Taping the rails

it might be referable to get the rails taken off to an even height both sides then the engineer build up to correct depth.

Hi,

What make & model of press? Can you upload some pictures of the bed and rails?

If you print from adhesive backed photopolymer plates you can also use strips cut off the edge of the plate as bearer tape. I always have old plates around the shop and this is easier for me that ordering the UHMW from Fritz.

DGM

So Simple, but perhaps Too Simple!!! With judicious use of Roller Guage or large piece of type, Metal or wood, matters not, build up the rails, progressively, to accomodate irregularities top to bottom (and left to right) I.E. as in packing up a plate or block to give all over impression!!! Using strips of litho plate (or even Bean Can) exactly width of rails, as a laminate with strips at say 7 5 3 1 inch increments, to build track up to acceptable parallel bed to track!!! And Left and Right, compatible? Step 2 construct simple stainless steel slipper, with right angle, to act as new, accurate, rail and attach, (with laminated underlay) to machine with chemical metal, super glue, or even tiny grub screws at sides, etc. (IN ESSENCE just sophisticated high(er) Tech Option to, say, forever sticking bits of tape on !!!) If the eventual overall height should be a few thou too high and carry the rollers too high, it isnt exactly rocket science to underlay the forme up to precise height. This principle would have been 2nd or 3rd grade, metal work students (Girls and Boys 12-13 years old) capabilities.>>If the rails are an integral part of the bed, Here in U.K. (and providing the bed was removable) we would have it *metal sprayed* up and *ground* back to an acceptable height, But (I) would specify plus, say, 5 thou overall height, from standard???>>Give it a little thought!!!

That is a brilliant addition to the collective toolbox.
I only use metal-backed plates but I know that the film-back plates are much more stable and true than tapes, especially since most tapes can be stretched and therefore thinned during application.
For a quick fix, one could try plastic steel epoxy to level out ripples in the tracks before applying tape, or using a jig and carborundum stone for absolute levelling.

The 1.88mm translates to .074” and that’s a lot of wear. The UHMW tape we sell is a hard plastic that has exceptional wear characteristics and does not stretch or compress and has an excellent adhesive. It does not need to be applied to the entire bed rail from top to bottom, but only in the corresponding image area of the chase and then in shingled layers for an easy transition of the roller trucks. A roller setting gauge will help in making each end of the roller the same distance from the bed to the roller, but final setting should be done using the base and plate combination that will be used. These are often higher, sometimes lower than .918”. Don’t assume that all plate and base combinations work out to be exactly .918”.
I suggest starting with the .010” tape and build up each side to a point where the thinner .005” tape can finesse the final setting. Since plate size and image area can affect the setting of the rollers depending on the amount of ink that is needed, I suggest setting the rollers so that they just barely ink the image area and then adjust the printing height with underlayment between the plate base and press bed, taking into account the packing on the platen. This eliminates adding and subtracting tape layers as the work being printed changes.

The use of electrical, masking, painter’s, and other kinds of tape leads to failed adhesive, corrugated tape surfaces, inaccurate thickness of tape, etc. Metal type is far more forgiving in inking compared to photopolymer plates and almost by definition by reason of age and use, virtually all fixed bed rail press like C&Ps and the variants are well worn and technically worn out.

I love my own personal 10x15 C&P that I have been printing with for 56 years, but for ease of printing with less hassle on most jobs, the work goes on either my Heidelberg platen or Miehle Vertical.

Fritz

Hi Everyone,

Thank you for all your suggestions. This is for our C&P 14.5 x 22.

I have talked to several machinist who can possibly help me on this and they have declined. Most of the people here in my country aren’t used to fixing machines like these.

Fritz,
So you’re suggesting that I use only the tapes that I ordered to fix the height and not have the bed rails itself fixed? I was actually thinking of having a clip-on type of square tube over the bed rails.

Thank you everyone.

Woyinaj

We do not use photopolymer plates though but zinc metal plates.

Woyinaj

I think beginners in particular are over reacting to potential problems they may have with any particular press. In the case of this 14 1/2 x 22 C&P, this press to start with was not that precision a piece of equipment as compared with the more sophisticated presses like Heidelbergs or Kluges. Add in years of use and potential abuse, and I doubt that anything will make the platen exactly parallel in all respects to the bed of the press or make the bed rails exactly type high for inking. This bed of this press exceeds what most of us can safely handle in taking the press apart and most medium to smaller machine shops probably couldn’t handle the work of planing down the bed rails.

The practice of putting a large piece of type in each corner to level is fine to the point that it gets you close to a solution, but rather concentrate on what the press is expected to print. If the anticipated image area is not going to be larger than say 8 1/2” x 11”, then work on that general area on the press and forget the outside 4 corners. If an image area is not going to run the full height of 14 1/2 inches, then why anguish if the bed rails aren’t perfectly type high that entire length? Rarely would a press that size be used for a full form anyway, so reduce the problem to the actual area being used for inking and printing.

And nothing beats inking up a press and seeing what happens—once past the theory of how the press works, it is the actual act of putting paper in and pulling an impression that counts. Every job presents new problems with various solutions and for beginners, my advice has always been the first work off your press is for yourself and family long before you can expect anyone to pay for your efforts.

Fritz

Hi Fritz,

Thanks a lot for the advise. Been working on the machine now but there are still problems with it. I think because of the rollers the machine that came with that are smaller than the trucks. Still waiting for the roller and truck pieces ordered recently. Hopefully those will fix the problem. I will get back to this discussion with the results.

Woyinaj