uneven platen

I have a c & p craftsman,the impression on the platen is harder on the top than the bottom,I do not know how to level it,theres no impression bolts on the platen or anywhere near the platen,I have 1 adjusting lever at the back of my chandler,to give harder pressure it needs to be turned anticlockwise and clockwise for less pressure.There is a lever on the side of the machine by the fly wheel which i don’t know at all what it is for, i’ve tried to turn it but does not solve the problem.It takes me longer to do the makeready than the actual job,please could someone help me?

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chandler,

Underneath your platen, you should have 4 rather large bolts. You can get to two of them when the platen is in the closed position and the other two by reaching from the back of your press. I needed to a REALLY large wrench to turn them. I am no expert at this, but you can load up your chase with type in the four corners, make an impression, and keep making small adustments until the impression is even all the way around.

I hope this helps…

Chandler,

I have a C&P craftsman as well (12”x18” auto - new series).

It sounds like what you’re calling an ‘adjusting lever’ is one of the impression screws - there should be two of them on your machine. One under the ink-disk & the other, as you noted, by the flywheel.

Your instinct is correct that the screw up by the ink disk controls impression at the top - while the screw near the flywheel controls impression at the bottom. But the thing to know is that these screws don’t really function independently. That is, changing the impression at the bottom will usually affect the impression setting at the top & vice versa (to a lesser degree). Also you are actually adjusting the position of the bed/chase/print surface rather than the platen.

It sounds like you might need to back off your top screw & then crank in the bottom - that should help bring your print surface more parallel to your platen. Then you can adjust your impression from there.

If you don’t have a copy there is a PDF of a manual that may apply to your machine on the Boxcar Press Flywheel & Cylinder page (http://www.boxcarpress.com/flywheel/index.html):

http://community.moertel.com/press/cp-automatic-manual.pdf
(Hand Wheel Impression Control - Pages 10 & 11)

It has some good information regarding the non-linear relationship between the two impression screws on the C&P Craftsman.

Hopefully our presses are similar & this helps get you on the right path. -Jason

Thanks for the input guys,my machine is like Jasons though. I now understand how to level the machine,I now
have another problem,after adjusting the inpression screws I now have
hardly any pressure unless I use a thick plate,by the way I do die cutting
& hot foil stamping on my C&P.It was never like that before I could use a
thin plate about 1mm thick.I tried to use a 2mm thick plate the cut got
better but still not right through,that is with the top impression screw
all the way in and the bottom on the middle mark.I tried to adjust the
impression screws in all kinds of ways and did not succeed in getting a
right through cut.On the top adjusting screw there is a silver plate
marked in and out just to the right of the screw ,now on the shaft that
has the arrow on it to show your position whether u moving in or out,
beneath that arrow there is a screw which has something to do with the
teeth on that shaft,what is the purpose of that screw & the teeth on the
shaft?hope u can understand my explination,and also my on and off impression lever is so tight that sometimes I can’t even move it even when the machine is running.Please help me I am despirate now for the help.

Chandler,

I got the message you emailed (similar to above) & took a look at my press when I got home….

Now I think I’m understanding the teeth you are describing. But to be sure we are on the same page - what I see is two collars on the upper shaft (one on the left and one on the right). These each have one ‘tooth’ on them. This ‘tooth’ has a flat face, and the flat on the left vs. the right collar faces the opposite direction.

To be honest I never noticed them there before. But after watching them as the press was action (with the throw-off lever both off & on) & then adjusting the top impression screw to the extents (both in and out) - it seems to me that these might be ‘stops’ you can set (by means of the screw you mentioned) to limit how far you can move the top impression screw in either direction (this would be why the flats on the teeth face opposing directions).

I could be totally wrong here (and a confirmation form someone else would be good). On my press these collars are set beyond the travel of the to impression screw & I really couldn’t say why you would ever need to limit your adjustment.

As far as the die not cutting all the way through, like I mentioned in my email I haven’t done any die-cutting myself but is your die the right height? I assume you run dies type-high (.918”). If you’re using a cutting-jacket (or plate) on your platen to protect it, and it measures 2mm thick (or 0.0787”) I would think a die measuring type high could definitely achieve enough pressure to cut through - of course this assumes the machine itself isn’t worn/sloppy.

With about 0.035” of packing and a type-high print surface my press makes a “kiss” impression right about in middle of the adjustment range (again this might be different with die-cutting).

For the throw-off lever being stiff - as long as you press is well oiled. I’m not sure what to say. Perhaps someone can chime in on this if they have some insight as to a potential problem. On my press I know my lever certainly has spots (along the travel of the rollers from top to bottom) where its harder to move. I’ve just attributed this to the natural mechanics of all the moving pieces this lever is attached to. Sometimes the pieces align in a way where they almost seem to “bind” because your leverage point is in constant transition due to movement of the press.

Hope any of that helps

The size rule I use is a 0.937” rule which is commonly known as a high rule which I think is sufficient enough for the machine to make a cutting impression.What I don’t understand is why cant I get it to cut right through all of a sudden.even with the impression screws turned all the way in it does not work.As for the teeth I was talking about I think were on the same track it seems to me that it does control the limit of the impression screw so I think the problem is solved as for the die cutting I still need help,thanks once again for the help.Should I change the subject of this specific problem or just leave it as uneven platen subject.

I don’t know, you might want to start a new thread if this becomes strictly a die-cutting issue but I did just have one last thought…

I might have missed it before, but your last message indicated this problem came up all of a sudden. This got me thinking - do you imagine your impression problem could be related to your throw off lever sticking?

The way that bottom impression screw adjusts the impression is by means of an eccentric bushing/bearing. I believe the throw-off lever also affects that same bushing/mechanism, rotating it back to a further degree in order to keep the bed away from the platen… the two problems may be tied to each other.

Hopefully that reasoning is valid & wont point you in the wrong direction, but it might be worth investigating.

-Jason

Thats exactly what I thought,maybe the bushing mechanism is the problem to the die cutting not cutting through and throw off lever been so stiff.I was playing with this mechanism yesterday and it seems that it does restrict the top impression screw to specific in and out limits.I think it is time to start investigating this bushing mechanism.I will try to get information about this mechanism,I would really appreciate it if you could help me with this investigation by getting information on your side and I will do my part on my side and see if we can come to a conclution,keep me posted.

Robert

Robert,

I played with the throw-off on my press a little this weekend. I feel confident in my earlier statement that the “throw-off” action on the craftsman is by means of moving the same eccentric bushings that the impression screws control.

In looking at mine, I realized that I had forgot to mention the connecting rod from the bottom shaft to the top shaft that moves the top shafts eccentric bushing when you move the throw off lever, retracting the top of the bed from the platen as well as the bottom (at the same time). The bottom of the bed still looks like it retracts more, but not as drastically as I was thinking or might have made it sound.

My previous comment was that lacking impression may be a symptom of your “throw off” lever problems/stifness. I cant tell you why it would be stiff outside of previously mentioned ideas (oil, mechanical/wear - perhaps dirty). But more to the point it would have to be limited in its range of motion (that is, you cannot move it to the full on/off position) for it to be your problem.

-Jason

Jason,

Okay this is what I figured out,If I use a 3mm plate I can get a right through cut,but what confuses me is that before I could adjust the bed so that I could cut through a piece of paper on a bare platen without using a plate(don’t worry I don’t cut or print without a plate on the platen,it was just a once off test I done,ha!ha!ha!), now for some reason the blades sit about 2mm away from the bare platen on full impression.Also the screw that controls the bushing mechanism is only there to adjust you’re limits to how far in and out you can adjust the pressure,so you were correct in saying that it adjusts the limit of the in and out movement of the impression screw.What I don’t know is does this bushing mechanism affect both impression screws.What do you recommend I try so that I can get that full impression back again.Thanks for the help I really appreciate the input you giving me.I have a big job comming up for this machine and I am starting to get a bit worried if things are going to work out or not.I am going to do hot foil stamping on A4 conference folders onto 200 gram board,this is the only machine I can rely on for this job,so please hold thumbs for me and I will keep you posted on the success,I think we all go through these ups and downs hey?

Robert

Robert,

I think our terminology might be out of sync with each other.

When you say bushing mechanism it sounds like you are describing the two collars on the upper shaft (the “teeth” you originally questioned). If that is indeed what you are referring to - my recommendation is to set these to the furtherest open position (the positions that allow you to adjust your upper impression screw its full range in both directions) & leave them there - these shouldn’t be your problem (as far as I see they only serve to limit the top screws movement).

When I’m talking about the bushing, I am meaning the eccentric bushings inside the main frame/casting of your machine which the upper & lower shaft fit through, you cant really see these directly (there are two on the top shaft & two on the bottom shaft). You can see where the throw-off lever is attached to the bottom one & also a rod connecting that same piece to the upper bushings attachment point. When you move your impression screws these bushings are ultimately what moves - rotating & moving the bed/chase closer or further from the platen (again on both top & bottom shafts) - your throw-off lever also moves these same bushings, just to a further degree.

From what you describe thats my best guess at where the problem is. Sorry to say though, thats as far as my experience goes.

Jason

Jason

Thanks for the help I am comming rite slowely but I will get there you have helped me a tremendous amount and I appreciate it,at least I know how the pressures and bushes ect work.

Thanks Robert