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Tuesday, 29 March 2016

Making Your Own Rubber Straps for the Olivetti Valentine Portable Typewriter Case

I often get asked for advice in finding replacements for broken rubber straps on the Olivetti Valentine portable typewriter case. To be honest, I have no idea whether these are available or where they might be obtained. But I do know what it's like to have a strap break. The last time I was asked about replacements was earlier this month, and I suggested to the frustrated father who'd just bought his young daughter a strapless Val, "Surely it must be possible to make your own, using Clark Rubber." That off-hand remark played on my mind a bit - "Is it possible?" I kept wondering. So today I decided to test out the idea myself, to see if I could do it. I succeeded. Admirably.
Let's start with the all-too-common problem. Adam Richardson summed it up on the Mass Made Soul blog: "[The Valentine] came with a slide-on case that ingeniously fastens to the back plate of the typewriter with rubber straps. Unfortunately, over time these ... often dry out, crack and break off. This example still has them intact, but given its age, it's not a good idea to rely on them to carry it around!" I can't stress how much I agree with Adam on that last point.
Fortunately, when you take a close look at the manufacturers' strap, you will see it is made up of three distinct sections - the grip (with the thumb circle), what I call the crossbars (three separate layers of rubber), and the bottom part, or "tail", which slots inside the case and is held in place there by a small metal bar. The fact that the strap comprises three parts glued together means it is relatively easy to make one yourself. 
OK, so here is what one needs for a broken strap solution:
1. Two strips of rubber, 2in wide and about 1/8in thick. One strip should be quite rigid, with very little if any play in it, the other fairly flexible, with a reasonable amount of stretch (the flexible strip will be slightly thinner than 1/8th of an inch). Test the elasticity of the flexible strip - it should extend by a quarter to half an inch when held an inch or so from the end (see second photo below). These strips cost me $5.50 a metre. Take an intact strap off a Valentine case to use for guidance. 
2. Araldite glue or something of similar strength. Bear in mind that while the packaging says it bonds in five minutes, the small print adds that it takes 16 hours for it to set properly. You will need the full 16 hours for a truly secure strap. Don't attempt to test the strength of the hold of the three sections before then. 
3. Strong, sharp scissors to cut the rubber, a Stanley blade for trimming it, a Biro to mark the rubber, a small ruler, 2-3 Bulldog paper clips to hold the sections together while the glue sets, and nail polish remover to clean up excess glue. Also, something from which to fashion a stud to hold the tail inside the case (I used the clipped off end of a paper clip). I also found it useful to use the flame from a cigarette lighter to lightly run around the edges and get them more rounded and smooth.
The dimensions of the strap are: 3in long overall, length of grip section 1 3/4in, length of flexible tail section 2in, width of grip and tail sections 5/8ths of an inch, total end-to-end width of completed crossbars 1 7/16ths inches, total thickness of completed crossbars 3/8th of an inch, edge-to-edge width of  crossbars 3/8th of an inch.
Once the sections have been cut, there is more than one way of assembling the strap. I tried two. First, I cut the flexible tail section and glued it to the 5/8in wide rigid strip that comprises the middle part of the crossbars. Then I glued these two parts to a 2in x 2in piece of rigid rubber from which I fashioned the grip. Before cutting this last section, I tested the strength of the construction and it proved entirely satisfactory.
The other way was this:
For all the success of this project, I have to admit that being able to make one's own strap is more for show than anything else - nothing worse than the forlorn look of a Val case with a broken strap! Or worse, strapless. So I'll still be carrying the Val around with a hand under the case, as I do with any portable typewriter, rather than by the handle. Oh, he of little faith you say? Well, maybe, but since the manufacturers' straps break so frequently, I wouldn't risk it either way.


Joe V said...

Very nice DIY solution, Robert. This reminds me of that common Olivetti Lettera 22 problem of the broken zippers on the case. I've taken to using a military-style web belt to secure my Olivetti soft cases.


Richard P said...

Wow. Just what I need for the Val I picked up in Buenos Aires. Now, is there a way to make missing orange spool nuts?

This looks a bit challenging. I bet you would have takers (including me) if you offered some replacement straps for sale.

Unknown said...

I am in the USA, and my friend has one with the same problem. What he did is buy some cordura straps from the local outdoors/mountaineering/rock-climbing store. He then devised a cordura strap using a couple of snap-on type buckles and a length of cordura material. I will post pictures of his completed project in the next day or two. Thanks for your wonderful blog.

Britewriter said...

Thank you for the tutorial. Even though my three Valentines all have straps, you never know what the future brings. Robert, do you know how to take out the carriage? One of my Olivettis needs a good cleaning qnd I'm afraid to unscrew it without knowing how to put it back together. Previous owner accumulated a lot of dirt and than covered it in oiI.

SalonVip said...

You should make more and sell them. Great tutorial. thanks

P.J. said...

Hi there Great blog! My strap is broken too and I’m going to attempt to build one on my 3D printer. Just waiting on the correct material and time to draw up the strap on CAD. Happy to share the end result. Also, if successful il share the file and requirements so everyone has an option to get a printed replacement. Regards P.J.

P.J. said...

Hi there, I’ve replicated the strap in autocad and 3D printed it in TPU flexible material. I fitted the strap to the original metal fittings and it works great. If anyone would like the file to print themselves I would be happy to provide for free, or if you would like me to print straps for you I would be happy to do so. Also free service, just to cover postage if international. Hope this helps! Thank you P.J.

sebastian ahlqvist. said...
This comment has been removed by the author.
sebastian ahlqvist. said...

Hi there P.J!

I am in dire need of new straps for my Olivetti and would love to have a new pair printed. Will pay for postage and materials ofc. Do you have any photos of the results? I am very curious :D



Sebastian Ahlqvist said...


I would love a pair of new straps for my Olivetti. Will pay postage and materials ofc etc ofc. Do you have any photos somewhere of the results?

Best Regards,

Guillaume R said...

Hi everybody !
@P.J, please. I need a pair of new straps for my Olivetti too. Is it possible to get the file to print them or could i purchase the product ?

Best regards,
Guillaume from Bordeaux (FR)