Comments on: #4 form roller gear rack http://vandercookpress.info/vanderblog/2008/07/4-gear-track/?utm_source=rss&utm_medium=rss&utm_campaign=4-gear-track A forum for all brands of flatbed cylinder proof presses Wed, 23 May 2012 01:56:00 +0000 hourly 1 By: Eric Holub http://vandercookpress.info/vanderblog/2008/07/4-gear-track/comment-page-1/#comment-1991 Eric Holub Thu, 10 Jul 2008 17:23:18 +0000 http://vandercookpress.info/vanderblog/?p=637#comment-1991 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. 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.

]]> By: Fritz Klinke http://vandercookpress.info/vanderblog/2008/07/4-gear-track/comment-page-1/#comment-1989 Fritz Klinke Thu, 10 Jul 2008 06:34:33 +0000 http://vandercookpress.info/vanderblog/?p=637#comment-1989 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 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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