On Wed, Apr 9, 2025 at 3:22 AM The Doctor via cctalk <[email protected]> wrote:
> Before I saw the photographs I would have guessed that the three sets of > tumbler > stacks would all be pinned identically. In terms of manufacture and > maintenance it > would be both easiest and cost effective. But. > > Photograph number five on that gallery page (nice and simple - I like it) > makes me > wonder. To have a key that would work with all three sets of tumblers it > seems > like it would have to have five cuts on it, not four. The four cuts closest > to No, I thnk it's just 4 cuts. I am pretty sure I can make out 4, and only 4 pins. In each of the 3 positions those line up with the appropriate 4 upper pins. The plug moves back for the anticlockwise position. I must admit I had the same thought initially of 2 key types but I can't see how that would work. > the shoulder would work in the (looking at the lock straight on from the > front) > rightmost and top positions. There should be room in the keyway for the > unused fifth > cut at the end of the key, with no pin stack to engage. However, the leftmost > pinstack is offset backward by a distance of one pin stack, which implies > that it is > pinned for the second, third, fourth, and postulated fifth cuts on the > matching key. > > It would make sense to find key blanks that almost but not quite fit - with a > blade > of the right width and height but ideally without any of the warding grooves > on the > sides (but that may not be feasible). Then grind out wards that match the > weird > parts of the keyway. > > But that might not be practical, either. Using a 3d printer to fab a couple > of key > blanks wouldn't be a good idea, I think. I don't think plastic would hold up > well. It wouldn't (and in my limited experience 3D printed plastic parts are weaker than plastic parts machines from solid anyway). It takes considerable torque to turn the camshaft in certain positions. > > Would it be feasible to cut a couple of key blanks out of metal plate? Maybe > metal > strips? Should be possible to mill them, but as I said I'd want to make several identical ones which is a pain without CNC tools (my lathe/mill are entirely manual). I can't believe it's a custom keyway so blanks should exist for it. -tony
