This LC Smith & Corona model 8 typewriter was built in 1930. I picked it up at a flea market and spent several weeks repairing and rebuilding it. One of the things that intrigued me about this old typewriter was that it came with "decimal tabulation" keys (see photo 3). These keys were designed to let the typist set tabs for a column of numbers, so they didn't have to use the space bar to align each number typed into the column. It was sort of a novel feature, but apparently never became very popular, because they discontinued this feature after only a few years.
During the process of restoring this old typewriter, I found that the tab stops that worked with these keys were missing.
Well, no problem, or so I thought.
I checked ebay -- nothing. I checked google -- nothing. I checked a couple of vintage typewriter forums, and found that everyone who has attempted to rebuild one of these pretty much ran into the same problem. The tab stops seemed to always be missing, and no one had a source for them.
So, I decided to make my own.
Step 1: How Tab Stops Work
The square bar in photo 2 was made with teeth on it, and the tab stops were made to slip over the teeth. In photo 3 I have pressed one of the tabulation keys, and if you look closely you will see a small metal tooth has projected outward, and this tooth is designed to meet a tab stop and force the carriage to stop.
I found the groves between the teeth on the square bar to be 3/64ths of an inch wide. Luckily, I just happened to have some precision ground tool steel that was 3/64ths of an inch thick!
Step 2: Cutting Out the Parts
Using a metal cutting bandsaw, I cut the piece out, making sure to leave just a little bit of excess where the stop would fit onto the square bar (it's a lot easier to remove steel than to put it back!). I then hand-fitted the stop using a file to carefully widen the opening until it fit just right.
I then repeated this process four more times!
Step 3: Installing and Tuning
That was all there was to it. The project only took about an hour, which was less time than I had spent looking online for replacements to buy!