On Mon, Mar 10, 2014, at 11:09 PM, Gene Heskett wrote:
> Damn John, I just counted it twice more and got 31 both times. > At a top of the tooth diameter of 1.803, where the heck does that leave > us/me? > > > The smaller driver pulley, is .976" across the top of the teeth, and 17 > teeth, .388" between the flanges. So a .375 wide belt will fit, as will a > 9.5mm wide belt. But a 10mm will be pinched until it burns up the flange > anyway. > OK, we have two data points: 17 teeth and 0.976 OD, and 31 teeth with an OD of 1.803. We also have two unknowns, the belt pitch and the distance from the OD to the pitch line. That should be solvable. Wait a bit while I try to do math. OK, math done. The pitch comes out to 0.1855", which has me mystified, because I've never heard of such a thing. (I've done a fair bit if tooth- belt research for different projects.) I did some googling for 3/16" pitch belts. I stumbled across a few similar tales of woe on various forums. Eastern lathes with belts of approximately 3/16" pitch, and nobody able to find spares. http://www.cnczone.com/forums/general-metal-working-machines/112495-timing-belt-available-lathe.html http://madmodder.net/index.php/topic,5006.msg56077.html?PHPSESSID=tef5o88m42hje4vlt64jolptb2#msg56077 One person said: >> I believe that Roman is correct on the 3/16" pitch. This is an old >> design from the 50's or 60's and was know as an F profile. There >> were never any standard sizes and molds were just purchased >> for a specific OE project. The bad news is that very few F profile >> belts are still available and would not be something that an >> industrial distributor would be able to get for you. Why a fairly modern Chinese lathe would be using a 50 year old inch belt type is another mystery, although someone in one of those threads speculated that the Chinese factory either had a big stock of belts, or had the mandrel that is used to make the belts. At this point I'm pretty sure it is NOT any modern standard belt profile. How hard would it be to replace the pulleys? XL profile is probably the most readily available and cheapest. -- John Kasunich jmkasun...@fastmail.fm ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
