7mm Stretcher bars - advice please

Discussion in 'Permanent Way' started by NewportRod, 8 June 2020.

  1. NewportRod

    NewportRod Active Member

    As a relative newbie to 7mm (and Scaleseven) could i elicit advice on stretcher bars please? I am looking for something suitable for pre-grouping bullhead hinged blades.

    I notice there was some discussion eight years ago on these pages but I wondered if things had moved on.

    In 4mm I have been happy with the Masokits and (decades ago) Ottowan offerings.
     
  2. ChrisBr

    ChrisBr Active Member

    Rod,

    Not sure there's too much commercially for pre-grouping, I have developed these for my own Edwardian GWR use...

    upload_2020-6-8_18-53-29.jpeg

    Excuse the base, it is just a prototype to prove the concept...
     
  3. Stevesopwith

    Stevesopwith Western Thunderer

    Hi Chris, those look excellent... would you tell us how you made them.
     
  4. ChrisBr

    ChrisBr Active Member

    Steve,
    A mix of 3d print and brass castings as seen below -
    upload_2020-6-12_18-52-15.jpeg
    upload_2020-6-12_18-52-38.jpeg
    the following shows how the front stretcher bar is constructed -
    upload_2020-6-12_18-56-11.png upload_2020-6-12_18-56-33.png

    which ends iup with something like this -
    upload_2020-6-12_18-57-46.png

    the plan being that the switch is driven from a servo underneath driving the rodding crank...

    The weak link is obviously the 3d plastic print but that provides the required insulation. As I am planning to use battery powered RC in future, I may well make the front stretcher all brass and improve its strength, although I have to say it is reasonably robust as seen above based on usage so far.
     
  5. Stevesopwith

    Stevesopwith Western Thunderer

    Thanks Chris, very interesting, and they could be useful on my 'other layout'.

    I'll send a PM.

    Steve.
     
  6. NewportRod

    NewportRod Active Member

    Thank you for the pics Chris, they very much look the part.

    I'm planning to use BPRC myself but will probably want to allow track to be powered for visiting stock.

    R