This Blickensderfer 5 typewriter was out of adjustement from severe knocks to the frame - so it was unavoidable to attempt to re-adjust the typing mechanism. Adjusting the typewheel mechanism with its several set-screws dotted around the machine is somewhat intimidating, further made interesting by the bent-parts taking some adjustments out of the range of the set-screw.
Even though intimidating, there logically has to be a way to simply converge on a properly adjusted Blickensderfer step-by-step. The factory turned out hundreds of machines per week - there will have been a 'recipe' for the adjuster to efficiently adjust a machine. (Some of the training material or instructions for the factory would have been great here.)
The basic method of selecting the right rotation for a specific key is fairly straightforward. As nicely illustrated in below sketch, the wheel is rotated by the difference in deflection between bars G and D as actuated by the stepped-section of the key-lever.
The bar D is actuated first, rotating the wheel as it rotates one "quadrant" C downward via the transmission of the geared-prongs (essentially very small sections of large gear-wheels). The rotation stops when the keylever also touches and starts actuating the bar G that causes the whole typewheel stack plus the other quadrant B to start moving in sync with C. Also moving quadrant B is part of the trickiness - this is timed via the set-screws on the base of the mechanism. Quadrant B is actuated via a prong (with set-screws) that is part of bar G.
Another trick is that the static quadrant is locked at first, to prevent any slippage or being pulled along as the wheel rotates. It is held by the hook shown in the diagram; only by actuating the bar D corresponding with the quadrant is this hook pulled out of the way to allow movement.
The start of ajusting probably was to set the set-screw for each side to to start touching the other side's prong just as the universal bar G starts to move. That means for the right side of the keyboard, the left set-screw must be set to ensure the left prong moves in-sync with the central 'universal prong' and vice versa. Likely that is the start of adjusting the base. The next step is to check that the least-deflection keys (here T and E) are balanced. And when the top-assembly is installed, to screw inward just enough for the lock to be released. I.e. for the unlock of key E on the right-side of the keyboard the left screw (red) and vice-versa.
On this banged-up specimen the left-side could not be brought in-range. At the maximum setting, the letter E would not rotate before the universal bar G stopped it. To fix without attempting any more bending, bar D was padded with copper shim to 'cheat'. This is too soft and not durable, but it'll hold for now.
The three set-screws on the top-assembly regulate the wheel locking-moment and release - when the balance of T and E is right and the opposing quadrant is unlocked just-in-time, then the centre screw (yellow) sets the range of the end-rotation. This then adjusts so that the largest-deflection key (Z and J) register correct.
Another trickiness of the mechanism is a prong that locks the typewheel in its rotated state from below. Probably its function is to prevent any smudging from the wheel starting to rotate back before it has fully left the paper. When the typewheel stack is rotating back upwards again, this lock needs to be pushed out of engagement. The right set-screw (purple) adjusts the timing via a bail to trigger this unlock. It is sensitive. (The left set-screw is an imposter; this merely is the mounting srcew of a spring.)
After a lot of time staring at the mechanism and imagining what the steps would've been, this little Blickensderfer 5 is starting to make sense again!
There still are some characters that are at the edge of their range (wrong character about 1 in 10 times) and the unlocking is likewise at the edge. I.e. when depressing the lowest-rotation character, a clear resistance is felt from the other side's quadrant slipping off the locking-hook. Even though this adjusting mostly worked, there are likely more details/tricks (that were well-known in Stamford 120 years ago). Probably more small tweaks as the machine 'settles in'.
Another aspect is that the adjustments and details of the wheel mechanism were changed over time by Blickensderfer - this adjustment worked on a 1905-ish No. 5, but an older or newer machine or e.g. a No. 8 are likely to be slightly different.
Result is that this project machine has now cleared its biggest hurdle to again becoming a typing machine! :-)
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