Are there other methods of cutting precision gears other than with a mill or lathe and indexing head? I am wondering if I have overlooked a potential process/method where I can cut gears using other equipment or processes without buying a huge milling machine and indexer? I think they used to cut gears by filing them by hand in old times but I'm not sure how accurate this will be vs. using more modern tooling. I'd like to make a mechanical clock but its been 4-5 years now since I first wanted to make a clock and still haven't had the time, space or cash to buy a mill. Maybe a smithy machine is worth it in this regard but I'd be severely limited in terms of the size gear I could cut.
You don't need a lot of space for a small mill and lathe. Look at the chick on youtube.... Blondihacks She has a cute lathe and mill and both look like pretty capable machines from what I've seen. Little machines must be the rage these days. I see many guys using them.
Gear shaping does not require a indexing head.. It is a old school method not used much as it is slow. http://www.engineeringenotes.com/in...-machining-gears-machine-tools-industrial-eng
I presume you're aware of Clickspring (and many others) on YT? Gears can be cut by hand, it will take quite an investment of time, but it is possible and many have made absolutely gorgeous pieces that way. If you're willing to forgo a lathe and mill, you may want to consider a die filer; can even cast most of the parts. If you do cast one, but find you need machining done, a pop over to hobby-machinist.com might yield someone willing to machine two and return one.
Depends the size and accuracy you're after but for something as light duty as a clock they could easily be 3D printed using the as printed material. For the higher wear pieces early in the movement, lost PLA and brass/bronze might be a possibility. When I was in high school, wooden clocks with wooden gears were popular projects and kept remarkable time for what they were. Best, Kelly
The gears don't really need high precision with respect to concentricity, tooth size or shape. In a clock they are mainly counting devices, not precise displacement devices. Clickspring is someone to definitely check out in this respect. Denis
If wood and wood based products options are on the table, I can only suggest not to bother with this particular example, unless maybe they put it out as a printable pdf someday - anyone who tells you they X-acto'd out, scored, folded and glued up the big main cardstock gear wheel perfectly on the first try is lying! https://www.amazon.com/Make-Your-Working-Paper-Clock/dp/0060910666 Jeff
Yes I saw clicksprings video and it was very helpful but he cuts v shaped teeth rather than the proper modern shape. He also filed them by hand which I feel like is going to be a painful exercise or impossible if I'm trying to do modern tooth patterns. A scroll would help hog out the main shape of the teeth and then maybe a file to finish them up? Do you think I could stencil on the modern tooth shape and file it to match with any accuracy? I want to make a large grandfather type clock with a new octopus sculpture interacting with it in some way.
Hmm that's interesting I had always thought they needed to be machined very precisely or they would not be accurate time keepers. But that makes some sense too. They count out seconds.
The precision comes from the accuracy of the pendulum timing and its consistency of periodicity. Denis
Do realie that in many of his videos he's replicating some very old devices (up to about 2000 years old) from before the involute form was likely known. The lathe and mill are very new inventions compared to clockwork/clocks; all the old stuff was hand made. In that regard, I think clickspring's videos are very useful as he shows methods of dividing, fitting, and manufacture. If the intent is to build a mechanical clock, I think Kelly's suggestion of 3D printing would be the best. If you were happy with the result and later wanted it from brass or other metal, you'd at least know the design works satifactorily.
Hmm. I'm looking at buying brass sheet stock in the 1/4" thick range (too thick?) since I think it will be easier to cut gears onto/work with, however the price of material is a big absurd. Anyone know a good place to buy sheets of brass for cutting gears? Or if not, what other metals would work as a cheaper substitute?
I guess you already considered casting the gear blanks? Maybe you could use some old bronze sprues and avoid buying new metal that way. Lost foam would be quick and easy. Jeff
Maybe 12 to 15 inches across? I haven't seen a specific resource with gear thickness recommendations yet. Casting blanks might work but my lathe isn't properly set up yet and my 3 jaw chuck is terribly out of alignment. And machining all the gears would take a long time. I don't have access to the lathe during most of the year. If I had sheet brass then I could file and cut the gears in my apartment slowly over the year.
I suppose steel is out of the question? But should it be? In thinnish sheet like 1/4" it would not be that much more difficult to file than brass provided you were using good sharp files. And the gears could be quite attractive and resistant to rust if polished. I particularly find "spotting" attractive (think the cowl of the Spirit of St Louis) for such gears. Spotting is very easy to do and has a long horological tradition for just the reasons stated. https://www.circuitousroot.com/artifice/machine-shop/surface-finishing/spotting/index.html Engine turning is another term for a very similar process. I've done it on a few things and I love the way it looks. Also the use of hardened steel guides for filing can reduce the tedium of profile filing and improve its accuracy. Denis
