Another bridge too far

Discussion in 'Members Personal Layouts' started by paul_l, Feb 8, 2018.

  1. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    Viola...?? Where's the strings...?? :avatar::avatar:

    Cheers, Gary.
     
  2. paul_l

    paul_l Staff Member Administrator

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    A little more done today

    Dowels and T nuts fitted to the first center board



    Tomorrow the other board - I hope

    Paul
     
  3. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    Coming on. very neat work ....... go to the top of the class. ....... for more homework. :avatar:
     
  4. jakesdad13

    jakesdad13 Staff Member Moderator

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    I have used T nuts on my new boards for the leg struts, but I use over centre clips to hold the boards together as they allow a little wriggle room if things don't quite line up plus I don't need to crawl under the boards to fit bolts. With my knees and back I need all the help I can get :giggle:.

    Pete.
     
  5. paul_l

    paul_l Staff Member Administrator

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    Hopefully Pete the alignment dowels will stop all wiggling, must make me some from of control freak :avatar:

    Paul
     
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  6. paul_l

    paul_l Staff Member Administrator

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    Finally got time to do the other board


    The foam is not glued in place just yet - I'm sculpting access to the bolts


    Paul
     
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  7. paul_l

    paul_l Staff Member Administrator

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    Both foam sheets fettled to shape and glued in place with Gorilla glue, a thin coat of glue applied to the expanded polystyrene insulation board, and the wooden frames wetted before inserting the foam sheets, and weighting them down. As the glue expands to 3 to 4 times its thickness, it makes the board quite rigid.

    A word of warning, make sure your wearing old clothes and protective gloves, this is not the most pleasant of glues to work with, but at least its oudourless.

    Now need to get timber to support the track bed.

    Paul
     
  8. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    yeah ....... stop monkeying around. :avatar:
     
  9. paul_l

    paul_l Staff Member Administrator

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    A little progress made, started the track bed for the first board

    12mm ply 80mm wide, with two 15mm x 6mm stripwood as braces.


    Once the glue is dry, I'll be able to remove the fixing screws and sand the faces, then secure the other end.

    Paul
     
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  10. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    Coming along Paul. Neat work.
     
  11. paul_l

    paul_l Staff Member Administrator

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    Bit more progress, waiting for some bits to dry so a bit of dry testing

    I've stacked 3 x 50mm foam boards on the right hand board - unfortunately its approx 8 mm too high, so I will need to cut three lengths the correct height and glue them together


    View from the end of the bridge section towards the points and fiddle yard


    Same direction but from the end of the bridge


    The expanded polystyrene foam insulation boards


    Paul
     
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  12. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    The Anyrail print offs are handy for giving an impression of the track layout. I can see some of them being printed off. Same with the 145mm back to backs.

    Cheers

    Toto
     
  13. Gary

    Gary Wants more time for modelling.... Staff Member Administrator

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    The great thing about the foam is that it can be filed back with a Surshape Shaver to any shape, height/depth you want.

    Trojan surshape shaver.jpg

    When sculpting the landscape, try not to have the ground surface dead flat coming off the bridge, that looks so unnatural. :thumbup:

    Cheers, Gary.
     
  14. paul_l

    paul_l Staff Member Administrator

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    A little more progress this evening

    The timber section for baseboard 2 now fits, and the foam cut to accommodate the timber section.



    This section will be girders bridging from the main bridge to land, I will clad it in either plasticard or card, I have some laser cut lattice sides on order, and hope to build something in the style of this

    [​IMG]

    Probably with only one span.

    One set of turrets here


    And the lattice will be here.

    Also put on order from MERG, a 5A booster, the idea being I can power the track bus from the MERG booster, the command station still being a NCE powercab, so Toto will be able to run his Heljan and brass loco's without having to bring his power pro along.

    Paul
     
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  15. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    Better get the sound fitted to the class 37 then. :avatar:
     
  16. paul_l

    paul_l Staff Member Administrator

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    Spent a good deal of the day waiting for glue to dry - which is taking longer than normal, as the boiler has decided to go on strike.

    PVA applied to the two track foam boards, these were temporarily held in place with German pins - that's what it said on the label.


    These were inserted in to the boards either at an angle or across a joint to hold them in place.


    and looks like this


    I'm trying clay on top of foam then applied the Bricks roller, these will form the stone supporting piers.



    I have had to add weights as they have started to curl while drying. :facepalm:

    We'll see tomorrow how they turnout.

    Paul
     
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  17. paul_l

    paul_l Staff Member Administrator

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    Two sides assembled and the foam cut away to fit.


    Just wedged in place at the moment

    Paul
     
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  18. Toto

    Toto I'm best ignored Staff Member Founder Administrator

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    The moulding looks very good Paul. Maybe the 11 inch roller would be worth considering in order to be able to get bigger seamless sections. Colouring should be flexible as well. I' m looking forward to seeing a decent size section painted / weathered. :thumbs:

    Cheers

    Toto
     
  19. Chatty

    Chatty Full Member

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    Good work Paul.

    Interesting use of foam. Love the photograph of the Tay Viaduct.

    A friend of mine is building a similar bridge that traversed Murrumbidgee River at Wagga. His blog is at http://buildingwagga.blogspot.com.au/ and scroll down to the start of the blog.

    Kind regards

    Geoff
     
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  20. paul_l

    paul_l Staff Member Administrator

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    Hi Geoff

    The foam has turned out to be not so good, as the outer surface shrank and them bit didn't, so either curved, when weighted down cracked



    A good representation of some serious structual weaknesses, but probably not a good sight on a bridge support :facepalm: :avatar:

    I will go back to my first attempt using a piece of ply wrapped in cling film.

    What was that old saying - if at first you don't succeed - give up :avatar:

    Paul
     

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