and I am surprised at how much people spend, because I have spent no more than about £100 (about $160) in the last ten or maybe even fifteen years of modelmaking! I have to admit that some of the models shown are amazingly well engineered, rugged-looking and most impressive, but I suspect I could have built half a dozen rough and ready models in the time it takes to build just one high quality one. In the end we only require a working model to prove the principle, however roughly constructed. Once that has been achieved then a high quality product based on the original design can be built.
And another thing; people often describe the high quality bearings they use to reduce friction but I worry little about friction, as long as there is enough energy to turn the wheel continuously against any friction that is all that is needed. My axle is a threaded rod and it rests in a couple of plastic copper plumbing pipe wall supports screwed to two upright pieces of wood. Cost was less than a pound for a pack of five.