Ensamblar y desensamblar los prensas grabado Polymetaal serie JW

Disassembly of etching press JW series
In this description we refer to the next image "cross section etching press JW-series". This "drawing" is not on scale and is adapted in such a way that it gives a clearer understanding of the construction of these presses;

1. The press is probably fixed on a pallet and packed with plastic. Take the plastic of and release the press from the pallet. Leave the plastic to protect the cylinders.
2. If the bed is situated between the two cylinders, take it out.
3. Make, in one way or another, a fixed point above the press that allows you to hoist the cilinders. Bring a tackle in that fixed point. Important; see Nr. 14
4. Release the spindles (1) on top the upper cylinder, and take the spindles out of the side frames.
5. Take the hand wheel (16) from the gear box (18). There is a small screw in the hub oh the wheel that has to be released first.
6. Take the gear box (18) from the lower cylinder (7). For this you need the special hexagonal key (9) that is fixed to the hand wheel with tape. This key is very short on one end and this allows you to release the two screws M10 (8)(cyl.head screws with inside hex.) from the gear box.
7. Take the key (19) and the circlips(20)(also from the opposite end) from the lower cylinder.
8. Take the pressure blocks (14) and (if present) the cardboard pile (15) from the press.
9. Fix a good rope at the middle of the upper cylinder and hoist it with the tackle to such a level that it permits you to take the two springs (N) out. Now you can lower again the upper cylinder and take the rope off.
10. Use a good and strong rope to connect the two cylinders to eachother and to the tackle, like this drawing shows; For reasons of simplicity the side frames are not drawn.
11. Try to hoist these to cylinders together, untill the press as a whole is almost lifting from the ground.
12. Release the screws of the round bars between the frames. There are eight screws to be released (13) M12x45 (ins.hex cyl.head) and eight screws M8x20 (ins.hex cyl.head) which are hidden behind slotted holes on the inside of the side frames. These screws keep the round bars in place that carry the white plastic rollers.
13. Release the cyl.head screws M10x40 (11) and the hex.bolts M10 (24) that keep the cross in place.
14. Now everything is ready to take the side frames away. Be very careful. The two cylinders are connected to the tackle. The weight varies depending upon which press it is in the JW series. The weight may be something like 300kgs. Be sure that the rope, tackle and fixing point can have this weight without any problems.

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    (POLYMETAAL does NOT use rope to connect the two cylinders. We have a special divice (a combination of wooden blocks; something similar to a divice used in Europe in the Middle Ages to secure someones wrists and head in a woodblock. This way the person was exposed to the public's anger as a sort of punishment) You are free of course to use these woodblocks if you are not too far from Leiden in Holland. But in this description I have tried to use as few special tools as possible.)

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    Also verify that the ropes are connected symmetrically on the cylinders. If not connected symmectrically the cylinders may tilt is opposite directions. Failure to properly lift the cylinders may cause serious injury or damage to the cylinders. Now is the time to double (or even tripple) check, bearing point, tackle and rope.
15. Slide slowly one side frame from the shaft of the lower cylinder. Putting some grease on the shaft will make the sliding easier. The two cylinders must stay where they are during this proces!! Slide the second side trame from the cylinders and lower the two cylinders and lay them carefully on the ground.(take the rope away)
16. Now the diassembly is completed.

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    Assembly of etching presses JW series.

    May be you just have disassembled the press because you had to move to another place or you received the complete assembled press and it did not fit through the door. It is also possible that you received the press in a dissassembled state. These different options cause minor differences in the assembly procedure. First you find here a list of all the components of an etching press from the JW series;

    • 1 gear box. Hollow shaft 35mm, solid shaft 24mm, gearing 1:12.
    • 1 bed of very hard synthetic material. Size; JW-80 80x160cm, JW-100 100x200cm and JW-120 120x220cm. These beds are fitted with two bars of hard wood the prevent the bed from falling out the press.
    • 2 springs, diam. 5cm length 21cm. These springs keep the top cylinder up. This is very convenient for relief printing.
    • 1 side frame, fitted with holes for the gear box.
    • 1 side frame without holes for the gear box.
    • 4 guide "strips" to be fixed to the side frames to keep the bed in place.
    • 2 pressure blocks, to be placed directly under the spindles. They are designed to distribute the pressure over the cardboard pile.
    • 2 guides for springs. Diameter 35mm, with a hole of 13mm.
    • 2 bearing blocks for the upper cylinder.
    • 1 upper cylinder.
    • 1 cross to fix between the two side frames.
    • 1 lower cylinder
    • 8 plastic white rollers to guide the bed of the press vertically.
    • 4 bars to carry the white rollers. (Bar size, JW-80 round 20mm length 845mm M8, JW-100 round 20mm length 1045mm M8, JW-120 round 25mm length 1245mm M8.)
    • 4 bars to meet the distance between the side frames. (Bar size, JW-80 round 30mm length 845mm M12, JW-100 round 30mm length 1045mm M12, JW-120 round 35mm length 1245mm M12)
    • 1 hand wheel. (hole 24mm)
    • 2 pressure spindles M30.
    • 4 hex. nuts M30. Put these on the spindles, to be able to fix and hold a certain position of the spindle.
    • 8 cyl.head screws ins.hex.M8x20 for the round bars with plastic rollers.
    • 6 cyl.head screws ins.hex.M10x40. Four for fixing the top ends of the cross to the frames and two for fixing the gear box.
    • 8 cyl.head screws ins.hex.M12x45 for the main round bars between the frames.
    • 1 adjustment screw M8x16 ins.hex. for fixing the hand wheel.
    • 8 hex.bolts M8x16 for fixing the guide strips on the side frames.
    • 8 washers M8 for fixing the guide strips on the side frames.
    • 4 hex.bolts M10x25 for fixing the lower ends of the cross to the side frames.
    • 16 circlips for diam.20 (JW-80 and JW-100) or diam.25 (JW-120) for securing the plastic rollers on the round bars between the frames.
    • 2 circlips for securing the lower cylinder on both ends.
    • 1 key 8x7x32 for connecting the hand wheel to the gear box.
    • 1 key 10x8x36 for connecting the gear box to the lower cylinder.
    • 4 plastic black plugs to close the tube ends of the side frames
    • 1 turn handle for the hand wheel.

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    1. Connect the two cylinders with a good rope, according to the drawing "detail of hoisting cylinders", on this page. To determine what is what; the lower cylinder has a fixed shaft. The shaft of the upper cylinder can turn.
    2. If the press was assembled before, the bearing blocks(J)and spring guides(M) are still mounted on the shaft of the upper cylinder. If the press was not assembled before; Glide the bearing blocks over the shaft as the picture shows. Keep in mind that the hole round 40mm is excentric !! in the block. The hole should be in the lower half of the block. Fix the spring guide by means of the hex.bolt M12x110. This bolt can be tightened now. Place the adjustment screw (I) M12x20 but do not tighten it. It must be possible to glide the bearing block over the shaft.
    3. Hoist the two cylinders to the right level. When the cylinders are hanging more or less in the right position, check this by placing a side frame next to them, the hole in the side frames with the ball bearings in them must be at the same hight as the shaft of the lower cylinder. Now put some grease on the shafts of the lower cylinder.
    4. Place the two cyl.head srews M10x40 (for fixation of gearing) in the side frame. If you forget this now, you have a problem later.
    5. Try to glide this side frame over the long shaft of the lower cylinder. Do not force this. If the frame is in the right position is will enter easily. At the same time, check if the bearing block (with spring guide pointing downwards) enters also correctly into the side frame. Leave a few free; do not slide the frame until the end. You will need some space afterwards to put the parts between the frames in place.
    6. Glide now the other side frame im the same way over the shaft.
    7. Place now first the four bigger round bars (3) between the frames with screws M12x45 (13). Do not tighten these until you put all parts between the frames.
    8. Release the cylinders from the rope, and take the rope off the cylinders.
    9. Place the smaller round bars, with the plastic rollers, now between the frames. (with cyl.head screws M8x20) the screws are fitted in slotted holes. This is done to give a possibility of adjusting the hight of the plastic rollers. If the plastic rollers are not yet fitted on the round bars, do it now. Secure each plastic roller with a circlip at each side. Each roller should be about 20 cm from each end of the bar.
    10. Place the cross between the frames. Fix them at the upper side with cyl.head srews M10x40, and at the lower side with hex.bolts M10x25. The cross is assembled by welding in a jig. In spite of this, there may still remain some tension in the cross. Keep this in mind while placing the cross. Do not tighten any screws yet.
    11. Start now tightening the srews M12x45 very firmly. Do not force anything, and switch from one side to another while tightening the srews.
    12. Now tighten the srews and bolts of the cross.
    13. Bring the two circlips (20) in place to secure the lower roller.
    14. Bring the key (19) 10x8mm in place, and the gearing system. Use the special key for tightening the cyl.head screws M10x40. This special key you can find fixed with tape to the hand wheel. With this special key, you can enter between the side of the lower cylinder and the side frame. Tighten the screws in the gearing firmly.
    15. Bring some rope again on the middle of the upper cylinder. Hoist the upper cylinder with the tackle about 20 cm. Now you can determine the place where the bearing blocks must be fixed on the shaft of the upper cylinder. But beware, the bearing blocks need a few mm play sideways!! Now tighten the adjustment screws M12x20 (I)(25).
    16. Now you can also bring the two springs in place. If necessary hoist the top cylinder a bit more to facilitate the entering of the springs.
    17. Let the upper cylinder go down slowly, until it rests on the springs.
    18. Cut some cardboard if you want some "flexibility" on the upper roller. Make shims of it and put in into place. Put the pressure block on top of it. (In the old days presses were made of cast iron, that could break easily under high tension. For security reasons a pile of leather or cardboard was placed under the spindles. In case of an "accident" (a screwdriver lays forgotten on the bed) the extra and sudden tension could "escape" through the pile of leather and would hopefully not damage the frames. Nowadays most frames are made of steel, and can support much more tension without breaking. But partly for tradition and partly for "flexibility" the shims of leather or cardboard are left in place. It has certainly a function when the upper roller has to "follow" a surface that is not perfectly plane, like with woodcuts and lino cuts).
    19. Put some grease on the spindles, bring the hex. nuts M30 in place, and turn the spindles into the side frames.
    20. Now remove the protective layer of plastic from the cylinders. Use a very sharp knife for this, AND CUT ONLY IN THE PLASTIC SURFACE, otherwise you might damage the cylinders. Clean them with solvent and make them dry.
    21. Now bring now the bed into place, and adjust it. Attach the bed guides to both sides of the frame with hex.bolts M8x16 and washers. These guides must be fixed in such a way that they guide the bed in a straight line through the press. Do not block the bed with them. The bed needs 1mm play on each side.
    22. Now adjust the bars with the plastic rollers. Adjust them to such a hight that will allow the bed to pivot atop the lower cylinder. This pivoting action, caused by the difference in hight between the lower roller and the plastic rollers, can be minimum and is solely to ensure continues contact between the bed and the cylinder.
    23. Bring the plastic plugs into place in the ends of the tubes of the side frames.
    24. Mount the wheel on the gearing system and fasten the handle onto the wheel.

    The press is ready for use. If there are still questions, do not hesitate to send a question or a message; e-mail info@polymetaal.nl
    

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