Recently I had a big jam on my Miehle v-50. Some furniture was sticking up but it was not running full speed. Now it won’t go on impression at all. I’ve tried moving the valve inside the cylinder to always go on impression and that doesn’t work either. If i stop the press when the cylinder is going down and move the cylinder forward it will advance but only the once. There must be something broken or bent but I can’t see anything that looks like that. I really hate to junk a press when I’m sure it’s probably just a small thing. I don’t have anyone nearby (Denver CO) who works on any kind of Letterpress. Any help is appreciated.

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A better description of the jam and maybe some pictures would be a help. I’ve run a Vertical for a while but have a hard time picturing what happened to your press. How was the jam cleared? More information is needed.

One or two pieces of furniture were not locked down properly and when the cylinder came down, it jammed against it. We had to use a pry bar under the frame that the cylinder rides on. It runs fine except for not going on impression. I’ll take a picture tomorrow and post it.

Odds are it’s probably fixable. What’s important to know is:

Was the press running under impression when it crashed (guessing it was and the cylinder was in motion).

Pictures of the cylinder and especially where any prying was going on (prying what against what to move where).

The problem my be on the drive side (right side when facing) of the cylinder, and that would require removal of the right side guard which I DO NOT recommed if you have limited mechanical ability and do not understand the mechanics of your press. I don’t know of any mechanics in your area but whatever you do, do not scrap the press over this.

A thought , check your vacuum pipe to the cylinder miss sheet device you may have knocked it off . The machine will not runin print without a relatively good seal on the sheet at the grip of the impression cylinder (the rows of wee holes most bo covered if my memory serves me correctly ).

I agree that it may be fixable, but the pry bar routine sounds dreadful. Some good pictures are still needed.

Second picture is the position it was in when it jammed. The cylinder was on the down stroke and it was not on impression. The first pic shows where we pried it. We went above the ink platen and pushed the bar that runs with the cylinder (sorry, my nomenclature is poor on this thing). It only required a little force to get it unstuck and then we took apart the chase and pulled the pieces out from below. I had the guy who fixes my Ryobis come in and he had the back cover off and it doesn’t seem to be vacuum. We were able to trace good pressure all the way to the cylinder. It seems like a timing thing or a latch that is broke or bent.

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I assume you had the ink rollers in place when this happened and then removed them to pry? I would think this could mess up your ink roller assembly but fail to see how this would affect the cylinder trip mechanism. I would think it is in the air system and there are several places to adjust the air. Make sure you have both vacuum and blast air working as the first thing, then the settings inside the cylinder, at the feed board and gripper bar, the shoe on the right guard, the relief valve at the bottom right of the press, all the air lines, etc. An alternative to the pry bar routine would have been to see if rocking the flywheel back and forth by hand will loosen things up, with the clutch engaged. It sounds like you don’t have a manual or a parts book and that’s a must for this press. Looks like a good machine—don’t trash it.

It is a good press and it will break my heart if I can’t get it to run again. I’m uploading a video to show you what happens. I don’t think it’s an air problem.

Here is a link to the you tube video

I replaced all the air tubing and it’s doing the same thing. Does anyone think it’s possible I jumped a tooth on the cylinder? It seems miss-timed to me.

you wont jump a tooth on both sides at once without bursting the cast carriage , Ive seen one that did that ,if you jumped one side the bed would not run up or down so give the gear jumping a miss they really are too delicate for that to happen without the frame or carriage breaking , i am trying to contact a mate that rebuilds these but as ever he is proving hard to track down .When i owe him he is back with a annswer in hours !!!!

I have only had a little time on these they were not favourites of hse people here so was steered to other machines in my time . You could have bent the lock mechanism between the gear and the stop cylinder but that is a huge guess as i need to look at a manual to be honest just to bring up 20 year old memories although i do have one that is in the garage red withrust !!! I will talk to someone over the weekend and have a look at ours to see what you may have done .

We have revised our guess and don’t think we jumped a tooth. I think it has to do with the timing of the air actuator on the right side of the frame when the cylinder is down. It actuates the diaphragm and it seems like that is not lining up right. We’re going to play with the cam followers on the bottom below the inker. There are adjustments there that might make a difference.

You didnt turn bolts when you smashed it i would advise you look for line up points and sprung pins because if you move things now you will almost certainly need a good man to get things right the more you re adjust at this point the more problems you will create making the fault harder to find !

I would concur: don’t adjust anything that was not in the area where the cylinder jammed. The cam followers at the bottom have no relation to your problem. It is possible that the air acuatator on the right side could have been damaged — or the hose to it cracked (I opened up the right side guard and the hose was as brittle as glass).

To ask a rather obvious question, you are trying to test cylinder function with the feed board in position, and with the vacuum holes plugged off where the stock isn’t running? Another is that when you have the cylinder stopped at the safe zone (as marked on the left cylinder guard, are you able to use the tommy bar to rotate the cylinder all the way around, or does it hang up?

If I had a press handy, I’d be able to offer better advice. Still, it seems that the problem should be fixable. One solution that I have seen (and used) for jams is to hook a large pipe wrench on the rim of the flywheel and move it that way—though there is the risk of breaking the fiber gear, or a shear pin buried down behind the flywheel.

I have unjammed a few in the past we just smashed the furniture up . it can be replaced and you can clean the gear out after. release as many quoins as you can get at and drift the furniture out piece by piece ,have the same process for flatbed cylinders get in there and pick away till you get it all out with as little damage as possible to the machine certainly no crowbars , i can be a bit of a savage in some circumstances but you can do so much harm with a 6ft bar ! I have had the top caps off a cylinder before now that means days of dismantling even knowing i am unable to rebuild what i have done ,that takes a proper pensioner who worked on them in there day to rebuild it but the press survives at the end of it . a cylinder SBB top caps cost more to replace than i can buy a whole machine at auction !
to make a point of horror i have even cut a chase up with an angle grinder while in situ but still no pry bar !

We defeated the air activation so that it should always cycle and it does with the jacket off, but not with the jacket on. Which makes me think it is a mechanical problem involving whatever latching mechanism makes the cylinder rock forward when it completes the down stroke. I’m afraid this press is toast. I have access to a parts press which would probably have the parts I need, but there is no one who can disassemble the cylinder and get it back together and timed right. I appreciate all the help.

If the cylinder won’t turn with the jacket on, have you tried adjusting the vacuum trip screw to see if it will trip then? The fact that the cylinder will stop indicates something is working and the problem is likely in the cylinder air system. The cylinder does stop in the right place, yes?

Also, does the cylinder turn easily without any undue noise (grind or clunk). If the cylinder turns normally when barred over by hand, try to run the cylinder with/without standard tympan and packing and see if the cylinder will turn then.

It could be that the gripper bar is bent, or that the jacket is bent at the lead edge and preventing the gripper bar from seating correctly.

If the gripper bar is not on, the press should not cycle (if the air is set correctly).

Don’t give up on the press yet!

I have a hose running to block the air (see picture) so it should always cycle. Which tells me it’s something besides air if it won’t cycle most of the time. It runs smoothly by hand, but sometimes when it gets to the bottom of the stroke, it will try to advance and it looks like the gears don’t mesh, it makes a loud bump and doesn’t engage. Does anyone know what makes the cylinder engage when the diaphragm engages? That, I think, is the mechanism that is broken or bent.

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mike, I missed this question earlier ,

<<,Another is that when you have the cylinder stopped at the safe zone (as marked on the left cylinder guard, are you able to use the tommy bar to rotate the cylinder all the way around, or does it hang up?>>

It won’t go backwards but I can make it go forwards easily, just like always. But it does hang up on the way back and won’t go around.

I think it would be worth a chat with these guys before you trash the press…they have helped many I know.

Best of luck, -Clay

You cant have killed it if you have an intact press the bill wont be cheap but the replacement of the whole machine will certainly be crippling in comparison . I cant locate my paperwork for this machine but you have only bent something so its not the end of the world .

What happens when you bring the cylinder to the top and unlock the cylinder?

I remember something similar happening to me 20+ years ago and the mechanic unlocking the cylinder and putting it back into proper position.

I’ll check to see if I have any notes in my manual about it.

Good News. After lots of false starts and plenty of help, I have this press running again. So far it only continually on impression, but I think with a bit of finesse, I can get it to feed properly again. At any rate I can die cut with no problems. Thanks for all the comments and help!

the loud noise sounds like your ink table vibrating gear broke a tooth. part #22582
and the other problem sounds like the actuater is missed alined, also there is a screw on the outside
of that brass piece that should be LOOSE,
when the cilinder is down, it should stick out.
i have been training for over 25 years, running for over 35 years. i was trained to trouble shooting, operation, training and repair in many types of letterpress, i run 2 MV v50,
and 4 windmills, and maintain 4 other windmills.
i spend my days with trainnies and have seen my share of jam ups, and loose chases that fall apart during the run. we use a lot of metal furniture and it shows. there are limited parts for MV
presses and have to weld a lot of parts, just as long as it is not the main frame that gets damaged it can be repaired. both the MV and the windmill have there pros and cons, but both serve there purpose.