depth of cylinder problem

The press? A Universal 1 manual. The problem? A severe case of an undercut cylinder. How sever you ask? Say your normal depth of cylinder on a Uni 1 is what? .040 inches? .070 inches? This Uni? .160 inches. What packing can fill it? What top sheet can hold it?

What am I using for packing? .020″ blue board, .010″ mylar, .006″ & .002 Vandercook tympan paper. The grain direction of each is doing what its supposed to under the topsheet. be doing, getting around the cylinder and under the topsheet. Trouble is, the packing won’t behave well enough where the topsheet fits in at the gripper assembly. It’s a jump even Evel Knievel would fear, making registration a worry I hate worrying about. Plus after a few impressions the top sheet begins to looked pretty worried itself right at that edge compromising fold where it meets the gripper assembly. Try two top sheets you say? HA! It will laugh at you and call you names if I shared your suggestion with this unruly beast.

Here’s my thought (and now tell me if this is rock stupid, okay?) I buy a diecutting jacket and (time to fess up, I’ve never seen a diecutting jacket for a Vandercook so yes, I am talking out my keister right now) and I put a healthy portion (how about .090″ = 4 blue boards & 1 mylar) of the .160″ packing under that. Plus the jacket itself would take up some room.Anyone know how thick? .050 inches maybe?

To anyone with Vandercook diecutting jacket experience: Would the jacket be strong enough to strap the packing down from end to end securely? And if it did, would it seem ludicrous to then act as if everything were normal and build up the normal .070″ packing with the standard issue .006″ Vandercook topsheet?

Why ask such a stupid question? Cause such a press exists and it’s in my care and I’d like folks to be able to use it. Plus . . . aren”t those Vandercook diecutting jackets sort of expensive? I’d rather look before I leap into buying one if this idea is buckshot full of holes.

Other than that, gang, any other possible solutions are welcome. Now amaze me with your wit, wisdom and candor. Moxon? . . . that leaves you out.

depth of cylinder problem
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7 thoughts on “depth of cylinder problem

  • October 19, 2007 at 3:40 pm
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    Registered members are welcome to post pics of their presses any time. I have added a new “customization” category for this. Categories can be accessed by 1) clicking the meta data link at the top of the post, 2) selecting the sidebar Archive menu, or 3) typing a term in the sidebar Search form. Pages are reserved for more static information that I compile and manage such as the censuses.

  • October 19, 2007 at 2:48 pm
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    Eric, I like the counter sunk holes & machine screws idea even better. Thanks!

    Paul, this makes me wonder if there shouldn’t be a section dedicated to Vandercook customizations. “Pimp My Press” perhaps?

  • October 19, 2007 at 1:46 pm
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    Paul, trading out carriages may be my last option. Nothing wrong with this Uni’s carriage except for this severe undercut. I share Daniel’s concern that too much mass would be crammed behind the gripper bar, so thin, ultra-thin edge at that clamped end will be key for sure. And okay I wouldn’t mind losing a few points at the head of the page, but certainly not anything close to a pica.

    Fritz, I’ll give an offset blanket under the steel jacket a try, but I’m wary of spongey packing as much as the next guy. I’ll give Bar Plate a call next week and see if they can help.

    Meanwhile, the serial number is 29621 and I’d love to hear more about this weird, weird press. Belongs to the College and we received it from Herb Johnson who grabbed it when RIT’s shop closed up what? 7, 8 years ago now? I’ll post my solution with photos when I settle on something. I’m glad to know that my ideas aren’t all that screwball afterall.

    Terry

  • October 19, 2007 at 1:04 pm
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    You could also make the jacket with countersunk holes, drill and tap the cylinder in alignment, and fix the jacket to the cylinder with machine screws. That is how some platens take a jacket. There’s no extra material under the gripper bar, and some of the packing, the permanent packing, could go under the jacket, but allow for that when planning the holes.

  • October 19, 2007 at 12:12 pm
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    Hey guys,
    I would worry that a thick die jacket will mean too much mass crammed under the gripper bar. And trying to use a whole bunch of conventional packing is bound to make for a spongy impression. Going that route you may as well just get a rubber under blanket. That’s all fine for a newspaper proof, but not for fine printing.
    If I had this press I think I’d take a piece of cold rolled steel and wrap it around the cylinder underneath the packing to make up some difference. You could get Bar Plate or another machinist to curve a piece just as they would for one of their shirttail jackets but leave the gripper bar end and the shirttail off. Then it won’t be a big fight to bend it into shape each time you change the packing. 10 gauge cold rolled steel is .1019. This would leave you with .581 remaining undercut on top of it. That is much closer to the .040 undercut of the standard Uni I. If you can find 9 gauge (.1144) that’d be even better!

    Daniel Morris
    The Arm Letterpress
    Brooklyn, NY

  • October 19, 2007 at 12:36 am
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    Typical die jackets are .030 or .060 and the thinner one would be around $240 being made of stainless steel. How about putting an offset blanket at .067, then the die jacket at .030, then regular packing on top. The lead edges of the tympan can be glued together to make an edge that won’t “shingle” and that could provide a sharper edge for the top sheet or tympan.

    Terry–what’s the serial number? Looking up the original owner may give a clue to this extreme undercut. The cylinder can be built up and reground, but I think that is significant money.

  • October 18, 2007 at 10:34 pm
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    Bulking up the cylinder with a die-cutting jacket is an interesting idea my verbose friend. Fritz can have a custom one made and you should be able to order a thickness up to .080”. Ask if the clamped end can be milled thinner to minimize how much the gripper bar projects out. Otherwise you will have to increase the width of your head dead bar on the bed. In any event, you will need longer gripper bar screws.

    Another option might me to have a machine shop build up the cylinder’s face. Although, it may be cheaper to locate a cylinder salvaged from a damaged press. I hear they tip over during moving from time to time.

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