Making Tab Stops for an LC Smith Typewriter




About: I enjoy taking a pile of junk and making something unusual out of it. I like wheeled vehicles, and currently own two motorcycles, two electric bikes that I've built, and an electric scooter pushed by a soc...

I realize not everybody needs to put tab stops into an 82 year old typewriter, but if that happens to be a goal in your life, this Instructable is for you!

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.

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Step 1: How Tab Stops Work

I knew I would need to make two tab stops (one for the decimal position, and one for all the others).  I decided I would go ahead and make 5 instead of 2, since I could use the stops to set multiple tabs if I wished.  I couldn't find a photo of what the tab stops looked like, but it wasn't too difficult to figure out where they should be installed and what they needed to look like to be functional.

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

I measured the width needed for the tab stops to straddle the grooves, and the length and depth needed, and marked the dimensions on the steel bar (photo 1).

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

I now had five tab stops to tune.  Tuning involved adjusting the width of each stop so that it would mesh correctly when the key was pressed.  I roughed out the width with a stationary belt grinder, then find-tuned the width with a file.

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!

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    5 Discussions


    2 years ago

    Thank you so much for this detailed explanation. I have been trying for quite awhile to figure out how tabs worked on old typewriters. Various websites have photos, but you can never see if there is a tab key let alone how the mechanism would work!

    Phil B

    8 years ago on Introduction

    Obviously, there will not be a large number of people who need to do this. But, it will be very useful to those who need it, and they will eventually find it through referrals and links, etc. For the rest of us, it is fun to read about how someone else solved a problem, and we look for little hints that we might be able to use on an unrelated, but similar project we might have. You did a good job on sawing the pieces of steel. I would have needed to get close with the saw and then file the rest for a good fit. Well done!

    2 replies
    knife141Phil B

    Reply 8 years ago on Introduction

    Thanks, Phil. I didn't expect that a lot of folks would need to make tab stops for an old typewriter, but at least it's now out there for people to find if they need the info. I've worked with steel for a long time -- for over 20 years I made handmade knives as a hobby/passion/sideline. Steel and I get along pretty well. I decided to take a break from knifemaking 5 years ago, and have followed other passions ever since. In fact, my "Knife141" name came from an old knifemaker's forum many years ago, and I guess it just sort of stuck!

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    Phil Bknife141

    Reply 8 years ago on Introduction

    Thank you for the explanation of your on-line identity. That is a very nice knife. I have not yet been bitten by that bug and I already have more factory knives than I can use. Anytime you want to do any Instructables related to your knifemaking days, I will be glad to read them.