Optimus No.45

Discussion in 'Optimus No:45' started by Cookie, Dec 7, 2019.

  1. Duck United States

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    I want to thank you guys for the links. I was looking for a travel cap not reserve cap and nothing showed up. Duh!
    I looked at Juliands and must have missed this. I’m feeling a little inadequate today. Need to step up my searching game.
     
    Last edited: Dec 9, 2019
  2. Cookie

    Cookie United States Subscriber

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    @kerophile One of the major things that I first notice now when looking at older OP.45's is the sunken filler tube thanks to kerophile. I also noticed the difference in the "NO" part. Looking at kero's 1930's model 45's in the reference gallery there is a double underline below the "0" whereas mine has a single underline. I have also noticed that the number "5" and the letter "T" are different.

    My stove
    DSC_0004a.jpg

    Kerophile's stove
    1410693363-St.370.-Op.45-Sept-14-5a.jpg

    My stove
    DSC_0001a.jpg
    Kerophile's stove
    1410693363-St.370.-Op.45-Sept-14-5b.jpg
     
  3. Staffan Rönn

    Staffan Rönn SotM Winner Subscriber

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    Sorry if I'm a bit off topic, but I found the comments on sunken filler tube interesting. The Swedish Primus patent from 1919 can be found here: https://classiccampstoves.com/threa...atent-48624-1919-and-the-british-gb171536.66/

    This is quite an early patent. I don't know if the time period a patent would be valid and provide protection was longer back then, now it is usually max 20 years. Maybe Optimus was a bit slow on the bat to incorporate this feature?

    The next thing I wonder is if Optimus incorporated the sunken filler also on other models around this time (late 50's). It would then help the dating of other models. The 111's from mid 1950's that I have do not have sunken filler tubes. I don't have any late 1950's / early 1960's to compare with. My next version is from 1990 and it has a sunken tube.
     
  4. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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  5. Staffan Rönn

    Staffan Rönn SotM Winner Subscriber

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    Thanks @kerophile , very interesting and great list in the link.:thumbup:

    I realize now that due to shortcomings in my English vocabulary I mixed the recess solution up with the prolonged filler tubes that is an alternative design to prevent overfilling (like on the 111's I was referring to).

    BR/ Staffan
     
  6. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi @Staffan Rönn No worries. I had worked out what you meant. Two approaches to the same challenge: How do you prevent over-filling of a fuel tank.
    Best Regards,
    Kerophile.
     
  7. Staffan Rönn

    Staffan Rönn SotM Winner Subscriber

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    Thanks @kerophile ,
    Have you seen any pattern or timing in the introduction of prolonged filling tubes that could help dating on stoves with this approach?
    BR/Staffan
     
  8. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi @Cookie Useful observations of the form of lettering and double underlining of No. on earlier optimus 45 models.

    Just so that there is no misunderstanding, the sunken filler feature is a feature of later No.45 and some other classic Optimus stoves. The earlier Optimus stoves has flush-mounted filler tubes, and it was only in 1957/8 that they introduced this “new” feature to their Op.45 and Op.48 models.

    Best Regards,
    Kerophile.
     
  9. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi @Staffan Rönn , the elongated filler tube on No.8 and No.111 stoves is a hidden secret. You cannot see it in catalogue illustrations, nor in spare part listings, so you really need to have the stove tank in your hand to reach a decision. I have half a dozen or so Op.111 stoves but not done the examination yet.....

    Mind you I did a study on the use of soft solder or higher melting-point braze in the construction of No.111 tanks.

    Optimus 111 Pump Tube: soldered or brazed

    Best Regards,
    Kerophile.
     
  10. Cookie

    Cookie United States Subscriber

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    @kerophile Yes kero. I am following you on the sunken filler feature. I just wanted to point out my observation in an effort to learn more and to possibly assist others in dating the 45' & 48's. Thanks