Hi Greg, It does help, indeed. The brass sleeve on my friend's machine rotates but does not seem to be pulled out. I'll have to watch this further.
Ron. -----Original Message----- From: phono-l-bounces at oldcrank.org [mailto:[email protected]] On Behalf Of Greg Bogantz Sent: Saturday, August 30, 2008 2:38 PM To: Antique Phonograph List Subject: Re: [Phono-L] Columbia BC friction wheel drive Ron, it's difficult to explain the BC friction wheel driveshaft system without pictures or handwaving :o) The drive train begins with a gear-driven piece of metal tubing which is enclosed in the stationary outer housing which is fastened to the gear housing casting on the side of the machine. This first piece of tubing (call it part 1) rotates but does not translate axially. Inside this rotating tubing is the brass coupling sleeve (part 2) which can rotate and also slide along its axis. And inside the brass sleeve is the solid rod (part 3) which connects with the amber wheel. This part 3 rotates and also slides axially. Part 2 has two slots, diametrically opposed and milled into its outside surface that run almost the full length of the part. Part 1 transmits its torque via two setscrews which extend inward from Part 1 into the slots milled in part 2. (Access to these screws is via a hole drilled in the stationary outer tube.) This allows Part 2 to be rotated by part 1 and also to slide axially inside part 1. Part 3 has a "T" shaped fixture at its end that engages two longitudinal slots milled INSIDE of part 2. This is what transmits the torque from part 2 to part 3 and also allows part 3 to translate axially. The slots inside of part 2 do not extend all the way to the ends of part 2. When part 3 is pulled along the mandrel with the reproducer, its T fixture hits the ends of the slots inside of part 2 and thereby drags part 2 along with it axially. All this assemblage has a purposefully sloppy fit to allow the amber wheel end of part 3 to wobble around radially so it can follow the stylus assembly as it is raised and lowered from the record surface. Clear as mud? Again, it's hard to envision what's happening without seeing the structure in detail. But maybe this helps understand it. Greg Bogantz ----- Original Message ----- From: "Ron L'Herault" <[email protected]> To: "'Antique Phonograph List'" <phono-l at oldcrank.org> Sent: Saturday, August 30, 2008 10:38 AM Subject: Re: [Phono-L] Wide Columbia belts and more > There does not seem to be any connection between the brass sleeve and the > inner steel(?) drive shaft. How is the brass sleeve supposed to be pulled > along? > > Ron L > > -----Original Message----- > From: phono-l-bounces at oldcrank.org [mailto:phono-l-bounces at > oldcrank.org] > On > Behalf Of Greg Bogantz > Sent: Saturday, August 30, 2008 2:32 AM > To: Antique Phonograph List > Subject: Re: [Phono-L] Wide Columbia belts and more > > The brass sliding sleeve is part of the telescoping drive shaft that turns > the amber wheel. There are three sections to this driveshaft and when the > reproducer is at the extreme start of the record, the brass section sticks > out of the left side of the support casting. But when the reproducer has > extended all the way to the opposite end of the long mandrel, the brass > section is pulled with it as the driveshaft extends. > > Greg Bogantz > > > > ----- Original Message ----- > From: "Ron L'Herault" <lherault at bu.edu> > To: "'Antique Phonograph List'" <phono-l at oldcrank.org>; > <phonolist at yahoogroups.com> > Sent: Friday, August 29, 2008 11:42 PM > Subject: [Phono-L] Wide Columbia belts and more > > >> Oh wise and learned members, Is there anyone who sells the wide Columbia >> belts with stitching as found on machines such as the BG and BC? >> >> I saw my first BC today. It seems to have a modern replacement for the >> vulcanite "shoe". Does anyone have an original instruction sheet for >> this >> baby? I'd like to know what the sliding brass sleeve on the drive shaft >> to >> the amber wheel does, for instance. >> >> Thanks, >> >> Ron L >> >> >> >> >> _______________________________________________ >> Phono-L mailing list >> http://phono-l.oldcrank.org > > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org > > > > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org _______________________________________________ Phono-L mailing list http://phono-l.oldcrank.org
