My 15-21 has a history of the carriage rollers and ball bearings seizing up now and then. This makes moving the carriage very difficult and printing impossible. The last attempt I made to loosen them up involved a vacuum jar and motor oil. The grease inside the bearings was dry and (let’s just say…) “crunchy”. The oil was worked in with a drill mandrel spinning the bearings to loosen up the old stuff. What I would really like to do is replace them at this point. Has anyone out there done this? If so, where did you get the rollers and bearings. I have a request in with NA Graphics but I’m not hopeful they’ll be able to supply the parts. I imagine a lot of Vandy’s have the same issue. Would love to hear some feedback / suggestions. Thanks!
Carriage bearing replacement.
First, the carriage will have to be removed, Note the last cylinder gear tooth indexed to the gear rack.
Remove the end plates and bumper blocks, then roll the carriage off the press supported by an engine hoist or two very strong humans and placed on wood blocks
Wood blocks should be arranged to allow the bearings to be extracted while supporting the weight of the carriage.
Note the position of each eccentric before removing them from the carriage side plates.
Carriage bearings are staked to carrier eccentrics. Their removal and installation on the eccentrics can be done by a machinist.
Bearings are measured at the outside diameter, inside diameter, and width in millimeters (the system used for new bearings).
Stake new bearings to the carrier eccentrics.
Reinstall each bearing, matching the original eccentric positions, tighten the lock screws after reinstalling the carriage.
The tolerance (gap) between each bearing and its corresponding rail is .003”. Use a feeler gauge to measure. Long gauges can be purchased form an industrial supplier such as McMaster-Carr.