wb9omc@ea.ecn.purdue.edu (Duane P Mantick) (11/28/89)
Darn..Iforgot to get the guys name.... Someone posted that they were having the tops of letters cut off on their daisywheel printer. There are several things to check for that can be done fairly easily: print something, and then remove the ribbon. Look on the ribbon and find out where the petals on the wheel are striking, relative to the top and bottom of the ribbon. Most daisywheel printers seem happier when they are striking in the center 1/3 of the ribbon. If you notice that the telltale "wear line" is occurring VERY close to the top of the ribbon, then what is happening is: everytime you do something which does NOT cause the ribbon to maintain tension (varies from one printer to the next), the ribbon can be pulled down or simply droop down. the first few characters that are printed will probably get cut off until the slack is pulled out of the ribbon. In the above case, you would need to adjust the ribbon height. Many printers have an eccentric screw and locknut - you loosen the locknut and turn the eccentric until you're striking in that magic center 1/3, then tighten the locknut again. Sometimes, you get a printer that has no such adjustment and simply has a worn carriage assembly. You can kluge the ribbon upwards (sometimes) by wedging a chunk of paper or tape under the case of the ribbon. Not ideal, but functional. Another occurrence: say you want to start printing halfway across the page (indentations for whatever reason). The simplest way MOST people find to get there is just to throw in as many SPACES as required using the space bar. DON'T DO IT IF YOU CAN "TAB" OVER! The physical vibration of spacing over (caused by the stepper motors in some printers) can shake the ribbon loose and cause a similar symptom to the one the poster noted. If you set tabs and use them (and IF your printer knows how to deal with them) the carriage will smoothly tab over and start printing with a minimum of "shake". And last but not least, the platen height problem. More often than not, the vertical position that a print hammer strikes the petal on a daisy wheel in mechanically fixed. The ribbon can be adjusted vertically. So can the platen and/or print bar. Printers equipped with a rotating platen more often than not have a vertical platen adjustment. In the case of the posted problem, if the platen has slipped down far enough, the tops of the characters will get cut off. Remember that the platen has a curved surface - if the platen is low, the face of the character would have to bend over to leave an impression on the page. A plastic daisy wheel CAN bend, but only just so far, beyond which you are left with a gap in the top. All of the above can be prevented by checking the aformentioned adjustments against the tolerances in the maintenance manual - IF you can get one! Duane Mantick Purdue University Engineering Computer Network ------------------------------------------------ the above posting has little or nothing to do with my employer - except that I fix printers!