Author Topic: BR Mk 1 (that old chestnut...)  (Read 3852 times)

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Offline Peaky 556

Re: BR Mk 1 (that old chestnut...)
« Reply #15 on: Sep 08 2016 10:15 »
Thanks for encouraging news Geoff. And thanks Andy for the contact in Derby, I have made an approach and am awaiting their interest. I propose to send in a test piece file first, to see how the window and glazing bars would look in, say, 1mm ply as a starter for ten, with a view to making thicker if necessary.  All I need now is a window drawing!
I'm looking forward to this project, but am still looking for a partner to speed things up.
Regards, Tim

Offline Andy B

Re: BR Mk 1 (that old chestnut...)
« Reply #16 on: Sep 08 2016 15:28 »
All I need now is a window drawing!
I've looked and I can't find one of the main (4ft) windows. Sorry!
All I could find was a 2'3" toilet window, which was scarcely readable.
I think you'll need a trip to Butterley armed with a camera, tape measure & notebook.

I believe that you also need to choose your window frame type, as the orginal bodies suffered from corrosion and a variety of fixes, some with new frames, were applied.

Andy

Offline Geoff Nicholls

Re: BR Mk 1 (that old chestnut...)
« Reply #17 on: Sep 08 2016 19:39 »
when taking measurements, for some things like window corner radii, or door stops, you may find the brass rubbing technique useful. just hold a sheet of paper over the corner and go over it with a crayon. Better than a photo or a measurement, it's a permanent record you can re-examine at your leisure.
Geoff.

Offline Peaky 556

Re: BR Mk 1 (that old chestnut...)
« Reply #18 on: Oct 29 2016 08:48 »
Thanks guys, armed with a lot of measurements and photos, and a great deal of help from a Yahoo forum with the snappy title "British Railways Loco Hauled Coaching Stock Since 1948", I am ready to go.  I am undecided between some readily available steel sides (that would need rolling) and laser cut ply, but will try both.  Has anyone tried to roll coach sides?
I will report on progress, but it seems I am a lone operator so progress will not be fast!
Regards, Tim

Offline cabbage

Re: BR Mk 1 (that old chestnut...)
« Reply #19 on: Oct 29 2016 19:13 »
I will let you go first Tim... I am using laser cut ply. I am still not too sure if I should steam it or try to bend it cold and dry? This may involve building a steamer to take the coach sides.

Regards

Ralph

Offline MikeWilliams

Re: BR Mk 1 (that old chestnut...)
« Reply #20 on: Oct 29 2016 20:51 »
Tim,

I doubt you will be able to use the usual pinch rolls because for the length you'll need for a complete MK1 side the rollers will be quite large in diameter and not roll to the edge.  I think you would need to cobble something together, maybe using a fly press and some sort of strips to bend the side against.

My coach kits are etched brass and have horizontal half-etched lines along the lower part of the back.  It rolls easily by hand.  I wonder if you could in some way score such lines onto the back to help it bend in a straight line?

Mike


Offline Peaky 556

Re: BR Mk 1 (that old chestnut...)
« Reply #21 on: Oct 29 2016 22:01 »
Mike, interesting thoughts but they add unwelcome complexity. A friend is conducting some trials on my behalf with a wide rolling mill and one technique that is promising is to use a wider backing sheet and pass the two through together.  Only small samples have been tried so far, and I will be seeking advice from Walsall on how they built their coaches using these panels.  Anything more complex and I will be strongly tempted to change to thin ply. 

Ralph, what radius do your coach sides require?

Offline cabbage

Re: BR Mk 1 (that old chestnut...)
« Reply #22 on: Oct 30 2016 12:43 »
Tim,
According to the drawings the base of the coach side requires a radius of 75mm. The roof has a compound radius of 41mm at the edges and 91mm at the centre. I plan to make the roof from thin balsa and then laminate thin ABS sheet onto that.

Regards

Ralph

Offline Peaky 556

Re: BR Mk 1 (that old chestnut...)
« Reply #23 on: Oct 30 2016 13:00 »
Ralph, these radii are quite tight and for any ply thicker than 1mm I would suggest steaming it.

Offline Peaky 556

Re: BR Mk 1 (that old chestnut...)
« Reply #24 on: Dec 03 2016 14:18 »
Does anyone have suggestions for sourcing corridor connections? That could be commercial ones or good ways of making up from scratch.
Thanks, Tim

Offline cabbage

Re: BR Mk 1 (that old chestnut...)
« Reply #25 on: Dec 03 2016 15:13 »
Although he is "G1" and "G0" my friend Martyn makes his with wire formers and cut strips of duct tape. The formers are made from MIG welding wire and the duct tape is folded origami like so the outer parts go over the formers and the inner parts stick to it. Pleat a sheet of paper and the "hills" are the outside duct and the "valleys" are the inside duct.

I will do you a doodle later and mail it you.

regards

ralph

Offline Peaky 556

Re: BR Mk 1 (that old chestnut...)
« Reply #26 on: Dec 03 2016 20:12 »
Thanks Ralph, the idea is good, and I won't hold it against Martyn for not having seen the light yet!
Regards, Tim