Model Railway Forum

Help please, has anybody any suggestions for how to curve card for a curved corner on a scratch built building please?
My requirement is for about a quarter circle something approximately the diameter of a yoghurt carton.
Any ideas on how I may be able to do it please?

Just curve it over what ever curve you require. Cardboard is easy to curve as long as it isn’t corrugated. Cut some card formers to glue inside the curve if necessary.

If you take some card and bring the two edges together it will form a curve unless you purposely crease it.

If you have something like a rolling pin, use that as a mandrel and gently bend the card sliding it across the mandrel forwards and backwards so as to apply the pressure at different points. Once you have a smooth curve even if not the correct curve, then as WTD has said use curved formers glued inside to keep the curve you require.

Then as quickly as you can replace the rolling pin before domestic management sees you with it. Other things that might serve as a mandrel of about the same size would be a piece of drainpipe. The thing is not to get a crease in the card.

Richard

Thank you for those suggestions, thinking about it, a baked bean or soup can will not be far off what I need.

Why not use an alternative method, cut a section out of a card tube, section of plastic pipe or even a section of a bean can. You are scratch building so think outside of the box. Go Blue Peter and cut a toilet roll tube and open it out.
Just a few suggestions,
Plastic pipe can be manipulated when heated with hot water, Even a cheap plastic container could be cut up.

I am intregued!

As yoghurt cartons come in a variety of size (and shapes) why not use one of the appropriate shape?
(Eat the contents first though!)

I employ the rolling pin method using a suitably sized mandrel. You can achieve the same effect by drawing the card over a rounded edge, say a table top or other bit of furniture. The technical method is to put it back and forth through a mangle - two adjustable rollers. Unfortunately not too many of those around these days, but you could make a model sized one from broom handle or dowel offcuts, a simple frame with a slotted adjuster for one roller and some screws and washers.

Curving cardboard is what it does naturally. If you put a piece of cardboard in to a gap and it is longer than the gap it will curve so it fits. Does it on its own.