SP-15 maximum sheet size?

Hello, I posted once previously regarding the SP-15 I recently bought and have been cleaning up. This is taking longer than I thought but it is looking better! Meanwhile I’ve been reading and enjoying learning about the press. I am somewhat confused, however, about the maximum sheet size which is listed as 14-3/4 x 20 inches in the specs chart. Measuring from the end of the deadline at top of the bed to the deadline at the bottom, I come up a space of approx. 17-3/4 inches. I would like to understand the reason for this discrepancy as I’m considering purchasing a boxcar base for photopolymer work and the length recommended to me by the manufacturer is 19 inches. I am concerned about the grippers hitting it as it will extend past the deadline. The manufacturer assures me he’s sold this size to other owners of SP-15’s and has had no reported problems so there must be something I’m not getting here.

Also, I’ve posted a few photos of the press at the below address and would appreciate any general comments about it’s condition you might have, thanks!:
“http://www.scdesign.net/press_images.htm”:http://www.scdesign.net/press_images.htm

SP-15 maximum sheet size?

12 thoughts on “SP-15 maximum sheet size?

  • April 23, 2007 at 4:49 pm
    Permalink

    Gerald, thanks for your suggestions. I’m still a ways out from buying a base for photopolymer, but am trying to anticipate potential problems.

    Fritz, I do have the feed board. About the knob, If the one Dan is sending doesn’t do the trick, I would definitely like to order one from you. So far I am having a devil of a time getting the gearshift knob that someone stuck on there to unscrew. I may have to take it to a local machine shop for help.

  • April 22, 2007 at 1:15 am
    Permalink

    The knob is CM-37, if that’s the one I see is needed, and I have a box full of new ones. Knobs are attached using a drop of locktite on the threads. A new feed board can be made, but to specification, they are not inexpensive by any means, and ones we would furnish would be to the original blueprints–remember, one of a kind is not like making 20 or 30 at a time like Vandercook did. I am missing a couple of parts, and I can assemble a bunch of new side guides. I’ll look into doing that. I have many of the parts people are looking for–you just have to ask.

  • April 21, 2007 at 10:41 pm
    Permalink

    Sylvia

    Before you do anything I would suggest that you try printing the full length of the press bed to see if your press can even do the job. The SP-15 has some really small diameter rollers and they may not be able to cover the entirety of the bed no matter how long your base is (I’d actually recommend buying smaller bases that can be joined together—bit more security to that, for a number of reasons).

    You can get an SP-15 to cover the full length of the bed by adjusting the cylinder bearers but you will sacrifice a significant bit at the near edge of the bed to the cylinder. About 1-3/8 of an inch. Bit of a problem with book work.

    Gerald

  • April 20, 2007 at 10:33 am
    Permalink

    Dan, yes, thank you I’d like to buy the knob from you and switching it as you suggest is a great idea. Do you want to send me a paypal request?

    Thanks to everyone for their thoughts and advice.

  • April 20, 2007 at 10:27 am
    Permalink

    Eric,
    Thanks for the correction. I’ve actually never seen the Maravelas book. Other than these errors is it any good? I probably would have ordered a copy, but the cover is just so darn ugly…

    Sylvia,
    Previously you mentioned wanting to replace that shift knob with a Vandercook original. I have gone through my spares and found one, but it is damaged. If you are interested in it I can send it out to you for $5 postage paid. I would suggest you swap it with the pristine knob on your automatic washup (identical I believe) and use the nicer one on your roller mechanism. Here is a photo of the knob I have. It is possible that NA Graphics still have new originals and that would be even better.
    http://www.flickr.com/photos/thearm/465503767/

    Dan

  • April 20, 2007 at 10:09 am
    Permalink

    Daniel, you are confusing work-and-turn imposition with work-and-whirl (also called work-and-twist). Maravelas is absolutely wrong about this (as he is about sinkers). His book is worth a reading, but older books are better to learn actual trade practice and terminology, even if they don’t mention Vandercooks (Mills, Cleeton & Pitkin, and the Polks knew printing and also how to teach it).
    Work-and-turn has front and back form locked up together. On second pass you use same gripper edge but flip sheet over maintaining guide edge. Sheet is then cut apart yielding two (or more) sheets printed both sides. By definition, it is not for broadsides.
    Work-and-whirl form has complementary elements of a single side. After first pass, tail of sheet is whirled to use as gripper edge. Cross-rules or numbering machines are common reasons for this imposition. But this is generally used for two or more up. Whirling the sheet to add to image area limits of a one-up broadside is using work-and-whirl methods, but I don’t think it would properly be called work-and-whirl imposition.

    As for oversize bases, you have to take into account the grippers opened or raised by thick paper as well. I think using a Boxcar base larger than your actual image area could just lead to unecessary damage if careless (or if you’re using a Handy Lockup bar instead of a fixed tailbar). It is much higher than head and tail bars or furniture, or bases used with photoengravings.

  • April 19, 2007 at 1:01 pm
    Permalink

    As to hitting the Boxcar base…

    I just tried rolling the cylinder to the end, put a Boxcar base under the press and slid it until it seemed to hit the grippers.

    That didn’t occur until 21.5″.

    So, it seems that if you put your 13″ x 19″ Boxcar base as near the cylinder as you can (obviously without the grippers hitting it) you should have at least 2.5″ to spare and the end of the cylinder movement.

  • April 19, 2007 at 12:45 pm
    Permalink

    Sylvia,
    I forgot to mention is that if you try to run your form past the dead line even if you don’t squash it you ARE going to run out of cylinder surface with which to impress it. That Boxcar base will fit, but you should still honor the Vandercook specs on the printed area when you begin setting up jobs. One way getting around these limitations is by using a ‘work and turn’ method. Michael Babcock of Interrobang Letterpress has done this on the SP-15 on some of his broadsides shown here:
    http://www.interrobangletterpress.com/html/portfolio/broadsides.html

    Dan

  • April 19, 2007 at 12:42 pm
    Permalink

    As to how it looks, I would say you need to do some printing with it and get it a bit dirtier.

  • April 19, 2007 at 12:27 pm
    Permalink

    Sylvia,
    There is a big difference between the max form size (14×18″ on the SP-15) and the max sheet size. The general consensus seems to state that it is best to get a base that has some wiggle room to move on the bed of the press to aid in registration.
    We need to do something about that shift knob. I will check my box of spares and get back to you.

    Daniel Morris
    The Arm Letterpress
    Brooklyn, NY

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.