SP-15 Trip issue

We have an SP-15 that has suddenly stopped working in TRIP mode. The mechanism that allows the cyinder to put itself in trip is not working and the cylinder stops about 1/2 crank. Print is ok. Most advice I have received seems to point to broken springs, but the springs look like they are intact, at least from what little we can see. My understanding is that removing the side panels to get to the trip mechanism is rather difficult and tricky. Any other SP-15 owners have this issue? Any other possible diagnoses? Has anyone had to disassemble the trip panels? What causes these springs to fail? Wear and tear? Thanks.

image: SP-15 spring.jpg

SP-15 spring.jpg

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If You are concerned about accessing the working parts of the switch gear, with a small can of W.D. 40 or similar (normally comes with very fine bore extension tube) just spray the entire cover from about 6” sufficient %age will permeate the innards inc. springs, rockers, crescents, bolts etc., etc., Although W.D. evaporates up to a point usually leaves a minute oily residue behind. No bad result.!

Maybe the bolts connecting the various levers-bars inside have got too loose….or worn and levers are catching on worn parts….you may have to scrabble around”inside” so to speak…

Make sure that the little plungers that pop in and out of the cabinet when the trip lever is switched are moving freely. I have seen those get gummed up on SP-15s pretty often.

Also check that the white nylon wheels that actuate the trip mechanism (front and back of the cabinet at both ends of the press) are in good condition. And, as Mick says, a liberal soaking with WD-40 can be helpful.

There are oiling points at the top of the outer rings on the front and back of the carriage that rotate when the press goes between trip and print. Make sure those are very well oiled and moving freely. You may find that the press is only tripping at the front or the back, but you obviously need both!


Thanks to all. We tried a good shot of WD 40 first thing. As for oiling, the press is oiled and cleaned on a weekly basis, and the fact that this happened so suddenly, leads me to suspect that lubrication is not the issue. The retractable “buttons” that pop in and out in trip v. print are moving freely, as are the nylon covered bearings, so that is not the issue, either. Am I missing something?

Katie, a few more just shots in the dark or >flying blind< Your retractable buttons as stated are working O.K. but are usually out of sight connected to tiny solenoids and A.C. (alternating Current) is notorious for working the connectors loose even on low voltage, 12 - 24 volts for switch panels (for operator safety) - Even with serrated and brass washers involved, over time and use still work loose, not too high tech to ascertain, i.e. with the mains electricity supply OFF/ISOLATED simple circuit tests even WITHOUT the technical schematics available, generally the wiring within the circuits are colour coded (schematic often found under the Panel/Cover)

The tests:- 6 volt Flashlight/Lantern battery pair of wires with minature crocodile clips and appropriate bulb & holder attached, circuit tests Ad Infinitum, with special attention to Closed or Open limit switches* which themselves are not infallible, i.e. very delicate action triggered via a minute PLASTIC jockey wheel working on an equally delicate return spring, these limit switches usually in the form of permanently OFF unless triggered ON -or- Vice versa permanently ON unless triggered OFF.

Could this perhaps be the symptoms with Your cylinder stopping mid cycle.!
Perhaps mark the exact position it stops and ascertain if the position is precisely the same, each cycle.,?

As Daniel implies (above Thank You) is the stop point synonymous with a complete revolution of the cylinder or a complete revolution of any actuating ring/mechanism.

Re broken spring, in Your pictured shot that spring appears intact, but in the case of a strong spring acting on steel block/buffer (and often without regular lubrication) the Plunger tends to wear away inside the Barrel and gives rise to binding or rough action, published on B.P. recently Slow Motion shots or stop frame can help.
Re the nylon covered bearings, usually a foolproof system, but even nylon becomes dry and occasionally binds, easily eliminated, simple as a minute dusting of Graphite Powder or if all else is unobtainable simple as a minute scrape (Exacto or similar) from standard pencil lead.!

The above offered in good faith, as pointers only, Apologies for potential rubbish. - Good Luck. Mick. - U.K.

Thanks, Mick. As far as I know the trip mechanism is not electrical at all, but all mechanical. Am I missing something?

For all, the binding happens at the same time, everytime, when the handle is at the down position, about 3 inches from home. (See photo). I have a video of this press along with a video of the one that is working, but I think you have to email me offlist to see it.

The other possible clue is that while the cylinder will not move forward in trip, it will in PRINT, and it will switch back to trip normally at the end of the bed, and will go back home in trip without a hitch, as per normal, where it is put into print again, as per normal. If we then put it into trip (from home) it will not move past the point you see here.

image: Vandy Stops Here.jpg

Vandy Stops Here.jpg

Katie, apologies for my humble and possibility misleading efforts, but in line with my pathetic efforts, as You state that the whole >shooting match< is mechanical I believe that the Drive Motor is situate in the base and hangs down under the cylinder and drives through a *Worm wheel drive* mechanism, is it possible to ascertain visually (with NO power involved) IF the drive mechanism is secure on its mounting(s) ? A lot of torque and power has to be transferred through such mechanism(s)

If You are able to look up Worm wheel drive W W W etc. You can see that it is a less than efficient method, i.e. the *Worm* is trying to drive the *Gear* in a fairly crude manner, by implication, secure fitting is a must.
Often involving a large motor & drive, using only 3 Comparatively small bolts around a small flange fitting.

Is the Gripper mechanism, operated by the Foot Pedal pictured, (possibly) with loose or insecure rod operation.? i.e. tripping IN but not tripping OUT completely or short of the cycle.
Re the tiny black knob control lever pictured, (usually linked to a remote, internal rod,) maybe appearing to work on the surface, with safety, ascertain IF it is functioning internally, generally such rod mechanism are *keyed* with either Roll Pins or Taper Pins, both almost infallible, but not always & forever, ??

Apologies if the above is irrelevant rubbish, but may help for elimination.

Perhaps disregard my crude efforts, there is much Good info *On Line* regarding Your press.

Regards Mick.

The press can be operated with out power. Did you check the cylinder check on the far side of the press that engages the front ink roller on impression? It is spring loaded and can break or the spring can break. Or both.

The press under discussion is one that is hand-cranked. There is power, but that only turns the inking drum.

John Henry

Stet. !

J. H. Thank You Sir. I am always more than happy to be corrected regarding my Ill informed efforts. At the end of the day everybody learns including myself.
Thanks again Mick.