Wednesday, March 31, 2010

Determined to get the Most from my Poco!

Hi Group,
I've had my Poco about two years. It took a while to sort out some missing bits (the stops) and get it working smoothly. Boy, it sure does love some lubrication on those gears. I wonder what product everyone likes best for that? My husband thinks I should switch from generic grease to his teflon bicycle chain lubricant.

I got a metal plate the thickness of a galley and the full size of the bed so it's now type high. I'm using Yupo as my tympan--it's durable and wipes clean. So far I've printed some book arts kinds of things with metal type and linoleum blocks and that worked pretty well but I realized registration was a big issue. A friend has a proof press and thinks I should just register on the cylinder but my experiments didn't seem to work. Since it prints from both directions I couldn't just rig up a registration device like a Vandercook would have.

I liked Neil Giroux's idea but didn't have the metal working skills to make that and didn't like the business of hanging it from the ceiling. I'm in a warehouse with a VERY high ceiling and I'm 4'11". After some thought, and looking at any other tympan/friskets I could find, I decided it would be good to have it open across the bed. Hinges need to be small and I thought of those piano hinges I saw at Home Depot. I do some bookmaking and have lots of binder board so I attached a piece to the piano hinge which can then be locked up in with the furniture. One minor drawback is that the piano hinge is a little too short but I can hold it at the right height for the hinge and if I tighten the quoins it will stay at the right height. There are two sizes of piano hinge and I used the narrower one. I make the holes with a Japanese hole punch.

The first prototype was without a frisket. I just cut a hole in the binder board where the type or image was and made registration stops on top of the binder board. I'm printing a wedding invitation right now using a boxcar base and polymer and realized the binder board alone wouldn't be a good idea. So I used some heavy mylar as an underlayer and added it to the hinge instead of making another hinge. It worked but it was a little awkward to use-kind of like opening a two page book. I cut out the print areas from the mylar and put register stops on the binder board.

I'm wondering if I can find a better material than the binder board because it's a little too thick. I like the piano hinge because it is very reliable in that is doesn't shift or wiggle. I use very short flat bolts/nuts. They are sold in the hardware store with a sort of matching sleeve and are what you might use on a photo album and I think it was called a "post". It has a very low profile head and I replaced the sleeve part with the thinnest nut I could find.
One thought I've had would be to use a some kind of sheet metal for the tympan frame/frisket frame with the center cut out so that it would not need corner hardware. I actually wondered if a hinge of duct tape would work. I really like those carbon fiber hinges I saw on the blog. Will the epoxy be strong enough to hold the frame together?
I should mention that my poco was sandblasted by the previous owner and used as a display piece.
Well, that quite enough for one post. I posted on Briar Press (Poco stops and other issues) and if you scroll down there are some more photos.

(Lynn Starun)


  1. Hi,

    So many questions and ideas... To most of your questions, I have to say: "I don't know." But I do like all of your ideas :-)

    I expect a duct-tape hinge would work, for a bit, but it might be hard to keep the registration tight. On mine, the tympan frame fits pretty firmly in the bed, with very little slop. Makes the hinge sort of optional.

    I think the epoxy I used will work fine. The L brackets give lots of surface area for the glue joint and I worked hard to make sure all of the surfaces were clean. Fingers crossed.

    It's possible to get different weights of binder board; perhaps a lighter weight would serve your needs. Or museum mat board?


  2. Also, I doubt it matters what lubricant you use for your gear drive. If your husband is willing to share, great!

    We've got these old monsters, build from cast iron and steel. Been around for many years. Think about how few "miles" we put on them, versus, say, your husband's bicycle.


  3. I like that word"slop" for what I was talking about. Another thing I wish I could improve is the strength it takes to turn the handle. I have had two etching presses and one took real effort to turn and the other is a breeze due to having gears. Probably I have too much pressure for this wedding invitation and that's part of the problem.
    The binder board does come in different weights but it gets too floppy as it gets thinner. Seems to me you want the tympan to stay flat and not too flexible. Is there a reason the tympan has a strong frame? Maybe with flexibility comes some some amount of stretch?
    I want my tympan/frisket to be: easy to use, fast to use, adaptible for varied jobs, cheap, replaceable, cleanable, registratible (new word?) and maybe as icing on the cake to look good. That's not asking too much, is it? I'm very happy with the inking bearers I rigged up with advice from someone's post. I bought the brass bar and then added a layer of strapping tape to raise it just a tiny bit. Since the boxcar base is so wide I used two strips of the leading material taped together with double stick tape and lay is alongside the polymer area. I used some masking tape to make a little tunnel for the leading to slip into which keeps the piece from lifting out of place due to the tackiness of the ink. I made the strip long enough to project over the edge of the base so it stays clean for handling. Boy, telling all this makes me realize I have made progress but I keep focusing on the next problem area.

  4. To achieve good registration, the tympan needs to hold things in place, repeatably. I use a polyester cloth stretched tight; other folks use paper, silk, etc. The tympan frame needs to be strong enough & rigid enough to support the tympan when it is stretched. So far, I've not replaced my tympan.

    The frisket doesn't need the same degree of rigidity; it only serves to lift the paper off the type. There's no reason to make it from the same material. I use paper held in place with masking tape and replace it often, almost every new job.

    To reduce the effort, change the packing. Trying to achieve a deep impression with hard packing mean you'll have to pull hard! If you want to keep the deep impression, try a softer packing.

    I don't really understand your description of your roller bearers. Maybe some pictures?