I’m teaching a workshop at Northern Kentucky University where they have an SP-15. It’s been many years since I have used this press. We’re having a problem with the tympan paper coming undone at the back. The ratchet that holds the tightening bar in place appears to me to be set backwards, at least it is on backwards compared to my #4. The end that grabs the ridges points downward away from the operator, and this makes it very hard to control. The school doesn’t have a manual, apparently, so I need some advice. If it’s backward, I’d like to set up right side up so that it would be easier to use. I shot some photos but my hosts don’t have any way for me to upload the photos from my camera. Any thoughts? Thanks!
Trim the tympan so that only the Mylar drawsheet wraps around the reel rod. It can also help to cut a new sheet with a longer taper. Remember, if the pawl locks on top of the ratchet then the taper winds under or clockwise around the reel rod, but if the pawl locks under the ratchet then the taper winds over or counterclockwise around the reel rod.
On most models t’s nearly impossible to remove a reel rod.
I have a 219AB with a reel with no clamp or pins. I can’t seem to get the tympan to tighten. Eric says that without a clamp a piece of tape can be used, but I’m having a hard time with that as well. I’m using mylar on top of the tympan and I can’t get both tympan and mylar to stay firmly in place. Suggestions?
Is it possible to replace the bar with one that has the pins and clamp? It’s so much easier to use!
Vandercook used several different syles of tympan reel. I think all their reels that wind overhand used a clamp bar to hold the tail in place as the reel is tightened, and without that clamp a piece of tape may be used; without it the tail will just slide as the reel is turned. The original system had holes punched in the tympan tail and matching pins on reel and clamp bar.
The reels that tighten underhand use the tension of the tympan pulled against itself, and use no additional clamp. The split reels also rely on tension of tympan pulled against itself. This tension is how tympans are drawn on most cylinder presses.
When the tail is tight enough, the tension will hold the pawl in place, and the tail when tapped will give a drum-like sound. You don’t tighten the pawl screw with a screwdriver as some are teaching now.
Thanks, Paul. I’ll give that a try.
If the pawl locks under (points down) then wind the tail of the draw sheet over the reel rod (counter clockwise.) If the pawl locks on top (points up) then wind the tail of the draw sheet under the reel rod (clockwise.)