SP-15 won’t trip

I’m having some trouble with my press and I’m wondering if someone out there can help me diagnose the problem. First off, I have a Vandercook SP-15. I purchased it a while ago and just recently got it up and running. I was able to print on it for about 150 impressions when it became difficult to trip, It felt like the trip lever was sticking for a few runs and then it stopped tripping altogether.

Up to that point, the press had been working very well, it gave an excellent impression and it showed no signs of trouble. After it broke, I was able to trip the press, but only by bumping it against the nylon roller that activates the lever much harder than I was comfortable doing.

I looked the press over as best I could and I found a broken trip spring. Assuming this to be the problem, I replaced the offending part. This did not fix the issue. The press felt exactly the same as before I had replaced the broken spring.

I’ve looked at every part that I can see without removing the side plates and everything seems to be intact. I get the impression that the eccentric is sticking for some reason, but I can’t fathom why. I can watch the trip lever mechanism doing what it’s supposed to on both sides, but the eccentric doesn’t seem to want to turn. The nylon roller on the side of the press is fine and everything looks lined up properly.

I already made one attempt to get the side plate off, but it didn’t want to come apart for some reason. I couldn’t tell if it was hanging up on something or if I just had to hit it harder. So, before I go attempting to pull the side plate off again and getting myself into a bigger mess, does anyone have any suggestions of things to check or ideas on what might be broken? If you think I should pull the side plate off, please let me know if there are any common stumbling blocks to doing so that I might have missed the first time through. Thanks for any help you may be able to offer.

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Eric Holub
14 years ago

Earlier this week I was working on an earlier-style SP-15 that ws stuck in “print” and wouldn’t trip. We took the side-plates off (which can only be done with the carriage at the end of the bed with the upper impression roller past the flange between the gear rack and bed bearer) and found that the cylinder eccentric was almost cemented in place by some hard rusty gunk. Not indicative of proper lubrication! On cleaning and reassembly, it would still not trip, though it could be moved by hand, so the far side-plate was removed, cleaned, lubricated and reassembled. Still no trip. It turns out that the cover-plate over the cylinder eccentric must not be completely tightened or you will bind it against the side-plate (or just create resistance). There must be clearance between cover plate and side plate, and then you tighten the set screws so that the screws will not loosen.
Some of you with trip problems may have loosened and then over-tightened the cover-plates.

john christopher
15 years ago

When I had a broken trip spring the press came to halt with the cylinder at an angle with one trip arm in trip position and the other in print – it might be worth checking that both trip arms are in matching positions.

The trip arms make contact with the plunger pins protruding from the bed frame just behind the ink drum – if you switch the trip lever to trip with the cylinder at the feedboard end you should see the plunger pins pop out, and spring back in again if you return the lever to print.

The nylon wheels are part of an automatic sequence which raises the cylinder at the bed end and lowers it again as it returns to the feed board end. Always let the cylinder complete its sequence by taking it to the very end against the bumper springs and back – no short rolling as mentioned before.

It might be worth posting some pictures of the press so that we can see if anything obvious is missing?

Paul Moxon, Moderator
15 years ago

I consulted another older SP15 manual containing Sheet 247, which shows four (!) part with the name “Trip Arm”. X-20804, is the previously mentioned flat bars connecting the plungers and the spring (ARS-5 ) just as Kyle said. X-20510 R.H. (and presumedly L.H.) is also called the Trip Arm, it contacts the end of X-20804 when the Print/Trip level is shifted. Oddly the plunger is not named and no part number is given.

This same manual on Sheet 248 uses the name “Trip Assembly” on the Carriage Side Plate, which is called ‘Trip Arm Assembly” on Sheet 287-A of the new manual.

My apologies to Kyle for any perceived admonishment.

kyle van horn
15 years ago

There are not very many oil holes on the SPs. The most critical for you currently is at the base of the handle, at the top of the plate around the axle for the impression cylinder… I think they were originally painted red, though that could have been worn off/covered up years ago.

It’s a tiny groove at the center top of the eccentric (the off-center circle ring). Oil that, then again, then again, then again. There is a matching one on the other side of the press, right above where the gripper-lever enters the cylinder. That’ll be a good start.

And, in general, if it is a moving metal part next to another, it probably needs oil, regardless of what any manual says.

kyle van horn
15 years ago

Thanks Paul, my copy of the SP15 manual is mostly useless.

Paul Moxon, Moderator
15 years ago

Sheet 282-A from the SP15 manual shows a spring (ARS-5) that regulates the plungers (X-20805), which Eric and Kyle are calling the pins. Unfortunately, no name or part number is given to the bars connecting to the spring and plungers, but they shouldn’t confused with the trip arms linked to the eccentrics inside the carriage sideplate. Not intending to be persnickety, just clarifying for our less informed readers. Well, that and I’m in teaching mode in preparation for my workshop in Iowa next weekend.

kyle van horn
15 years ago

I’ll preface this by saying my knowledge of the SP lines is based on the SP20s, but I think most of this should translate.

If it is not tripping on the downward (away from feedboard) pass, the problem may be with the 2 pins in the body of the press that pop-out when you throw the trip lever. We had an issue on our SP20 where one was sticking and half of the press would remain in print mode while the other lifted to trip.

If the press is not tripping at all, they may need lubrication, or have broken springs, or who knows what. They are accessible under the dead-bar and cover, immediately in front of the drive-roller. They are a very simple mechanism and should be easy to troubleshoot.

ALSO – inspect the Trip Arms, accessible under the cover behind the drive-roller. If you have a loose screw, you may not have the leverage needed to push out the pins.

If it is not tripping on the return pass, after pulling a print, you should inspect the nylon wheels at the foot of the press. Chewed up and mangled nylon is a bad sign. Oily but solid nylon is good.

Good luck.

Eric Holub
15 years ago

The more I try to remember the SPs, I think there are two pair of nylon rollers. The pair at the end of the bed lift the cylinder to trip position when the cylinder gets to the end of the bed. As the cylinder returns to the feedboard, the other set of rollers drop the cylinder to print position, which could be considered the “normal” position. When you move the print/trip lever to trip, the pins extend, and the cylinder is moved to trip position as it moves past.
This unique design is why Gerald Lange has warned against “short-rolling” Vandercooks. On the SPs you can slam the fingers inside the carriage into the nylon rollers when not moving through the complete cycle.
I did look at a SP-25 that had nylon rollers on rather loose studs. See also if the nylon rollers are firmly attached.

Eric Holub
15 years ago

As pointed out in the previous post, has the cylinder eccentric mechanism been properly lubricated? Not with WD-40, but with oil? The oil hole at the top of the eccentric ring is easily overlooked.
You shouldn’t need to take the press apart to see what is happening inside the side plates. Get an extension mirror at the hardware store, and a small bright flashlight or two. With patience you can inspect all the relevant moving parts.
Is the new trip spring installed correctly? I think the cylinder has to be in a specific position, probably print, before you install the spring. Is the spring on the other side intact?
There are nylon rollers on both sides, and I seem to recall a pair at each end. Are all present?

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