What a great bunch of replies! Good suggestions, all. Even though many of us have been working on these wonderful time- machines for years, and have accrued mechanical intuition as well as experience, it never hurts to be reminded of all the possibilities. Even though I didn't post the original inquiry, I recognize the value of all the feedback and will print out a line-item summary of the broad range of possible issues, to post in my workshop as a reminder and checklist. In focusing on the minutiae, we sometimes overlook the obvious.
Best to all, Andy Baron Santa Fe On Sep 2, 2008, at 7:19 AM, Ron L wrote: > The test you suggest is a good one. I'll do it for sure. However, > I am > pretty sure that the spring could give sufficient energy for correct > speed > at one point (coils slide by one another) and then, as it uncoils, > encounter > an area of sticky old grease, impeding proper release of energy, > especially > since we are dealing with century old springs and equally old > lubricant. > > Ron L > > -----Original Message----- > From: phono-l-bounces at oldcrank.org [mailto:phono-l-bounces at oldcrank.org > ] On > Behalf Of Robert Wright > Sent: Monday, September 01, 2008 11:43 PM > To: Antique Phonograph List > Subject: Re: [Phono-L] Amberola 30 erratic speed > > Last thought -- listen to a cylinder you know well and wait for the > speed to > > drop. Back the reproducer up about 20 or 30 grooves and see if it > does it > in the same spot, within about 3 or 4 grooves. If so, it's not the > mainspring, or anything other than something the carriage encounters > near > that physical location along the feedscrew, whether the contact > point of > half-nut to feedscrew, or the shaft the carriage rides along the > length of > the playback. Forgive me for speaking out of school, but if it were > the > mainspring, it just sems like there'd be no point at which you had > reliable > speed. These guys are the experts, but at least give the 30 this > 'repeatable error' test first. > > > ----- Original Message ----- > From: "Ken Danckaert" <kend at lemur.org> > To: "Antique Phonograph List" <phono-l at oldcrank.org> > Sent: Monday, September 01, 2008 3:37 PM > Subject: Re: [Phono-L] Amberola 30 erratic speed > > >> Your problem is in the mainspring. It needs to be pulled and ALL >> the old >> lubrication removed. 4"0" steel wool and wd40 will do that. >> Relube and >> put >> the spring back in. That will get rid of the problem. DON'T soak >> it in >> kerosene or some other short cut to cleaning. The old stuff has >> got to >> come >> off the spring. >> >> Ken Danckaert >> >> On Mon, Sep 1, 2008 at 12:50 PM, Ron L'Herault <lherault at bu.edu> >> wrote: >> >>> OK, gang, it is time to tap into the lists' wisdom. I'm working >>> on an >>> Amberola 30. The hook came unsoldered and the reproducer needed a >>> rebuild. >>> Those two easy repairs (the spring was in the case)completed, I >>> tested >>> the >>> phonograph and found that the speed is a bit erratic. It will >>> sound nice, >>> then slow just a bit then return to speed for a while only to slow >>> again. >>> The carriage moves easily and the horn bobbles and rotates as it >>> should. >>> The governor is lubricated and the pad has been oiled. There is no >>> evidence >>> of crud or damage to the governor disk. There were a few teeth on >>> the >>> large >>> hear that had a bit of damage but a bit of judicious filing has >>> cured the >>> noise the damage created, and besides, the speed variation is more >>> random >>> than the cycle of the gear noise. I'm thinking that the >>> mainspring may >>> need >>> to be removed, cleaned and re-lubricated but I thought I might see >>> if >>> there >>> is anything else I missed before tearing it apart. >>> >>> 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