Linotype resatoration

[diddi]

Hi guys, I have recently become involved witha technology museum and as an old Linotype operator they asked my help to get a Model 36 running again. I have been out of the trade for 35 years and when I was in it I didn't have too much to do with the mechanicals so I am a bit lost. I can't get the keyboard cam roll to turn though there is an old leather belt it just slips and there appears to be no idler for adjustment and also the pot heats very slowly but not enough to melt the lead. Anyone have any clues. Any assistance at all greatly appreciated. Cheers, Dave

[Mechanic]

Well Diddi, There are a couple of things you can check on the keyboard. I'm sure as an old Linotype operator some of the things I tell you may seem obvious but I will tell you just to make sure that I cover everything I can think of.

The keyboard rollers require very little effort to drive them, they do not require a tight belt.

The most common thing that stops the keyboard rollers from turning is that a large number of the keyboard cams are sitting on the rollers because someone or something has depressed the keyboard buttons when the machine is turned off and the keyboard is left unlocked. Take the covers off the cam frame and you will be able see if the cams have dropped onto the rollers. There is a stop comb that the cams rest against when they are in the normal position. When a key is struck a little paul is lifted and cam drops onto the roller and the cam is rotated to lift a rod which cause a matrix to be released. The cam continues its rotation until it  rests back on the paul and the stop comb tooth.

If this is the problem  look across the top of the keyboard at the short rods that are part of the keyboard. These are the rods that are lifted by the keyboard cam which acts on another rod to release the matrix. If any of these are raised, turn the pulley wheel in the opposite direction to the normal rotation of the of the pulley that is anticlockwise. If the pulley slips try turning the sprocket wheels by hand. If this fails open the frame that contain the over motion springs and plungers  both at the front and back of the keyboard and the rods should drop down if they don't,  push them down. this will cause the end of the keyboard cam which normally sits under the over motion plunger to pop up. Once all the rods are down you can swing the keyboard out by undoing the large knurled or hexagon hand bolt under the left rear side of the keyboard, just above the clutch handle. Undo it all the way it wont fall out. Unlatch the keyboard elevator handle from the assembler elevator and lock it down under a spring load paul at left hand end of the keyboard. swing out the keyboard out. It rotates around a spring loaded bolt on the right hand side of the keyboard. With the keyboard open you can now gain easy access to the keyboard cams. Make sure the cams are pushed back over the hinge wire directly below where the spring loaded over motion plungers are located. Close the over motion frame. You should now be able to rotate the the cams back to their home position by rotating the pulley in a clockwise direction.

If that is not the problem, it could be that someone has had the keyboard cam frames off the machine and not put them back correctly. First check that the grub screws that screw against the right hand roller bearings are not to tight. They should be firm enough to hold the bearings in place in the castings. If these screws are to tight this cause the bearings to be misaligned and the rollers are hard to turn.

The castings in which the cam rollers rotate are held onto the keyboard frame by large screws or hexagon bolts which also have a screwdriver slot in the head. There are four bolts one in each of the bearing castings. In addition to the bolts there are four small cheese head screws in the side of the castings. Now the only job of the cheese head screws is told the casting on the keyboard frame when the frames are off the machine. Swing the key board out as described above. Slacken the bolts just enough to relax the castings about 1/16 to 1/8 of a turn. Now turn the four cheese head screws until they are just finger tight. Retighten the four bolts. Now try rotating the keyboard rollers they should turn freely.

The only other thing that I can think of is make sure there is nothing in the bearings that could cause the bearings to cease. Remove the guard that covers the sprockets on the keyboard rollers, undo the grub screws that holds the right hand bearing in place the keyboard rollers can be removed . This has to be done carefully to avoid dislodging the keyboard cams.

The following web site is a download for Linotype maintenance manuals etc.


http://www.linotype.org/onlinedocs.html

I am assuming that the metal pot has a Micro-therme control and that the heating elements are tubular. In the crucible there are two elements, they are wired in parallel. That means that if one element burns out the other element will still heat, but not enough to bring the pot to the correct operating temperature of 535 deg f.

I must warn you that the crucible is packed into the pot jacket with powdered asbestos, which we now know can be dangerous if inhaled and can cause lung cancer. However with the crucible elements you do not need to disturb the asbestos which should be sealed with a layer of solid asbestos.

You will need an electrician unless of course you are qualified to work with electricity. Then once you have found the faulty element you will need to get a replacement.

Let me know if you want to proceed and I will do my best to tell you how to remove the faulty element.

[diddi]

Hey George, thanks a bunch for that info. I appreciate the time you have spent to do that. I'm not back at the museum for another couple of weeks to try and put it into practice but you have certainly given me plenty of options to work with. I will keep you informed of progress though it may be slow as I only have a few hours every fortnight or so. Great to find this site and discover there are a few sad old bastards like me who still have an interest in what I believed when I started my apprenticeship at the Auckland Star newspaper in New Zealand in the mid sixties was high technology with a big future. Cheers, Dave Lowe.