Poco stops and other issues

I’ve just acquired a Poco #0 proof press and today I got it cleaned up pretty well. I was told this press was sand blasted at some time in the past and used as a display object for many years.

The most urgent issue is that there is nothing to stop the bed in either direction. I’m hoping some Poco owner can clear up the mystery of all the little holes and the little rod that protrudes at the end of the gear side of the bed but which doesn’t seem to act as a stop. I sure don’t want the bed taking a dive off the table!! There are two holes on either end of the bed that look possible as stops with maybe a rod in them but they stop the bed sooner than I’d like.

The other issue is the device that holds the tympan on the cylinder. It looks like you insert the tympan into the slot but what holds it there? There’s a little pawl and hook at one end but all it does is keep the slotted rod from turning.

Does anyone know where on the internet that you can get a really good look at a Poco that’s operational?

Thanks for any help anyone can give me!!!

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Where are you????????

The “stops” for the bed are located underneath it. I’ll go home tonight and look at mine and see if I can give you a more detailed description.

Yes, the tympan paper goes into the slot and then the bar is turned to tighten it. There are TWO pawls on the gear end, to prevent the bar from slipping in either direction. The screw holding them should be tightened when the tympan is set. (Also untightened to lossen them for changing the tympan. The tympan paper also needs to be cut with miters on all corners so it will fit into the slot.

More later when I getr into the shop this evening and look at everything first-hand.

Sorry it took so long to get back to this. I had to check an old ATF catalog to figure out which model Poco I actually have. Mine is a No. 2 which is substantially different from your No. 0. Mine has very evident spring-loaded stops, to stop the bed in both directions. It is a simple matter of loosening and removing a bolt and taking off the stop to be able to get the bed off of the press. With the stops in place however, the bed will not slide off the press. I remember once trying to help load a No. 0 and was telling someone that the bed should come off fairly easily. When we both looked at the press it was NOT evident how to accomplish that on a No. 0 as I recall.

You may also have only one pawl on your tympan stretcher, and not two (like my No. 2 has). Your press is about half the size of mine.

Sorry I couldn’t be of more help.

If you let us know where you are geographically located, maybe someone close-by can help you out.

Congratulations on finding a Poco No.0 Proof Press.

The whole stopping process is based on 3 pins or rods. One pin on each end and one centered above the rail inside the press frame.

The following is a rambling explanation for a simple problem. I had the same situation and it took a while to figure it out.

There is a hole at each end of the cast iron bed - on the front vertical edge below the gear bar. A small round steel pin or rod is inserted into the hole to stop the bed. The original rods have a flat edge ground halfway through the part that sticks out of the hole. The flat edge of the rod faces ‘down’ so it can slide just barely over the rail attached to the outside frame of the press. If the flat edge is in wrong way or slightly twisted, the bed will stop short when the rod hits the end of the frame. You can test if this is your problem by just pulling the pin out or use pliers to gently turn the round side up and the flat edge facing down (horizontal), so it can slide over the frame. Gently tap them back into the hole. ‘Gently’ is the key word, because it is cast iron.

There is another stopping rod or pin centered inside the frame – not the bed. The bed stops moving when either end pin bumps into the center point. If the bed doesn’t stop, the center pin may be missing. Use a flashlight to find it. It is hard to see the hole in the frame and may be filled up with grease or dirt. It should be right below the center of cylinder press. That hole holds the center-stopping pin. If it is missing, purchase the same size steel drill rod as the end pins at a local hardware store and cut off a small replacement. The end rods could also be replaced if missing. I am happy to help you or even make a replacement piece if one is missing.

Thanks Everyone!
I so appreciate all the tips and instructions in the posts and also from the people who emailed me directly. There seem to be several ideas of how to go about stopping the bed and I’ve been at the Inaugural reading all my emails on a phone without having the press to check things against. I feel like I now have enough ideas to keep me busy and then I may have to consult the oracle again! I’m even more excited and optimistic about what this press can do with a little ingenuity. When I get it worked out, I’ll photograph and post what I ended up doing and how well it works.

Hi Again,
I forgot to answer the question about where I am—New Jersey, west of NYC. Summit, NJ

Thought I’d give a progress report. I’ve listened to all the advice, some of which was conflicting and made some conclusions. Jeff Harp told me that there is supposed to be a piece of rod material which projects from the main body of the press directly under the arm. This keeps the bed from rolling off the press by bumping up against similar projecting rod bits at either end of the side of the bed. On my press only one of these three rods existed. The rod for the side of the press goes through a hole that can be accessed from the outside of the side of the press so we got a bolt and a couple of nuts and cleaned out the hole which was full of gunk. I inserted the bolt from the outside and with difficulty (helps to be a female with small hands!) attached the two nuts onto the end of the bolt where it emerged through the press side. The nuts will keep the bolt from coming out and also thicken the 1/4” bolt to something thicker and stronger. We are still working on the missing rod in the side end—it’s about 5/16ths thick but a rod 5/16” thick won’t quite go in and anything smaller is too loose. We got two cut rings (?)—one too big and one too small and will either force the bigger one in or epoxy the smaller one in or maybe go back to the rod and sand it down to fit. So that takes care of stopping the bed.

The mysterious holes at the ends of the bed are for locking up against, so I got four 2” bolts 1/4” thick and four or five nuts for each. I plan to put three or four nuts on up against the head of the bolt and then insert the bolts downward into the bed and add another nut underneath the bed to hold it in place. It needs to be short enough to clear the various structures under the press. 2 1/2” was too long. Then I put a long piece of furniture up against it and it was like a stop bar or whatever it’s called! The cylinder is a work in progress. Rather than figure out the mechanism I just used bulldog clips to attach first some lighter weight binder board used for bookbinding (grain short—runnning across) and cut it to fit and clipped it onto the cylinder and over that layer I used a thin rubber material. This with a few layers of the usual card stock type packing laid over my form worked very well. I printed a linoleum block under which I put one layer of card and some type which I put just on the bed of the press. I put lots of furniture inexpertly around and quoins and it printed pretty well!! Haven’t worked out how I want to register yet. For this project I just eyeballed it. So, that’s it so far. Pictures will follow. Thanks to everyone who got me this far this fast!

This discussion finally built a hot enough fire under me to get me to move my poor abused Poco #0 indoors and get to work on cleaning it up. I can shed a little light on the two questions. One has already been answered — there are two pins on the side of the bed below the rack gear, one at each end. They stick out about 1/4 inch, and they are stopped by a third pin in the center under the cylinder bearing. I suspect they are probably tapered pins driven into the holes, though they may be threaded.

Second issue is a bit different. The slotted rod in the gap of the cylinder is indeed for the tympan. The two ends of the tympan, cut aslant to narrow them, are inserted into the slot from opposite sides with a little slack. There should be a pin tool about 4 inches long with a loop on one end; it inserts into the holes on the end opposite the pawl, and the rod is turned counterclockwise facing the pawl to tighten both tympan ends simultaneously. You need to leave enough slack in the tympan to make at least 3/4 of a turn of the slotted rod so the friction of the tympan against itself prevents it from slipping out of the slot.

I can report that my Poco’s parts are all freed up from the rust it had, and now I need to clean it up and start proofing!

Hi Poco owners,
I am attaching a photo to show how I attached some material to the cylinder. After some investigation I discovered that my slotted rod is rusted and will NOT turn. I’m giving it an overnight soak in solvent stuff but I’m not hopeful. Also I only have one pawl and someone said I should have two. Since I managed to print successfully with only bulldog clips holding my packing, the lazy me is thinking maybe this is fine. I’ve changed to binder clips with the little metal handle removed on the outside—see the photo. Since I’m printing linoleum blocks as well as type I want a softer material on the cylinder. At this point I have a layer of the thinner davey board/binders board which I had to use with the grain going across the cylinder and not with the cylinder. On top of that I have some fairly firm rubber material. I can’t remember where I got it or what it is but it fit so well and seemed to work well. I will experiment with other things but I do need to build up the cylinder so it will make contact with the form. Then I put a piece of that red hard cardstock and one layer of lettra paper. That worked very well. Had to build up the linoleum to match the type height using a piece of cardstock.

image: IMG_2434.jpg


Here’s a photo of the 2” by 1/4” bolt with nuts that I used in each hole at the ends of the bed so that I can lock up against them. They are just short enough to clear the structures underneath the press.

image: IMG_2420.jpg


This is my stripped bare Poco when we picked it up.

image: Picture 33.jpg

Picture 33.jpg

I hope you can see how the bolt with two nuts attached on the interior side of the press body forms the center stop when the projecting plugs from either end of the press bed run into it. I think I will need to file one side of the metal plug/rod flat so it won’t scrape against the body of the press. Jeff pointed out that the hole is tapered so making this piece will take some care. The other one is intact on my press.
One other problem I’ve noticed is that one of the roller bearings under the bed tends to migrate inward and when it does it won’t turn easily. The bed has no problem moving but maybe the bearing should turn so it doesn’t get worn away? I’ve cleaned the heck out of it but so far only gotten it to turn but not to turn easily.

image: IMG_2430.jpg


Here is a sort of mock up for a method of registration I’ve thought of. I laid some strips of cardstock over the furniture till they were level with the challenge high speed quoins. Then I would use double stick tape to attach a mattboard corner snugged up against the block of linoleum . Then my plan would be to cut a piece of acetate the size of my paper and place it on the form and figure out where the paper should lie. Then I would use double stick tape and attach a second mattboard corner to determine the exact place for the corner of the paper. In the picture you can see a clear piece of plastic over that corner which would be glued onto it. So that would hold the corner of the paper and then I would have a similar construction that would be straight along one side to guide the side of the paper. I haven’t tested this out yet. Maybe a bit of low tack tape would be helpful to make sure the paper doesn’t shift.

image: IMG_2419.jpg


Lynn, try oiling both ends of the slotted rod and then stick a rod into the holes on the left side and work it back and forth gently. If you can get it to move it will come free as the oil works into the joints. On the pawl, there is only one on mine and no provision for a second, and a second isn’t needed. When you slip both ends of the tympan into the slot from opposite directions and turn the rod counterclockwise, holding the pawl against the spline, it will lock just fine. Does your press have the rod with a loop end about 1/8 inch in diameter? That’s for tightening the slotted rod to tension the tympan. There’s a hole in the top of the frame to the right of the crank that’s for storing it.

Thanks AdLibPress,
I couldn’t believe how stuck that thing is. I was afraid I might break my screwdriver if I put any more force. Maybe if it sits with the solvent oil in it for a while I can try again. So you think it’s important to get the tympan on there the right way? I don’t have any tympan paper that large but I’ve heard of using mylar. I have that available but since I went to Letterpress Things recently, I can’t make another trip anytime soon to get real tympan! I understand a proper tympan on a Vandercook or a platen where you are putting the paper on the cylinder or the platen. Why would it be important here? Does it keep the packing nice and smooth? Do you use any packing material over the form? I laid a combination of thin cards, I think the red one and a layer of soft thickish paper to add the right amount of pressure. Is that cheating? I’ve done a lot of printmaking so I may have been thinking in a printmaking mode. Maybe if I get a press bed liner I wouldn’t need to do that. Metal would be difficult and expensive so I wonder if I could use plexiglas? or would that be too brittle?

Well, I thought I’d report that I did get the slotted rod unstuck and now it works great. Multiple applications of penetrating oil solvent stuff did the trick as well as finding the right size metal rod to put into the hole. I gradually rocked it loose. Then I inserted the tympan ends into the slot on the same side as the instructions for the Poco say to do. Oh, I haven’t mentioned those instructions. If you go to Flickr and do a search for Poco you will find photos of instructions stuck onto a Poco cylinder. I did my best to transcribe them but several areas were illegible. Here’s what I think it says:
Warning: Insert both ends of tympan in same side of slot

Operating Instructions for the

(a) There is a single slotted reel rod into which both ends of tympan are inserted. Be sure to insert both ends of tympan in same side of reel rod.

(b) Have the slot vertical and the crank ??? when placing tympan

(c) Turn reel-rod to the left with pin wrench, bracing the crank handle
against the body. Ends of typan will slip for 3/4 of a turn and then
bind and lock.

(d) The proper size of tympan is 28 inches long by 12 inches wide with
corners cut off 4 inches down the side and 3 inches across.

(e) For 24 cents in stamps we will mail 12 tympans cut to correct size in a
tube post paid. Tympans must be of right shape and size to operate

(f) In replacing an old tympan, take care to crease the curl out of the ends to
facilitate insertion in reel rod.

(g) Keep the tympan tight. It stretches under use.

2. HOW TO HANDLE PACKING: First wrap all the packing except tympan
into a tight roll so that it will conform to the cylinder; then with the bed centered, place all the packing on the bed in proper sequence with tympan below; then leaving the tympan lie, wrap all the rest into position on cylinder with the two hands; hold into place with the left hand spanning the cylinder opening; while the right hand brings the right end of tympan into position ; insert tympan in the reel rod slot with the aid of both thumbs while the fingers hold packing on both sides from slipping; then span cylinder opening with the right hand and bring the other end of tympan into place with the left hand; insert packing
in same side of slot aided by the thumbs as before holding?? both sides in
place with left hand while the right tightens reel rod.

3. WHAT KINDS OF PACKING: Press is shipped with packing suitable for mixed type and half tone ??????? although the cuts should always be underlaid with 2 or 3 papers. When the proving results tobd (runs to?) remove some press board and substitute papers. This will also make? press operate easier under impression. Always have at least one press board under tympan.

4. WHAT TO OIL: At each end of cylinder shaft and roller shaft is an oil hole, 8 in all, which should be occasionally filled.

5. WHY THE STOP PINS IN BED: At each end of bed are two pins against which a piece of furniture may be placed. These pins may be driven out from below with the reel rod pin wrench when it is found more convenient to slide a galley, or matter from a galley to bed of press.

6. WHY THE GALLEY PLATE: The galley plate is .050 inches thick, which is the standard of American galleys. Cuts and forms placed on the galley plate are the proper height. Galley plate can be removed and galley of matter placed directly on the bed. If this shows a light impression, the galley is thin and should be underlaid with paper. Forms 12 inches and less laid in galleys larger than 12 3/4 inches outside can be slid onto galley plate by pacing galley plate a bit beyond the ends of bed bearers and returned in the same way.

7. SET PRESS LEVEL so that the cylinder runs free. When bed is in center position it should rock slightly on center rollers, which are higher than end rollers If not found this way, and if bed strikes on the end rollers, the frame is twisted by not setting level. Experiment by wedging under each foot (one at a time) until the bed runs free and rocks on center rollers.

8. HOW TO FEED PAPER AROUND CYLINDER: The left end of tympan goes under reel rod when taut, and acts as a gripper for feeding sheet around the cylinder. This can only be done when proving from the right side. Place paper on top of cylinder and with both hands feed the right edge around and wedge it under the reel rod. Hold loose end of sheet against cylinder with right hand while the left hand operates the crank. This method of proving gives the cleanest possible proofs.

9.HOW TO CRANK THE PRESS: To get a steady, constant printing speed when using a hard impression move bed toward cylinder until just before the form print?? and then if proving from the right side push handle with the left hand, bracing with the right hand on crank cylinder shaft, using a short rotating body movement. If proving from the left side, push handle with the right hand, bracing the left hand on crank at the bearing? , using a short rotating body movement. Pushing gives more slow power than pulling. Do not work so fast that the form slides.


A. Use good ink if you want good ???. Don’t expect a $5.00 proof from 25 cent ink.

B. The less ink the better. Reduce amount of ink on slab until it is not tacky.

C. Wash cuts off before proving.

D. Use hard packing and hard impression for half tones and solids; use medium soft packing and lighter impression for type and line cuts.

E. For quick work lay proof paper on the form. For best results feed paper around cylinder. If proof paper is too short to be gripped under reel rod lay it on the form until the front edge is caught under impression, then hold loose end of sheet against cylinder and operate as per instructions No. 8 and No. 9 This not only gives a clean proof but will avoid wrinkling of the paper with an open or ruled form.

F. Use a good firm roller free from flaws. It takes a good roller to distribute ink properly.

G. If you prove the paper flat on the form, steady it against smutting while being placed by holding one corner down first with a finger on a type high bearer or inverted cut placed along side after inking After impression curl the proof slowly from the form holding one corner firmly down as above.

H. Use type high bearers when inking cuts so that the edges of roller are on the bearers. This avoids too much ink on the outlines.

I. Use type hight bearers around cuts while taking impression. This avoids guttering and too much impression on edges of cut.

J. Apply the ink roller to the form as lightly as possible consistent with uniform distribution.

K. When proving type-forms which tend to wrinkle the proof, make packing harder with pressboard, use as heavy proof paper as permissible, reduce impression, and use more ink. The same result can be obtained by laying a piece of pressboard flat on top of proof sheet on form.

L. This is a practical machine: consult your pressman in case of trouble.

?????CE HACKER & COMPANY, Manufacturers, 312 North May Street, Chicago, Illinois


I forgot to say in the last post that thanks are due to Arie Koelewyn for photographing his Poco instructions so all Poco owners can benefit!

Lynn, thanks for posting those instructions — my Poco didn’t have them, so my directions for inserting the tympan into the slotted rod were what I tried and made work. Glad to hear you got yours freed up. I have a piece of red plastic sheet I think is mylar tympan from my defunct Vandercook that I put on the Poco with an offset press blanket from my A.B. Dick 360 for packing. I had ordered a piece of .010 mylar before I found the red stuff in an out of the way storage spot. I got a nice 12x18 galley (from Arie — I think he had another spare) to use instead of a bed plate. The essential bit is that it’s important to have the packed surface of the tympan even with the cylinder bearers to avoid the tendency for the paper to creep and slur the ink.

Ad Lib….. a non-compressible blanket from an AB DICK 360 makes excellent packing for a Poco. We’ve used that for quite a few years without complaint. A compressible blanket also works, but not as good.

My Poco has a printed label located under the ink plate. Here is how it reads:


1. If press does not work freely turn screws in feet up or down as required until bed moves easy.

2. Oil rollers under bed. No oil necessary in cylinder shaft ball bearings.

3. Note how tympan is inserted in reel rod so you can put on a new one properly.

a. Additional tympans cut to proper size, prices on application.

b. Additional rubber blankets cut to size, prices on application.

Hacker Manufacturing Company
312 North May Street Chicago, Illinois

Thanks for all the new information, everyone. This posting list will be a good resource for Poco owners, new and maybe even old!! I had no idea there were adjusting screws on the feet but it’s logical. I wonder if adjusting the feet could compensate for not using a galley or metal plate on the press bed? I’m thinking theoretically since I haven’t yet gone to my studio to look at it.

The adjusting screws on the feet of the press are there to level the press and have nothing to do with distance of the press bed to the cylinder. A level press operates much more smoothly.

Well, more progress has been made—I got a base plate the size of my bed and the exact thickness of a galley tray from the Metal Supermarket and it was so cheap. Now I feel like things are really going to work well. With the bed the right height I can work systematically on the cylinder packing. How can I get this non-compressible blanket? I looked at the website and was overwhelmed with all the choices. My tympan which is made of mylar right now was slipping. I took it off and found some oil had gotten on the ends so I cleaned it and retightened it and so far it’s staying put.

I bought a Poco #0 recently and started a little site about it - see http://sites.google.com/site/pocoproofpress/home

While I was cleaning it up, I found some instructions pasted on the side, but obscured with a layer or two of old paint. They weren’t the same as those reproduced above; in particular, they contained the word “eccentrics”. I expect they refered to how I might adjust the axles supporting the casters (which are machined off center, allowing me to raise and lower the bed by rotating the axles, perhaps an innovation on later models of the press).

Does anybody have any clues?



Some of the instructions above came from my Poco #0; the photos the text is based on can be found here: http://www.flickr.com/photos/95217303@N00/3265696336/
There’re 7 photos in all, that’s the first.

I either can’t remember or haven’t yet found where the serial number hides out. Where’d you find yours?


Arie, thanks for the photos.
The serial number on my press is located on top of one of the bed rails, near the end, just adjacent to the gear track.


image: zap1.jpg


Hmm. Nothing to be seen on the two possible spots this could be on my press. I suppose I’ll have to clean it up thoroughly to be sure, but possibly older ones didn’t have a serial number. Or it is hidden elsewhere. The cylinder on mine does have six spokes rather than the four yours has.

Your serial number is interesting as my Vandercook #1 (a similar press to the Poco except the cylinder moves rather than the bed—the function is the same, a simple galley proof press) has serial number 2205. It was made on March 25, 1925. I think Vandercook owned Hacker by then, Wonder if they were still making Poco presses then.

Interesting. At least some of the older ones have serial numbers somewhere as people quote them.

Paul Moxon suggests on his Vandercook websight that Vandercook bought Hacker in 1937.


I bought a Poco no.0 almost 2 years ago, and have been using it the way it came to me (which is filthy and with very old packing) since I did not have the means to fix it up.
I have now bought a brass bed plate for it, bearers (thanks to Preston’s blog, I used the removable ones suggested), and going tomorrow to buy bolts to use as taper pins until I can send my partner back to the States to buy proper #5 pins.
I live in Bangkok currently, so have nowhere to take it outside to clean it up.

I am wondering if leaving the 100 years of gunk on the press will cause any problems?

Also, I cannot seem to find any screws in the legs of the press to adjust the height/tension. The bed rolls okay, with a slight stick to one end, but does not teeter when the bed is centered on the press, like I have heard it should.

I also believe that the packing under the tympan is too much, since I need very little packing underneath the blocks to print without a galley tray.
It appears that there is 2 sheets of the red press board and 5 sheets of light-weight tan paper (maybe bond paper?)

I also cannot find any serial number and my press no longer has the red Poco seal on the front under the crank wheel. There is a mat black paint on it that is quite chipped, and I am wondering if perhaps it was refinished at some point with the seal never put back on.

I have appreciated all of these posts and trouble shooting tips while I sent some quality time cleaning her up and trying to achieve a higher quality print, since I have moved away from the host of presses I used to have access to at the Minnesota Center for Book Arts & Hamilton.

I have a whole bunch of the #5 pins for the Poco bed. If you are willing to pay the shipping, I’d be happy to send you four of them.

Daniel Morris
The Arm Letterpress
Brooklyn, NY

I just was inspired by this thread to look at my Poco #0 for comparison. Mine has a rectangular metal tag riveted on below the crank, which says “Poco Proof Press/Patent Applied For/Manufactured in Chicago U.S.A. by/Horace Hacker & Co.”. The support rollers for the bed are on rotating axles that are not adjustable for height. The serial number is E1288 and the cylinder has 6 spokes. I wonder what the letters in front of the serial numbers indicate?


I guess leaving old gunk in place won’t hurt anything, as long as it doesn’t get onto your paper. I think most of us clean up the old gunk so we can repaint and have the press looking sharp. On the other hand, you’ll want the bed and cylinder quite clean so the type sits perfectly flat and no lumps disturb the packing.

You can certainly experiment with more or less packing. Probably worth the trouble to start afresh, since ancient packing often has dents. I used 12” x 18” sheets of mylar, but other things will work. Prefer incompressible.

I’d take off the old packing, keeping the old sheet of tympan material (the long sheet that wraps around the cylinder and all the packing) for reference. Then clean up the cylinder as best your can. Then start adding packing, perhaps 1 sheet at a time, very tediously. Try it with the galley plate, some type, and several sheets of paper. Maybe a sheet of carbon paper to help shown the impression. Keep adding packing until you get an impression.

Maybe save some time by seeing how much packing you can fit between the type and the cylinder, sort of like a feeler gauge. But always start light when actually cranking it through, so you don’t break anything.


Every machine I own still has almost all the original gunk that came with 100 years of use, like Preston says just clean the bed and cylinder and anywhere the paper goes.

If you have access to a set of automotive leaf feeler gauges and an inside/outside type-high gauge, you could remove all the packing, set the type-high gauge on the clean bed with bed plate in place, run it under the cylinder, and measure the gap with the feeler gauges until you get a snug fit with a combination of the leaves of the gauge, then add their thicknesses and you know exactly how much packing you need for a kiss impression. If you also have access to a micrometer you can mic the tympan and packing sheets to build up to that thickness.

The scientific method.


Bob’s point about the scientific method is right on. If you’re going to use a tympan and frisket, be sure to allow for them in your reckoning.