On Thu, Jan 25, 2007 at 08:37:27PM -0800, Normand Martel wrote: > Hi Tom... > > Not only Telechron were very popular electric clock > movements, they were BY FAR the very best mechanical > movements ever made. > > When young, i've opened A LOT of used > electro-mechanical clock movements, and most of them > showed evident traces of wear. Worn-out gear pinions, > dried-out and seized brass/steel bushings, dried-out > and cracked nylon pinions (Nylon tends to harden and > shrink with time and heat, so Nylon parts shall NEVER > be put on a traction stress when manufactured) were > frequent on old clock movements, but NEVER on > Telechrons, except very > rare cases of pinion wear on the output shaft (3.6 > RPM) > > Telechron movements were very unique. The motors were > two-pole shaded pole synchronous motors with an > external solenoid and a completly sealed rotor > stuck within the poles pieces. The self-starting > rotor, composed of three spring steel disks forced in > place on a smooth shaft and spinning at 3600 RPM (60 > Hz) was inside a sealed cylindrical aluminum gearbox > (older gearboxes were in a copper sealed box) > containing not only the rotor shaft, but also a 1000:1 > reduction geartrain. Pinions were made of stacked thin > steel pinion disks forced on the shaft to form single > solid pinions. The faster rotating gears plates were > made of some kind of red-orange colored fiber material > and the slower rotating (higher torque) plates, of > soft brass. The gear holding plates were made of thick > alunimum with a thinner aluminum subplate that > prevented the gears from sliding longitudinally, but > far more important, the thin space between the plates > and subplates had a capital role: Keeping a fine > capillary oil film between the plate and subplate, > that film kept the gear shafts permanently lubricated, > thus eliminating all trace of wear. Even the gears > themselves (the rotor was spinning at 3600 RPM and the > second gear, at 864 RPM) didn't show any trace of > wear, even under a magnifying glass. > > I even remember the gear ratios of a Telechron: > > Rotor: 12 toothed pinion (3600 RPM) > Second gear: 50 tooth fiber plate coupled to a 12 > tooth pinion R:r: 4.1666667:1 �> Third gear: 54 tooth fiber plate coupled to a 18 > tooth pinion R:r: 4.5:1 > Fourth gear: 60 tooth fiber plate coupled to a 12 > tooth pinion R:r: 3.3333333:1 > Fifth gear: 60 tooth brass plate coupled to a 12 > tooth pinion R:r: 4:1 > Output gear: 60 tooth brass plate coupled to an > external 10 tooth pinion R:r: 4:1 > > 4.16667*4.5*3.333333*4*4=1000 > > Definitely a fine movement! I still use an oooold > Telechron at my shop. > > 73 de Normand VE2UM > > --- "Tom Van Baak (mobile)" <[EMAIL PROTECTED]> > wrote: > > > > > See Mitchell's SWCC page at: > > http://www.telechron.com/ > > > > /tvb > > > > > > _______________________________________________ > > time-nuts mailing list > > [email protected] > > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > > > > > ____________________________________________________________________________________ > Need Mail bonding? > Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users. > http://answers.yahoo.com/dir/?link=list&sid=396546091 > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
-- Dave Emery N1PRE, [EMAIL PROTECTED] DIE Consulting, Weston, Mass 02493 "An empty zombie mind with a forlorn barely readable weatherbeaten �'For Rent' sign still vainly flapping outside on the weed encrusted pole - in celebration of what could have been, but wasn't and is not to be no� � _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
