British Letterpress

Tag: Moving Machines

  • Taking an Arab Apart

    Taking an Arab Apart

    This is an account of dis­man­tling a Crown Folio Arab Plat­en. The machine is ear­ly (Ser­i­al Num­ber 1086 c. 1892) but has had a num­ber of safe­ty fea­tures fit­ted. The guide below shows the major steps and will be added to. There’s a spe­cial sec­tion at the foot of this page about the brak­ing sys­tem.

    The main body of the Machine

    The start­ing point: a com­plete Arab

    Arab: com­plete machine with spare ​“Arab Wheel” shown

    Ink­ing Disk Removed (remem­ber to replace the bolt under­neath).

    Arab: Ink­ing Disc Removed

    Feed board removed

    Arab: feed boards removed

    One of the ink­ing arms removed. Remem­ber that they are under the pres­sure of a spring so you have to keep hold of the arm as you release. In prepa­ra­tion for this you should have removed the rollers and stocks; and also removed the met­al bar which links left and right roller arms: keep this safe!

    Arab: ink­ing arms removed

    Over-arch­ing guard removed by unbolt­ing one site of the guard bars (not pic­tured)

    There are two strong springs which force the front plat­en towards to back plat­en. These need to be un-hooked while the front plat­en is almost ver­ti­cal. The two col­lars and hooks on the plat­en site need to be loos­ened so that the bar can be slid out lat­er on.

    Arab: Plat­en Springs Removed (look­ing from front to back under the machine)

    The two bolts on the left of the front plat­en must be removed so that the front plat­en is held only on the sup­port­ing bar. Remove the sup­port­ing bar and lift the front plat­en out. This is fair­ly del­i­cate as it will still con­tain the frisket motion.

    Arab: front plat­en removed

    The Arab wheel can now be slid from left to right and removed from the machine

    Arab wheel removed

    The ​‘rock horse’ is now removed. This is the U‑shaped met­al cast­ing which forces the front plat­en upwards. This rests in two slots is the frame cov­ered by two semi-cir­cu­lar cast­ings bolt­ed down.

    Arab: rock horse removed

    The back plat­en is now removed as a sin­gle large unit: includ­ing the plat­en and the sup­port­ing cast­ing. This is very heavy but will save trou­ble because the back plat­en will not have to be re-adjust­ed. The eccen­tric is also removed: this is the rod which holds the impres­sion lever.

    Arab: back plat­en removed

    The braking system

    Side view of the brak­ing sys­tem

    Arab: brak­ing sys­tem from side

    Top view of the brak­ing sys­tem

    Arab: top of brak­ing sys­tem
  • Buying and Running an Arab

    Buying and Running an Arab

    The Arab is a mix of cast-iron frame; steel rods and brass. Machines were fet­ed for their reli­a­bil­i­ty and stur­di­ness. They have to be kept well-oiled and clean. When buy­ing, look out for –

    • cracks in the frame (dif­fi­cult to repair)
    • jud­der on open­ing the plat­en (could be a symp­tom of sig­nif­i­cant wear in the bear­ings)
    • any loose­ness of the plat­en: test by try­ing to pull the plat­en apart from the forme when closed up

    The machine body was paint­ed in ​‘Roy­al Blue’ but debate con­tin­ues about the exact shade, and whether dif­fer­ent shades were used. The brass roller arms were the only part of the machine to be paint­ed ​‘Pil­lar Box Red’. While the machine alone is great, also look out for –

    • man­u­als or erec­tion instruc­tions
    • addi­tion­al chas­es — the Arab came with full-size and ​‘but­ter­fly’ chas­es; or even this slant­ed chase
    • roller stocks and bear­ers (per­haps for a third roller)
    • spare parts

    Dismantling an Arab

    This is a rever­sal of the erec­tion instruc­tions and is based on expe­ri­ence. Remem­ber to keep parts togeth­er as far as pos­si­ble (eg replace nuts on bolt ends as soon as they are removed) and keep things in whole, com­plete ele­ments — like the brak­ing mech­a­nism — remove this as one unit.

    1. Ink­ing mech­a­nism
    2. Feed boards
    3. Tym­pan — by remov­ing the blan­ket rod and wire
    4. Forme Ink­ing Equip­ment
      1. Ink­ing roller bar, ink­ing rollers and run­ners
      2. Roller brass­es — care­ful of the springs
      3. Swinger bars which hold the
      4. Ink­ing disk and bear­er
      5. Ink disk pick lever
    5. Safe­ty Guard
    6. Arab Wheel should be loos­ened
    7. Spring and Plunger to hold the Chase on the back plat­en
    8. Con­nect­ing Rods
    9. Back Plat­en
      1. Low­er the back plat­en
      2. Remove the bolts from the foot of the back plat­en legs
    10. Fly­wheel — remove with nut (may have left-hand thread)
    11. Trea­dle and con­nect­ing rod
    12. Frisket mech­a­nism
      1. Strap Guide Rod
      2. Blan­ket and Frisket shafts
      3. Frisket springs
    13. Die Plate and Bush­es — this is the thing which holds the rock-horse against the plat­en
    14. Remove springs from the Plat­en Hooks
    15. Front plat­en — by remov­ing the rod, and col­lect­ing the plat­en hooks
    16. Remove the Arab wheel all togeth­er
    17. Impres­sion adjuster
    18. Eccen­tic shaft (con­nect­ed orig­i­nal­ly to the impres­sion adjuster)
    19. Rock horse
    20. Crank shaft — orig­i­nal­ly con­nect­ed to the fly­wheel
    21. Clutch and trip link
    22. Remove the bolts on the stays
    23. Take one side from the oth­er

    Re-Erecting the Arab

    You can start work on get­ting the machine back togeth­er by fol­low­ing the orig­i­nal instruc­tions that came with each machine.

    Documentation

    The orig­i­nal doc­u­ments that came with each Arab have been con­vert­ed to PDF files by Steve Fish­er and Ben Wein­er. The Arab Parts List should be used with the Erec­tion Instruc­tions