RM Wickless Picnic Stove

Discussion in 'RM MFG & Engineering Co Ltd' started by Graycole, Aug 21, 2023.

  1. Graycole United Kingdom

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    I was very pleased with the performance of this little stove. I lit it in windy conditions and it flared quite a lot though that may have been partly because the tank had only a little fuel inside. The only original part missing is the flame spreader plate and you may notice two different home-made ones in the photos. One was made of brass and the other is steel (which I made years ago for another stove)

    stove and box.jpg pump close-up.jpg tank close-up.jpg stove burning well with windshield.jpg stove with steel flame spreader.jpg stove with brass flame spreader.jpg stove burning with yellow flames.jpg
     
  2. mr optimus

    mr optimus United Kingdom Subscriber

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    Hi @Graycole welcome to CCS nice little stove, i like the pressure release screw which is mounted on the tank rather combined with the filler cap, the flare may because it is running fuel rich not enough air, this could be due to the flame spreader sitting too low, or an enlarged jet orifice or it has not properly pre heated enough, another point has the burner tube got any brass gauze in it which helps maintain fuel vaporisation by increasing its surface area which the fuel passes
     
  3. Graycole United Kingdom

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    The flaring was worst when the stove was not yet fully heated. Certainly the flame spreader was different from the original kind as seen here; RM Wickless picnic stove
    I haven't looked inside the burner tube yet.
     
  4. mr optimus

    mr optimus United Kingdom Subscriber

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    Hi @Graycole the flame spreader on the home made version does sit lower than the original, this would give a lower air too fuel ratio which could be the reason for fuel rich flame, have you checked the jet orifice, the jet orifice should be 0.23, if the correct size jet pricker has a loose fit in the orifice that would indicate a worn jet which would all so cause a fuel rich yellow flame.
    Another cause of flaring or an over rich flame is the burner bell has a loose fit over the burner tube, this could cause a low air ratio to fuel as the burner tube protrudes past the bottom of the burner bell giving a low air to fuel ratio, and all so less surface contact to maintain fuel vaporisation, in this case the stove would light but would not be able to main proper fuel vaporisation and after a short period the flame would flare up, the same result if there is no brass gauze in the burner tube
     
  5. Magne Fahre

    Magne Fahre Norway Subscriber

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    What a nice little stove :content:
     
  6. Dean

    Dean United Kingdom Subscriber

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    @Graycole
    I just happen to have one of these stoves which I do not think has ever been lit! The flame plate for it is cast iron and the top is absolutely flatThe diameter of the disk 32.1mm on top and the underside edge is radiused. The plate is 5mm thick..
    The legs that are part of the same casting are rectangular at the top and bottom, but the sides and ends taper in downwards.
    The top rectangle is 10 by 5mm, and this tapers down on all sides to 8.9 by 3.7 on the underside , over a leg height of 10.3mm.
    I have done a sketch of it with dimensions as above,. It definitely should have a roll of brass gauze in the lipstick tube.
     

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