Monday, February 19, 2024

Successfully adjusted carrier return, tab, current line pointer and print escapement

CARRIER RETURN ADJUSTMENT

Although the carrier return was working properly as far as moving the carrier back to the left margin, the escapement and backspace pawls were slightly dragging across the rack teeth. Not only does this make an annoying noise, it can wear away the pawls and teeth. 

As part of the carrier return operation, when the mechanism is latched into the operating state which will remain until the left margin releases the latch, it should twist the escapement torque bar to move the pawls far enough away to clear the rack teeth. The solution was to adjust an eccentric bolt that was part of the latch mechanism. I soon had the typewriter quietly moving to the left during the carrier return, which was the objective for this adjustment. 

TAB ADJUSTMENT

Tab was mostly working properly, but when I would hit tab with no tab stops set before the right margin, the carrier stopped but did not unlatch the tab operation. That would foul up carrier return activation so I had to fix this issue. 

I discovered that the repair I made to the right margin lever, the one that been broken, interfered with the homemade current column pointer I fashioned to replace a missing part. With the interference removed, the carrier properly unlatched when it reached the right most column. 

REPLACEMENT CURRENT COLUMN POINTER ADJUSTMENT

I had to widen the holes in the aluminum part I had created so that it could mount a bit higher on the carrier. This let it clear the right margin lever, which had a metal bracket epoxied to its top as part of its repair. 

With the point moved up and the bends altered slightly, the pointer now clears the margin levers and properly points at the current column so that it will be visible in the plexiglass window when the front panel of the typewriter is installed. 

PRINT ESCAPEMENT ADJUSTMENTS

Moving the carrier a space to the right involves twisting the escapement torque bar out of the way but letting it rapidly return upright. The escapement pawl moves out of the rack, the mainspring pulls the carrier to the right, and the released escapement pawl drops into the next tooth of the rack ensuring a single column movement. 

A pullrod was adjusted as well as an eccentric bolt that sets up the activation lever to snap off the tab of the escapement torque bar, giving that short activation that guarantees the single column move. That eccentric bolt has a screw head which was hidden inside the frame and barely accessible only when partially activating the lever by hand. The other side has a nut and is easily accessible from the rear of the typewriter. I managed to get this set properly after a bit of fussing. 

I had this working well, so that I could move on to the other mechanism for spacing that uses an operational clutch to pull down on a lever when triggered by the Space pushbutton or the space solenoid. This was not tripping the escapement torque bar and I hadn't achieved good operation by the time I was done for the day. 

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