Making a special key for NRV removal

Discussion in 'Fettling Forum' started by Radler, Nov 21, 2017.

  1. Radler

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    Christer Carlsson presented here:
    https://classiccampstoves.com/threads/nrv-removal-tips.28407/page-2
    a very nice home-made NRV extracting tool. It is simple and elegant. The only problem is the necessity to have a pump-lid to make a larger hole in it. No problem in Sweden, where ruins of classic kerosene stoves can be found everywhere behind the summerhouses.
    In most countries classic brass stoves are sold for very unreasonable prices, even if they are incomplete, damaged and beyond repair. No good source for parts like a pump-lid.

    I had to repair a Primus No.1 with blocked and damaged NRV. The stove is more than 100 years old, no question that the pump-lid must be left unchanged. I found a new solution. Here it is.
    The tool consists of a very short NRV-key with a square ¼" drive for a 5.5 mm socket and a 5.5 mm Allen key.

    DSC02124a.JPG
    This is the tool in parts. The Allen key just passes the unmodified hole of the pump-lid and is strong enough to transfer the torque.



    The raw material:
    DSC02120.JPG
    a bolt 10 mm diameter, a steel pipe 10 mm inner diameter, 5.5 mm socket, Allen key and some washers 15.7/6.6/0.8 mm.



    DSC02118.JPG
    A quadratic bit of plywood, fixed on the bolt, helps to grind exact square flanks.



    DSC02122.JPG
    The slot for the NRV leaves only 2.5 mm steel at the sides. The pipe is necessary for strengthening the sides.



    How to use:
    DSC02126a.JPG
    the key with socket is set onto the NRV.



    Some washers fill the gap between socket and inner end of the pump-lid when the lid is screwed on the pump. Most pumps have almost the same length.
    The number of washers varies from pump to pump.
    DSC02127a.JPG



    Screwing on the lid.
    DSC02128.JPG

    DSC02129.JPG
    Ready to turn the key.


    I was very surprised how easily even the most stubborn NRV got free. After the first ¼ turn of the key, the lid is screwed off at the same time with the NRV.
    DSC02132a.JPG
    The NRV of the 100 year old Primus No.1.

    No chance to get it out with a standard NRV key, but no problem with the home-made special key!

    Regards
    Radler
     
  2. hikerduane

    hikerduane Subscriber

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    At last, someone posted a version of a no slip nrv tool.
    Duane
     
  3. z1ulike

    z1ulike United States SotM Winner Subscriber

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    That's a very nice tool you've fashioned. I'll have to bookmark this for future reference.

    Ben
     
  4. Metropolitantrout

    Metropolitantrout SotM Winner Subscriber

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    Nicely done! Jerry
     
  5. Longilily

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    Nice :thumbup: I like the method of indexing your flats using the ply square :thumbup:

    I've been acquiring materials to make the 'Carlsson Tool' , but I guess you won't be needing one with that little beastie :lol: ;)

    Good job :clap:
     
  6. ROBBO55

    ROBBO55 Subscriber

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    Nice design Radler.
    It overcomes the problem of the varying threads and pump tube diameters used by some manufactures.:clap:
     
  7. Tony Press

    Tony Press Australia Subscriber

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    @Radler

    Great job! :thumbup:

    Cheers

    Tony
     
  8. Christer Carlsson

    Christer Carlsson Moderator SotM Winner

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    Oh, you... :oops: The 'Carlsson tool'...
    OK! It sure has a ring to it.:lol:

    Radler, I think you have done an excellent version of the non-slip tool.
    Good idea, and nicely done to share an easy way for people to make a tool for themselves. :thumbup:
     
  9. Longilily

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    Ha ha, thought that would make you chuckle Christer :lol:
     
  10. Christer Carlsson

    Christer Carlsson Moderator SotM Winner

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  11. IvanN

    IvanN United States Subscriber

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    :thumbup::thumbup: Double thumbs up!
     
  12. snwcmpr

    snwcmpr SotM Winner Subscriber

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    :clap: :clap: :clap: :clap: :clap:
     
  13. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

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    It certainly is, together with the way you constructed it.

    Brilliant work.

    John