Can anyone give me some tips or point me towards a good resource for learning how to change the tympan paper on the roller of the good ole’ No. 4? It’s worn down quite a bit, and it also needs a bit less packing as the impression I’m getting is too deep. Thanks!
Comment, part 3. Arrgh. I guess I don’t know how this works. The picture is here:
Hmmm. The drawing for my comment did not seem to load. I’ll try again…
I drew a cutting diagram for making new draw sheets for my No. 4. It prints out, to scale, on a sheet of 18″ x 12″ paper. I just cut out a 14-5/8″ x 27″ piece of Mylar and trim one end to a taper as shown. Then I use the printed template to mark the hole punch-outs and notches. (You don’t really need all those dimensions.) I was using the old draw sheet as a template, but it was kind of messy and kept curling this way and that. I’ll be happy to send anyone the file for the drawing.
Here is a short series of images that show the sequence of adding a draw sheet after it has been fixed under the gripper bar. Perhaps this will help someone.
If you are cutting your own tympan, be sure to have at least an inch for the hem, the portion under the clamp; score and fold the hem carefully; and cut notches where the screws come through the clamp.
Some people just butt the tympan to the clamp-screws and fold it over, but that gives a shallow hem and possibly a crooked drawsheet.
As Paul notes, the reel varies from press to press, but those with a retaining bar on the clamp need small locating holes at the tail of the tympan. If that’s what you have, keep the original as a template, or get a used tympan from a 4 with the same reel.
Awesome. Thanks a lot for the tips.
The roller, as you call it, is the impression cylinder. The top layer of tympan paper is called the drawsheet.
The resource you seek is the No.4 operatorâ€™s manual. The procedure is applicable to all Vandercook models as well as other makes of flat bed cylinder proof presses. From the No.4 manual it reads:
This terse description leaves out a few salient points:
â€¢ The wrench is turned in the direction in which the tail of the drawsheet is wound. If the pawl latches over the ratchet then the tail is wound under the reel rod and if the pawl latches under then tail winds over the reel rod. This varies from press to press regardless of model.
â€¢ The reel rod has a bit of side to side play to help facilitate tightening of the drawsheet against the cylinder.
â€¢ Over-tightening of the reel rod will tear the drawsheet where the taper begins.
â€¢ Tympan paper becomes brittle with age.
Also, note that the originally supplied wrench was a Â¾â€ open wrench. And if you are cutting a new drawsheet from a tympan roll instead of using a die cut sheet save the previously used drawsheet as a template. I like to make my tail longer that originally specified allowing more paper to be wrapped around the reel rod increasing the tension and eliminating the need for a reel rod clamp bar or adhesive tape on end of the tail.