In previous posts we discussed several tips to fix signature registration problems in saddle stitched books, most of which are helpful for both signature pockets as well as cover feeders. Once the book passes the cover feeder (or the first pocket if you don’t have a cover feeder) it passes into something of a no man’s land prior to the stitching unit. Today we'll look at two more tips to help in this area.
Even though this ‘no man’s land’ is a short stretch considering how far the signatures have traveled, there is still plenty of room for bindery gremlins to do their work. Covers pop out of position and caliper squeeze or chain vibrations can create mis-register. Of course the overall objective is to keep all the signatures aligned to the head until the moment they’re stitched. In a perfect world this would happen with a normal make-ready, using only manufacturer supplied components. The reality is that there are weaknesses in even the best-designed machines and normal wear and tear can gradually give rise to such problems.
Many of you wrote to suggest the use of various brushes in this area, strategically placed so as to prevent or correct any mis-register happening here. The photo at right illustrates a clever home-made setup which allows for movement of the brush and adjustment of pressure to suit the job. (Thanks to John Johnson, Bindery Manager of Davis CGS for submitting the photo!)
Another handy spot to attach joggers is the cover feeder itself, and shown in the photo. Card stock, steel banding, rubber hose, spring steel or other flexible material can be attached to keep the cover in position. You can also cut a v-shaped notch in the card as a way to adjust pressure on the book. Many stitchers come equipped with spring steel joggers with a pre-cut notch.
Use both techniques for added insurance and carefully look at any location where the book is ‘free’ from any positive control. That could be the spot where a mis-register occurs. Although the quick fixes mentioned here are aimed at keeping the cover lined up, if there aren’t too many signatures in the book, a well placed brush or other jogger can help line up all the signatures if they aren’t too far out of register. And it sure beats having a person sit there jogging them up by hand!
One common sense item bears repeating—be sure the basics are checked first. Pocket timing, sword height, air adjustments and any features particular to your saddle stitcher should always be correctly set. No amount of bindery tricks will fix a sloppy setup or a hasty shortcut.
Your comments and suggestions are welcome below.