I recently had my second set of cores recast. In switching out the hardware I cannot for the life of me get the retaining screw to grab and screw in to the new core. I have tried solvents, wd40, a wire brush, an awl and curses, but to no avail. I’ve tried all 4 ends of the 2 cores, and none of the screws want to go in. Is there an ever-so-slightly-smaller version of this screw? Please help!!

15 thoughts on “retaining screw problem for my sp15 cores”

  1. I should add that the early versions of the SP-15 core had a retaining clip on the core end instead of the screw, and if the core is still concentric, they can still be recovered.

  2. I was in contact with Barbara before I took off for the ATF conference. Her problem has been addressed in the above comments–core ends not cleaned out by the roller maker leaving rubber compound in the threads. And possibly the mandrel on the covering machine deforming the core end. A 1/4 x 28NF tap (professional quality, not made in China crap) will clean out the core ends and reestablish any damaged threads. No metrics here and the machine shop that determined that these were metric threads is highly suspect. The roller company should have stood behind their work and their attitude is inexcuseable. I have had a number of rollers remade when they don’t meet spec or have manufacturing problems, and that’s the nature of being in business. Turn out a bad printing job and you should expect to make good on it–the same goes for rollers. Most roller companies are not set up to do letterpress rollers properly, but with the current state of the printing industry, roller companies are willing to make anything to stay in business even if they don’t know what they are doing.

  3. NA does know what the rollers should be, and whenever I have seen a problem with their rollers, Fritz has corrected the error. Letting him deal with the roller company can save you a lot of grief.
    You never want to send any company anything more than the core and its covering. Always remove all hardware, collars, screws, whatever; if not you are making them do extra work, chancing a loss of those parts, and using up whatever patience they may have.
    Exactly where the covering is positioned, and how the ends are finished (square or bevelled) is something that can be a little off no matter where you go. Even NA may send a roller with a bevelled end where that interferes with gear placement, but that is something you can fix yourself with a sharp blade.

  4. barbara tetenbaum

    All is finally well, though I don’t think I will do business with Columbia Rubber Mill again. The general manager (who had no direct contact with my job) deemed both problems (they originally cast the rollers to the wrong end of the cores and so had to recast once already) to be MY fault. He didn’t want to fix the flat spots, but I convinced him in the end and just had them reground. They are now round and in the correct location, and I have hardware to fit the ends. But I’m so pissed at the nerve of this guy to blame me for both mistakes. Not a good businessman.
    Thank you all for your help. I have learned to bite the bullet and send my rollers to NAGraphics to be recast! They always came back perfect.
    xxx Barb

  5. Paul, it has been my experience that most of the threading on later model Vandercooks is National Fine as opposed to National Course (USA). :—) Don’t know if this applies to the models before the SP or Universal series.

    First thing to do when buying a Vandercook is buy a tap and die set with NF threading.

    My reading of Barbara’s problem is just run a NF tap into the core. Sometimes the threads get gunked up during the roller replacement process.

    Gerald
    http://BielerPress.blogspot.com

  6. Barb: Hard to say about the permanence of the flat spot. Because the rollers are new it may work itself out.

    Any vendor who makes an error and wants to keep your business will make it right. And if they are rude about it then just don’t use them again.

  7. If the problem really is distortion of the threaded hole from over-tight chucking, you ought to be able to repair the threads with a tap of same pitch and diameter as the screws you have.

  8. barbara tetenbaum

    So Paul, the question now is: should I accept a newly-cast set of rollers that have a flat spot, or should I go ahead and start using them and hope that this somehow works itself out? I haven’t measured the entire roller, but I wonder if they were sitting in the shop, laying on one side, if this would be enough to distort them….temporarily, I hope??
    I wrote the company about it already and am worried they won’t want to recast as they already had to recast both rollers (they cast them to the wrong end of the cores, even though I carefully marked them).
    Thanks again for you help. It’s great to have this blog!!

  9. Barb

    I too had this unfortunate experience on an SP15. The cause of problem I discovered was the overzealous application of force by the roller guy when torquing the cores onto the lathe for grinding. F*cked up the cores royally, just as you describe that the retaining screws no longer fit, let alone “retained.”

    Who recast the rollers or perhaps a more polite question would be, were they someone you used before or a new roller company? I only mention this as you indicate the rollers are unevenly cast, so . . . could be it was a bad day at the roller company.

  10. Metric screws ?! This makes no sense for an American company that ceased production in 1900 and 76. If true these cores are way after market.

    The SP15 roller diameter is 2.5″ +/- .015.

  11. barbara tetenbaum

    Well, I took the rollers to a machine shop and discovered that although the cores are the same as my other set on the outside, the threads are metric instead of SAE ((??why??)). So I was able to get some metric screws and am using washers to hold everything in place. So far so good, except that it appears my newly cast rollers are unevenly cast…..(insert expletive here)

    So there’s one for the books,

    thanks, barb

  12. The bearing block is held vertically, because of the height adjustment post, the collar (a steel ring with two set screw) would limit the latteral movement of the roller and stabilize the block.

    Fritz is at the
    The American Typecasting Fellowship Conference this weekend in Ohio. He wont be back in Silverton until the end of next week.

    The more I learn the less I know. There must be someone else out there who has experienced this. Eric? Gerald? Dan?

  13. barbara tetenbaum

    Thanks Paul for helping. They are threaded with a slight bevel leading in, and look just like the other set. A friend is wondering if the threads may be a different size. I’m going to try Winks Hardware tomorrow. I wrote Fritz, too. But what do you mean about snugging the nyliner with the collar?? Can you describe how this would keep the block, etc. on?
    Thanks again,
    barb

  14. There were a few engineering changes on the SP15, but I’m not aware of one relating to the core ends. Fritz may be able to tell us. Meanwhile, you should be able to use them as is. If you have roller collars snug then against the nyliners.

    Can you see threads inside the cores or do you see beveled holes? I have a set of Challenge 15MA/MP cores which have threads on one end and a smaller unthreaded, beveled hole on the other end. Each end has a recess for a retaining ring to keep the bearing block on the core. (The threaded end is for the hand wheel featured on the non motorized MA model.)

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