(snip, I wrote) >> From one 1403 manual, I see some gears that are specified for 50Hz >> and for 60Hz, but I am not sure what they do. As far as I can tell, >> the train is powered by a synchronous motor (or close enough). >> I presume you don't want the train running 1.2 times as fast.
(snip, John Eells wrote) > The print train (or chain, depending on model) in 1403s was direct > driven. The vertical motor shaft was keyed to the print train. > If the motor speed were to change, the hammer flight timing set in the > 2821 control unit would be far off, resulting in the printing of partial > characters at best. Whether they compensated for this with motor > wiring, a different motor, or different flight timing settings, I have > no idea. (The factory took care of that stuff!) > I don't recall any gears in the 1403, so it would be interesting to know > where any were that got changed for operation at 50Hz. Are you sure > they are gears and not hydraulic unit drive belt pulleys? https://ia601603.us.archive.org/35/items/bitsavers_ibm140xSY2nd3MaintManualDec71_21919776/SY24-3395-3_1403_Models_N1_and_3_Maint_Manual_Dec71.pdf See page 31 (or 1-26). Induction motors run slightly slower (they aren't perfectly synchronous) than some integer fraction of the line frequency. At 60Hz, one might run at 3500 RPM or 1750RPM or 1150RPM (a little slip below 3600, 1800, and 1200). A 50Hz motor might run at 2900 RPM or 1450RPM or 950RPM. But it isn't hard to change the gear coupling the motor to the chain or train, such that the speed is right. -- glen ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
