Earl Bathurst Posted January 28, 2013 Share Posted January 28, 2013 Bit of a silly question but i am going to ask it. I got a base board which is 12ftx 8ft and want a large sweeping curve to give it a main line look. Whats the best way of getting a smooth curve? In the past i have used track settas but only 24 inch or smaller but these dont give a big curve, not sure what size track setta i would need to get a large sweeping curve. Can anyone help me with the probelm. Scott Link to post Share on other sites More sharing options...
Torr Giffard LSWR 1951-71 Posted January 28, 2013 Share Posted January 28, 2013 Hi Scott, Have a play with Templot (free) you can create a perfect curve to your own desire. Dave Link to post Share on other sites More sharing options...
Earl Bathurst Posted January 28, 2013 Author Share Posted January 28, 2013 I have never had any joy with templot Scott Link to post Share on other sites More sharing options...
Gruffalo Posted January 28, 2013 Share Posted January 28, 2013 I have used XTrackad, finding it easier than Templot. You can do the same except transitions are not quite as good (at least my transitions aren't). I also use AutoCAD - a full blown CAD package in the 4-figure price bracket for work. This allows lovely transitions but you have to create every bit of detail such as sleepers, turnouts, frogs etc and that takes some time. I am not volunteering anyone but there are some guys on RMWeb who enjoy doing this sort of thing and may help if you ask. Link to post Share on other sites More sharing options...
RMweb Premium Physicsman Posted January 28, 2013 RMweb Premium Share Posted January 28, 2013 How large the curve radius is will be limited by where on your board you are going to put it and the angle through which you want the track to turn. For example: If you are going for a semicircle at the end of your board you could (allowing for clearances) realistically fit in a 42" radius, with 6" clearance outside of the track. If it's just an arc of a curve, you could make it larger. Whatever you do - use a range of tracksettas (36", 42", 48" and 60" are all useful) and design up a transition curve from your straight rail. If you'd rather not do that - a cheaper alternative is to use a ruler and a piece of string to set arcs of different radii. If you don't feel comfortable with a CAD programme, simply "play" with the curves on your flexitrack until you get something you like. If you're interested, have a look at posts 1210, 1249 and 1250 - for example, here... http://www.rmweb.co.uk/community/index.php?/topic/53448-kirkby-luneside-fiddle-yard-complete/page-49 This is SMP flexi laid using the range of tracksettas mentioned above. Typical radii are from 36" to 48" on the bends near the guards van. Hope this is of some help. Jeff Link to post Share on other sites More sharing options...
Jeff Smith Posted January 28, 2013 Share Posted January 28, 2013 What type of track are you going to lay - flexitrack can be pinned down on a temporary basis to construct your curves - single or double track? Link to post Share on other sites More sharing options...
Earl Bathurst Posted January 28, 2013 Author Share Posted January 28, 2013 Its going to be peco flexi and double track. Thank for that info will have a look through it now Link to post Share on other sites More sharing options...
brightspark Posted January 28, 2013 Share Posted January 28, 2013 I use maths and plot out my curves using trig. Much more accurate than a bit of string. Are you after a constant curve or a transition curve? Link to post Share on other sites More sharing options...
Earl Bathurst Posted January 28, 2013 Author Share Posted January 28, 2013 I think i prefer a constant curve so it looks like a mainline. i like curved mainlines. i dont mind a bit of stright on the track but a gentle curve as i possibly can. there will be 1 board where i will need to include a fiddle yard so will need the curve to run into the poin t work for the fiddle yard. Link to post Share on other sites More sharing options...
RMweb Premium Kris Posted January 29, 2013 RMweb Premium Share Posted January 29, 2013 Pop a nail in at the centre point of your curve then run a bit of string from it out to the edge. Attach a pencil then holding the string taught and the pencil upright you draw. Takes a little practice but it does work. Link to post Share on other sites More sharing options...
RMweb Premium jamie92208 Posted January 29, 2013 RMweb Premium Share Posted January 29, 2013 One very simple way is to buy a length of thin UPVC from a window or guttering supplier, probably longer than the board, then anchor the centre and bend the ends round to your desired end radius and go round it with a pencil. I saw this done very successfully with a 5m length, that could be coiled up for transport, to lay out a station on a sweries of gentle curves. Jamie Link to post Share on other sites More sharing options...
RMweb Gold Joseph_Pestell Posted January 29, 2013 RMweb Gold Share Posted January 29, 2013 Is the 12x8 baseboard solid (unlikely)? Or is there an operating well? If the latter, that will have a lot of influence on the curves that you can use and where. Since you are using Peco track, you will need to give some thought as to how pointwork will fit into the curves - but see the Grantham thread for some great advice about rejigging straight Peco pointwork. Link to post Share on other sites More sharing options...
Earl Bathurst Posted January 29, 2013 Author Share Posted January 29, 2013 The layout is 12x8 with an operating well. The point work which im going to use is going to play a big part of the curve will form and how it flows. I Might just get a few different track settas and try which works best, I might try the pencil method i have seen it done with a length of stick, string and pencil but this was a long time ago i seen this. Scott Link to post Share on other sites More sharing options...
RMweb Gold Joseph_Pestell Posted January 29, 2013 RMweb Gold Share Posted January 29, 2013 If you could post a basic trackplan and drawing showing the operating well, there is probably someone on here (not me, because I have not mastered it either) who could do that clever trick where you import it into Templot and then morph it. Link to post Share on other sites More sharing options...
Multiple identity account 2 Posted January 29, 2013 Share Posted January 29, 2013 What about tracksetta? Woudn't that work Link to post Share on other sites More sharing options...
Silver Sidelines Posted January 29, 2013 Share Posted January 29, 2013 I use maths and plot out my curves using trig. Much more accurate than a bit of string. Are you after a constant curve or a transition curve? My 'baseboards' are open plan construction using L girders. The nail and string approach does not work as there is rarely a piece of board available to stick the nail into. I had some big sheets of card left over from display boards and I plotted a selection of different radii curves using good old fashioned geometry to make my own curved templates. When laying flexi track I found it easier to lay the track over the centre line of the curve where it is visible, rather than trying to align one of the rails on top of the pencil marked curve. Just some thoughts Ray Link to post Share on other sites More sharing options...
LNER4479 Posted January 30, 2013 Share Posted January 30, 2013 Bit of a silly question but i am going to ask it. I got a base board which is 12ftx 8ft and want a large sweeping curve to give it a main line look. Whats the best way of getting a smooth curve? Hi Scott, Some (many!) years ago, I got an insight into how the civil engineer on the big railway does it (well, did it - before the computer age!) and have adapted this for my modelling needs. This is based around the use of versines, being a measurement of the rate of curvature. As the curvature gets larger, the versines get smaller (ie 1/R) and thus quite 'manageable'. If you're interested, you can read a little more about it on my thread, post #36. PM me if you want any more details. Works for me, but plenty of other good suggestions above You're never going to be short of suggestions on RMWeb! Link to post Share on other sites More sharing options...
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