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!