#4 form roller gear rack

I have been perusing the posts related to #4 form roller problems, specifically in regards to the clutch plate. I finally got a good handle on the source of all the racket that my press has been making for the last few months by adjusting the roller assembly and shimming the clutch plate. The issue that I am really curious about and haven’t seen any information about the wear on the gear track where the form roller gears rest. In all the pictures that have been posted of the clutch plate the gears below look like they have been worn down, just like mine. I have heard that a worn down gear track is curtains for a press…is that true?? Also, is this the reason that my press jumps some times when i begin to move the carriage down the track? Any information regarding this matter is greatly appreciated!
Thanks!
Karen

#4 form roller gear rack

2 thoughts on “#4 form roller gear rack

  • July 10, 2008 at 11:23 am
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    It took me a while to find the photos here showing worn teeth, and they show the crowns of the rack gear teeth as pointed, not flat, in the rear position. The starting tooth segments on other Vandercook models (SP, Univ) also have intentionally pointed crowns; it gives the pinion gear more clearance to mesh with the rack teeth. But unlike those other models, the No. 4 roller gear and gear rack teeth don’t unmesh at the rest position. If the teeth were severely worn, then the crown of the teeth on the roller gear could possibly hit the crown of the teeth on the gear rack, or just glance off it, and you would get a jump. You need to determine if the jump only happens at the point where roller gear meets the first flat-crown gears.

  • July 10, 2008 at 12:34 am
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    The gear racks can be replaced (from about $200 to $300 each, depending on press), but I question that there is much wear to them, but I’d need to see what you have. The main problem is with the bronze plate the pins in the roller core hit at the start position and cause the clutch assembly to disengage. We don’t have the pattern for that casting and the groove typically worn in the face of that plate has to be rebuilt with brazing and filing to get the original countour back. This may be what is causing the clutch assemblies to chatter when the cylinder moves forward. Gear racks should have a very light coat of oil only–no grease.

    Fritz

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