Tony Davis Posted June 8, 2013 Share Posted June 8, 2013 Anyone had any experience of using those flexible curve things they sell in art shops? I have finally got out of my armchair and started to build a layout. I am building a dockside layout with inset rails using card covered with scalescenes papers. I am struggling to cut out the bits for the 4 foot as it goes around a curve and thought I could "trace" the shape with the flexible curves and draw it onto card. Is the flexible curve stiff enough to hold the shape if I lift it off the track and lay it on the card and draw against it? thanks Tony Link to post Share on other sites More sharing options...
RMweb Gold 96701 Posted June 9, 2013 RMweb Gold Share Posted June 9, 2013 Anyone had any experience of using those flexible curve things they sell in art shops? Is the flexible curve stiff enough to hold the shape if I lift it off the track and lay it on the card and draw against it? thanks Tony Yes and yes. The one I had many moons ago held it's shape very well. It was very similar to this http://www.amazon.co.uk/KOH-I-NOOR-Koh-I-Noor-Flexible-Curve-30cm/dp/B001G06ZOS/ref=sr_1_1?ie=UTF8&qid=1370767374&sr=8-1&keywords=flexible+curve Link to post Share on other sites More sharing options...
trisonic Posted June 9, 2013 Share Posted June 9, 2013 Strictly speaking French Curves are not those flexible things - but are very useful too. Best, Pete. Link to post Share on other sites More sharing options...
shortliner Posted June 9, 2013 Share Posted June 9, 2013 In my youff, "French Curves" refered to La belle Brigitte Bardot Link to post Share on other sites More sharing options...
trisonic Posted June 9, 2013 Share Posted June 9, 2013 That too. I always preferred "Italian Curves" frankly - I thought Sophia had better legs... But we digress. Btw Jack are French Curves particular mathematical formulas like Fibonacci Spirals? I never finished Art School... Best, Pete. Link to post Share on other sites More sharing options...
buffalo Posted June 9, 2013 Share Posted June 9, 2013 ...are French Curves particular mathematical formulas like Fibonacci Spirals? I never finished Art School... Euler or Cornu spirals, see here or here. Apparently the same concept may be used to calculate transition curves in track. Nick (who used french curves many years ago but didn't actually know this until he looked it up...) Link to post Share on other sites More sharing options...
shortliner Posted June 9, 2013 Share Posted June 9, 2013 I honestly wouldn't know, Pete - I never could get my head around how to use them - I use an old Helix flexible curve, so old that I ought to replace it. The only thing I know about Fibonacci series is that they start with 0 and increase by adding the the previous number to it, eg 0, 1, 1, 2, 3, 5, 8,....... as an example For those interested see http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fib.html Link to post Share on other sites More sharing options...
Tony Davis Posted June 9, 2013 Author Share Posted June 9, 2013 Yes and yes. The one I had many moons ago held it's shape very well. It was very similar to this http://www.amazon.co.uk/KOH-I-NOOR-Koh-I-Noor-Flexible-Curve-30cm/dp/B001G06ZOS/ref=sr_1_1?ie=UTF8&qid=1370767374&sr=8-1&keywords=flexible+curveI Thanks for that. I will go and buy one. Tony Strictly speaking French Curves are not those flexible things - but are very useful too. Best, Pete. I thought that might be the case but I wasn't sure what the proper name was. Link to post Share on other sites More sharing options...
Tony Davis Posted June 9, 2013 Author Share Posted June 9, 2013 In my youff, "French Curves" refered to La belle Brigitte Bardot I did sub-title the post "not Brigitte Bardot" but it doesn't seem to appear :-) Link to post Share on other sites More sharing options...
shortliner Posted June 9, 2013 Share Posted June 9, 2013 The other tool is one of those holders full of needles that you press against a curve - the needles adopt the shape and peovice a perfect inside and outside template of the item being copied They are called Contour profile gauges http://en.wikipedia.org/wiki/Profile_gauge Not expensive - here is one on Ebay Item number: 400502849031 Link to post Share on other sites More sharing options...
Gruffalo Posted June 9, 2013 Share Posted June 9, 2013 I did sub-title the post "not Brigitte Bardot" but it doesn't seem to appear :-) Catherine Deneuve did it for me. To paraphrase Eric Morecombe, Bridgit had all of the curves but not quite in the right places whereas Mme Deneuve... and she is still a very attractive woman drawing her OA Pension! Must go and have a cold shower now to get rid of the lascivious dribblings! Ah, the other french curves. As Trisonic mentions, these are varying radii templates. What you need is a flexible edge and you can then set it to the shape you need, transfer it (with care) and draw the required shape using it as a template. Link to post Share on other sites More sharing options...
RMweb Gold SHMD Posted June 9, 2013 RMweb Gold Share Posted June 9, 2013 Another option is to use a long piece of “springy” shim steel. Like a 1m steel rule but thinner so that it is a bit more flexible. To use it get a flat board (lets say 0.5m by 1m) and draw, to scale, the track plan at the entry and exit points on the board. Next, place the shim steel on the board (edge on) and bend the shim steel so that the steel enters and exits the board with the (unsupported) overhanging ends following the desired track path entry and exit points. (It is easiest to pin the shim to the board, at this stage, to achieve this. Basically, pins will be needed where you are currently trying to hold it!) You will then find that the shim has “naturally” followed the “best course” between the 2 points on the board. This then allows you to adjust/coax/change the natural curve, that the shim tries to take, by adding a further pin (or two) at a points the the curve must take en-route. But this is optional and depends upon local constrictions/obstacles! Once satisfied, use a pencil, to make out the centre line that the track must take. It is easier to do than explain but the result will be naturally flowing curves within the space required. A Flex-Rule was used to (crudely) transfer, or copy, an already existing curve. French Curves are mainly for generating new smooth changes in radii of curves. But, of course, anything goes here and every bodies experience differs. Kev. (Who hasn't seen his “flexible” ruler or “french curves” set for quite some time now!) Link to post Share on other sites More sharing options...
Tony Davis Posted June 9, 2013 Author Share Posted June 9, 2013 This is what I was thinking of: http://www.amazon.co.uk/Linex-Flexible-Curve-Graduation-30cm/dp/B0027J3HX4/ref=sr_1_2?ie=UTF8&qid=1370777242&sr=8-2&keywords=Linex+flexible+curve, as suggested by Phil. I am off to hobby craft in a few mins to get one.Got to be back for the Canadian GP at 5. Also tape set for Beeching night tonight Link to post Share on other sites More sharing options...
Tony Davis Posted June 9, 2013 Author Share Posted June 9, 2013 I honestly wouldn't know, Pete - I never could get my head around how to use them - I use an old Helix flexible curve, so old that I ought to replace it. The only think I know about Fibonacci series is that they start with 0 and increase by adding the the previous number to it, eg 0, 1, 1, 2, 3, 5, 8,....... as an example For those interested see http://www.maths.surrey.ac.uk/hosted-sites/R.Knott/Fibonacci/fib.html Snails use the Fibonacci sequence to build their shells Link to post Share on other sites More sharing options...
RMweb Gold SHMD Posted June 9, 2013 RMweb Gold Share Posted June 9, 2013 A good example of a "Flexi-curve" as it shows that 'sharp kinks' can be produced. Kev. (BTW who was admiring some French curves in Paris recently, but don't tell the misses!) Link to post Share on other sites More sharing options...
BG John Posted June 9, 2013 Share Posted June 9, 2013 The other tool is one of those holders full of needles that you press against a curve - the needles adopt the shape and peovice a perfect inside and outside template of the item being copied They are called Contour profile gauges http://en.wikipedia.org/wiki/Profile_gauge Not expensive - here is one on Ebay Item number: 400502849031 They're good for very short curves. I used one to put matching reverse curvy ends on some 8"x2" timber, but had to mark it in two goes. I'm not sure they'd be very good for getting a smooth curve for a length of track. Link to post Share on other sites More sharing options...
shortliner Posted June 9, 2013 Share Posted June 9, 2013 I was thinking of it more towards being used for Fill-in pieces for inset trackage, than for aligning trackage curves Link to post Share on other sites More sharing options...
Tony Davis Posted June 9, 2013 Author Share Posted June 9, 2013 I was thinking of it more towards being used for Fill-in pieces for inset trackage, than for aligning trackage curves That is what it would be used for. Link to post Share on other sites More sharing options...
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