Dan how about making a sprocket spread sheet that cover lots of tpi and pitches I for one would be interested in that
You can start with mine and add to it the different threads like your 6 tpi this would be good for using plastic Instead of metal. Bill From: [email protected] <[email protected]> On Behalf Of [email protected] Sent: Friday, October 6, 2023 9:12 AM To: Legacy Ornamental Mills <[email protected]> Subject: Re: Sprocket development Yep, found that out the hard way. Was half expecting it, though. But acrylic should be fine for sprockets because the pressure is spread over almost half of the sprocket instead of focused on a tiny contact point of gearing. Is that a reasonable expectation? DanK On Thursday, October 5, 2023 at 4:21:06 PM UTC-4 Curt George wrote: Hey Dan. Acrylic and Plexiglas are to brittle to work for gears, (at least for the long term.) But I have had luck with Acetal and Delrin/POM H. work very well for the gears that I've made. These plastics work/cut well on the Laser as well. NOTE: I have Acetal/plastic gears meshing up with steel gears for a long time, Only slight ware, even though the steel is much harder then the plastic. NOTE: increasing the speed of the gears is hard ON the gearing, but if you want to slow the gearing down, going small works easy. EXP. my x2,3,4 gear set. Using the 96 tooth gear form the Legacy and 24,32,48 gears also standard gears. (can be found in our archives... https://groups.google.com/g/legacy-ornamental-mills/c/YrTllthCU-o/m/eZ7juNXZBAAJ C.A.G. On Thursday, October 5, 2023 at 03:30:31 PM EDT, [email protected] <mailto:[email protected]> <[email protected] <mailto:[email protected]> > wrote: I wish I had listened to "sprocketman" BEFORE going to all the trouble to make gears to produce a 6 TPI threaded dowel. But then, we wouldn't have the calculators I fussed over. What drove home the point in my thick skull was while working on the sprocket calculator I discovered that a simple pair of sprockets, a 30 tooth and a 20 tooth would produce the desired 6 TPI. DOH. Larger sprockets of 60 tooth and 40 tooth and several other combinations would do the trick. So, CDO (which is OCD in alphabetical order like it should be) is pushing me to find a sprocket and hub system that makes changing very easy. It looks like, after a lot of searching, that LOM owners will have to build their own hubs. Going further down that path, a pair of special hubs which hold type A plate sprockets would be desirable, one for the driver and one for the lathe. Then it dawns on me that 1/8" acrylic is easily cut into sprocket shapes and is durable because the teeth are relatively large and the load is widely distributed. And cheap. So, putting it all together, three special hubs (one to hold the plates for machining the mounting screw holes and sprocket roots), an idler sprocket, and a length of #25 chain are all that's needed for a base system. That sets up a scenario where a desired pitch can be had by cutting one or two sprockets from acrylic. There are online calculators that draw the sprockets to scale for printing and subsequent machining. The range of pitches is quite broad, adds a few to the gear pitch range and is a good alternative to the gears LOM made for the overlap. In other words, it opens up opportunities for those of us with limited budgets and can't find the needed gears. So that's what I'll be pondering for awhile. Any recommendations on sprocket hole sizes? To keep the plates flat and easy to make, I'm thinking the hub to have a 3/4" diameter stub for centering the plate and a pair of screw holes to hold the plate to a flange which would have to be at least 1 1/4" diameter. If the center hole for mounting the hub can be smaller, then perhaps a 1/2" diameter stub reducing the flange needed to about 1" diameter. Either way, the goal would be to make the hubs so they will hold sprocket plates interchangeably. Universal within the range of the machine's capacity. DanK -- You received this message because you are subscribed to the Google Groups "Legacy Ornamental Mills" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <mailto:[email protected]> . To view this discussion on the web visit https://groups.google.com/d/msgid/legacy-ornamental-mills/c79fc0d0-ef33-4797-9ad8-8f4a7f2c74b3n%40googlegroups.com <https://groups.google.com/d/msgid/legacy-ornamental-mills/c79fc0d0-ef33-4797-9ad8-8f4a7f2c74b3n%40googlegroups.com?utm_medium=email&utm_source=footer> . -- You received this message because you are subscribed to the Google Groups "Legacy Ornamental Mills" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected] <mailto:[email protected]> . To view this discussion on the web visit https://groups.google.com/d/msgid/legacy-ornamental-mills/65729de3-333a-4772-9d73-cf2c17e35076n%40googlegroups.com <https://groups.google.com/d/msgid/legacy-ornamental-mills/65729de3-333a-4772-9d73-cf2c17e35076n%40googlegroups.com?utm_medium=email&utm_source=footer> . -- You received this message because you are subscribed to the Google Groups "Legacy Ornamental Mills" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/legacy-ornamental-mills/000901d9f7e2%2437cafde0%24a760f9a0%24%40mmnet.com.au.
