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Wednesday 15 February 2012

Help! Caligraph Typewriter Repair

Richard Polt is a very wise young man. When I announced I'd bought a Caligraph, Richard commented: "Notice the silly mainspring - that long spring wound around the shaft that runs from front to back on the bottom of this machine. Silly because this arrangement requires very high tension on the spring to keep the carriage moving. Often these springs break on Caligraphs. Just a word to the wise."
Sure enough, my Caligraph arrived from Melbourne this morning and the mainspring was broken, about 3 inches from the front end. I hasten to add the seller had been honest enough to point this out, so it came as no shock.

I have managed to remove the broken-off piece of coil.
I am wondering now whether it would be possible to attach the remaining coil to the screw at the top of the rod. It does stretch that far, but would I be putting too much tension into it? Obviously I'd have to make a small hook at the end of the remaining coil, similar to the one at the other end. Welding doesn't seem a viable proposition: I doubt if a welded join on so thin a coil would be strong enough hold the tension.
But I also suspect the spring will have to be rewound. Is anyone able to advise on this? Thanking you in advance, if you are.


Richard P said...


My guess is that the old spring is now worthless, and if you want a working Caligraph you will need to find a new spring of the right length, shape, and strength. But I have not done such a repair before, I am just guessing.

PS: Thanks for calling me young.

Robert Messenger said...

Thanks Richard. I suspect you may be right: my Cali may be destined to be a display piece only - but it is very impressive to look at. It's much wider yet very much lighter than I had expected. I had seen one in Melbourne, but recalled it as a slightly difference, higher, thinner shape. As you say, all the design faults are fairly glaring. I suppose it's only real advantage at the time was the double keyboard (and the spacebars?). It was cheaper, too, wasn't it, which would account for its initial sales.

Robert Messenger said...

Oh, and by the way, you are young to me, and far sharper in thought too!

Robert Messenger said...

PPS: I also put a call out to Bill Wahl on the Facebook typewriter collectors page, hoping he may have some thoughts on the subject.

Scott K said...

Okay... I have some ideas for you. But first, can you detail the function? Are you able to remove the entire remaining spring section out of the typewriter?

If so, when you have, see if you can flex the spring by twisting it in your hands. If you need to, wrap it around a piece of dowel and twist it.

Are you able to easily twist it by hand? Or is it hard and resists your turning.

Considering the way it broke, I'm guessing the former, rather than the latter.

These springs were easily produced. They are made of a piece of metal, or more or less a piece of wire, which was fed into a machine that forced it though a curl. The technique hasn't changed much ever since.

The reason I suggest you do this twist with the longer part, is you'll be able to get a better sense of the kind of tension - or resistence that the spring has.

A friend with a lathe can make you a new one. You just need to gauge the inner diameter of the spring, and find a piece of dowel to wrap it around. If they're any good with a lathe, they can feed it onto a dowel manually.

A lot of machine shops have a tool that bolts onto a lathe, to feed wire onto a dolly for this specific purpose. I can detail how to do such a process, but most engineers will know how... Or fitter and turners.

It's just a case of getting the wire. You can probably find a steelshop, or even a bunnings that sells lengths of wire in various gauges. The quality of the steel used today will be far better than the existing part. If it flexes really easy, you can probably find a nice soft(ish) steel, and quite possibly even twist it onto a piece of dowel by hand.

But I have to say... that part is dead. From here, it looks like a spring designed to apply pressure, (Spring is pressed) rather than to retain tension (spring is stretched). So you will need it to be full length.

Scott K said...

Or... Alternatively...

Get the dimensions you need off your typewriter, and contact someone like -

Scott K said...

Gah! That was meant to read Latter. rather than former up there.