I am working on getting my recently acquired No. 4 (Serial No. 14509) working and have a couple of questions about how to go about removing the cylinder carriage and getting the gears to line up correctly again.
To give you a little backstory, as far as I know, this press belonged to a fine printer, then sat in a warehouse for several years, then was donated to a school, where it sat again unused. During one of its moves, the carriage stops were removed, so I’m missing the front two carriage stops.
The carriage was removed and then slid back on with the gears out of alignment. When I roll the carriage back until it hits the back carriage stops, the grippers are at about 10 o’clock instead 12 o-clock (if that makes sense).
There were no marks made by previous owners to guide me with aligning the gears.
What I’m wondering is:
How heavy is the cylinder carriage (minus the rollers)? Will I need at least two people, one to hold each side? Should I break it down further?
Any general tips? is it just trial and error?
I’ve talked to NA Graphics regarding maybe machining new carriage stops, but is there any chance of finding them used?
Thank you, any advice is appreciated.
Yes, the cylinder can rotate in the carriage when the cylinder gear is free of the rack.
Got your handbook as a Christmas present and can’t put it down. In relation to retiming (realigning) the cylinder on a no 4, once the long racks have been removed is the cylinder then moved off the short racks entirely so that the cylinder can’t be turned and then wound back onto the teeth? I hope this makes sense?
Denise: You should find that the gear racks on the No. 3 are a single piece on each side. This means that you will need to retime the carriage at the end of the bed after removing the bumper blocks. You will also need the help of two friends.
Would this method work the same way with the No. 3? Thanks!
What you mean is that the cylinder was too tight to turn in print so you had to do it in trip mode.
Print mode can give you just enough resistance to control how much the cylinder moves. Some SP20s also has split racks, but the cylinder is heavy so it can only be turned in trip mode.
Thank you Paul.
That was good news.
One thing I’ll add for anyone that attempts this, because it stumped me for about five minutes. Put the press in print mode, roll the cylinder to the end of the bed so you hear the click, return it towards the feed board and THEN the cylinder will spin freely. I marked the cylinder gears with a sharpie to help me orient myself.
The good news is that on some models, like the No. 4, you can retime (or realign) the cylinder by yourself. The cylinder racks have two sections on each side. First, remove the form roller rack, then remove the long sections of the cylinder racks closest to the end of the press, but leave the sections closest to the feed board in place.
The racks have machines screws that pass through the top and into the bed casting. There are also pins on the ends of each piece aligning the racks to the bed. This means that after the screws have been removed, the racks must be evenly lifted off by tapping an ink knife under the end of the rack and along it’s length. Be careful, because there may be thin plastic shims between the racks and bed. Once a gap has been created you can use a a screwdriver to pry the rack (with the pins) from the bed.
With the cylinder in print mode, roll the carriage forward until the cylinder gears clear the remaining rack sections. Then, if by yourself, hold the carriage steady by leaning it and pull the cylinder forward the distance you believe to be misaligned. Keeping the cylinder steady, push the carriage back onto the racks, then turn the hand crank to bring the carriage back to the feed board. It may take a couple of attempts to get it right.
I doubt you’ll find a used pair of bumper blocks, but they are the same as on a No.3.