On Monday 10 August 2015 08:34:53 andy pugh wrote: > I recently replaced the cam-chain on my motorcycle. > > I am not sure I needed to, the new one I bought wasn't very much > shorter than the old one. > Examining the drive, it appears to be zero-backlash and to work with > normal involute-toothed gears. > In fact, it seems like an ideal drive for a CNC axis. It should be > stiffer than a toothed belt, much stronger and (according to > http://www.promsnab.info/catalogues/bosch/tooth%20chains/inverted%20to >oth%20chains.pdf quieter too). They are also known as "silent chains" > so there might be some truth in this. > > The requirements of a camtrain drive are very similar to those of a > CNC axis, and it is interesting to note that the other main-player in > camtrain drives is the toothed belt. > > An inverted tooth chain can run in oil. There are belt-in-oil camtrain > drives on some engines, but I think that they are specially > formulated. > > The cam-chain I removed had done 100,000 miles, most of it at 5000 rpm > or more. (and up to 14,000 rpm)
The camchain in the last Honda I had, a CB350F was still in good shape at nearly 90 thousand miles when I sold it to the next owner for more than I had paid for it with a bad alternator stator and the drive chain and sprockets all run out. Previous owner never knew what a can of chain lube was for. A sprung shoe tensioner kept it from chewing on the rest of the bits & pieces. On that small an engine, it spent lots of time north of 9 grand, up to 12 when asking for max giddyup. I used it for a chair car as the other rig was a 28' Pace Arrow, putting 33 thou of those miles on it in 14 months in and around Janesville/Susanville CA. If one had the breaker tools to make it the length needed, it probably would have been long enough to do all 3 axis's on a regular T.T. mill similar to this GO704 I am working on now. The direct drive motors hanging out do make it a space hog, X in particular. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
