Ends should be free of burrs and chamfered to allow for easy insertion. minute shaft) with rubber washer, flat washer and nut for mounting.Ģ pcs - 19 mm x 2 mm dia. But nobody wants to hear that their brakes were made with powdered metal parts, which I believe some are.Ī 3-D printer could easily use a mix of powdered metal and semi-solid binding agent, after which the part would be sintered in a furnace, and I believe that this is how it's done.I present to you the Retrograde Clock Model 2ġ2888 clock movement with 4.5 mm length threaded shaft (WHITE SHAFT with 4.98mm dia. One major difficulty is the term "powdered metal" because people tend to believe that finished parts will somehow crumble back into powder, which they will not. A variant containing metal oxides is used for rare-earth magnets, This technique is also used to fashion tungsten carbide tools and, when they existed, the tungsten filaments in light bulbs. I don't know if any clock parts were ever made this way, because it's cheaper to just use die-cast zinc or plastics, but I believe that parts for firearms and bicycle gearing (Sturmey-Archer used it for their 3-speed bicycle hub) were routinely made with molded powdered metal. You can beat on it, and while it might bend, it won't fracture. The cooled part is extremely strong-approximately that of a solid piece-and accurately retains the detail from the mold. Then, as the temperature increases, the granules of powdered metal that remain fuse, or "sinter" into a solid piece that's very close to the shape of our chalk-like part. First, the binding agent burns off in a cloud of fragrant smoke. And so we heat our chalk-like part in a furnace. It turns out that as we heat a piece of metal to just under its melting point it will tend to fuse to nearby particles of the same metal without actually melting. The result is a part of the desired shape, only it has the consistency and strength of chalk and can, in fact, be shaped further if desired. Considerable heat and pressure are then applied, and this fuses the binding agent together along with the metal powder. This composite powder is rammed into a sturdy mold which forms it into the desired shape. Then you mix the powdered metal with a binding agent, which is generally some sort of heat-setting plastic that is also powdered. I do not know how you'd turn metal into a powder, but it's been done for 80 years or so. It's helpful to be familiar with a far older technique that involves powdered metals. It'd be great, and we were supposed to have seen it by now. The plastic burns away and the grains of powdered metal (usually microscopic spheres) weld together ("sinter") and the result is a solid metal structure as strong as one you'd have filed out of a steel block. These are then popped into the furnace and heated to a temperature just below the melting point of the metal. The technique that was going to change the world made parts of a powdered metal bound with plastic on a 3D printer. The general job shop doesn't care what that gear with the funny pointed teeth is used for as long as you're happy with the results and you remit payment promptly. This is exactly what makers of printed circuit boards and the people who make metal molds for plastics with CNC techniques do I've seen the advertisements. ![]() ![]() What is needed is a general job shop: send us your files and maybe a picture of what you need, choose a material from which to 3D print it, and we'll send you your new part within three days. That is a nifty article, but it's five years old now. If anyone knows any more about this miraculous process than I do, I'd appreciate any comments. But there's nothing, and the only parts I can think of that would work with the softish plastics currently in use would be replicas of wood clock wheels or case parts. Though I have a rather elderly NAWCC journal that describes the restoration of an electric clock by means of a 3D-printed plastic gear, it was quite a project and by this time I'd have expected to see Timesavers and them offer a 3D printing service for otherwise-impossible parts. ![]() So the 3-D printed products I've seen have been confined to things like mixing bowls and action figures. My guess is that nobody was able to find a 3D printing material strong, stiff, and stable enough for a machine part, and I haven't seen anything at all about improvements in the precision and resolution of the printers themselves. But I think it's worth its own thread, because I suspect that others may have been as disappointed as I was.ģD printing would have been able to produce those parts almost instantly if everything had gone as predicted, which apparently they did not. This post was meant to be a reply to TH Tanner (I think) who sought a miserable plastic ratchet-gear-coupling-thing for a romantic cuckoo clock.
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