Monday, April 4, 2011

Keyboard Cam Roller Friction Spring.

Here’s a simple fix that made a big difference. The slightest amount of resistance caused the keyboard rollers to stop. Even the normal action of depressing a key could cause drag, and it was necessary to give the rubber roll shaft gear a bit of a push to keep things rolling.

After tapping out the collar pin, I gave the friction spring and shaft pulley a splash of white gas and a good scrubbing. Then I carefully bent the spring to give it a bit more tension against the pulley. Much better.

Short Keyboard Rods

Pictured here is the keyboard swung open with the keyboard cam yoke frames removed and various keyboard shields removed. It is important to make sure that no key rods are engaged before the keyboard is swiveled into this position.  If a short keyboard rod is raised when the keyboard is rotated, it *will* bend and it will cause problems. This keyboard had been opened in this manner, and was in need of repair. When swinging out the keyboard, It seems like it is really easy to overlook this detail, especially when all of the shields are in place. I suppose it’s one those things that you learns as Linotype operator: you make the mistake once and you probably won’t do it again. It was a simple fix, but like anything else on this machine it took a little patience and some time.
Here’s a view of the backside of the keyboard. On this machine, the keybars can be removed as a unit. However, the lower key rods cannot.
Sign of trouble. After running my finger along the bottom of the short keyboard rods, most fell back into place as they should. These stuck.
Removing the short keyboard rods was a bit fussy. As soon as I loosened the guide bar, the rods wanted to fall through. Could have been a big mess. It was my goal to keep them in the proper order. If anyone has a trick for this, please let me know. I ended up hand scoring a piece of 18pt board to the dimensions of the bars, and cupped it around the bottom while removing the rod guide. This kept the rods in position so I could clean and straighten them in order.    
Here you can spot the bent rods. If you look closely, you may also be able to see that the brass guides that space the bars have also been damaged. Some are pinching the rods so they cannot move freely. Here I took a small flat-blade screw driver and very gently tapped them back into place. Apparently, I was lucky. Bill Spurling told me that he has seen machines with paper clips or little pieces of wire that replace the brass teeth that have been broken off. This one was in relatively good shape.
Here is a profile view of a bent rod. I used a mallet to straighten it.
More cleaning. Wow. These were really gummed up. But with straightened guides and straightened rods and a bath of white gas, they were as good as new.