Wow. I gotta say, from that description, I'm getting a perfectly clear idea of what the parts look like and how they function, and I haven't even seen the parts in question. Thanks for that, Greg!
best, r. ----- Original Message ----- From: "Greg Bogantz" <[email protected]> To: "Antique Phonograph List" <phono-l at oldcrank.org> Sent: Saturday, August 30, 2008 1:37 PM 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" <lherault at bu.edu> > 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 >
