The main problem with that technique is that you need to measure across the middle of the track where there is a space. I guess that you could measure the inside and outside rail lengths and average the two figures. It should be possible with only one piece of track but your measurements need to be very accurate since errors will multiple. Obviously easier with several pieces of the same curved track but then by the time you get to 3 or 4 you probably have a quarter circle which should be easy to measure. Having said that when I tried it I found it hard to tell if I had 10' or 11' diameter curvesbobg said:There is a way to calculate the radius of a circle from a small part of it, say two or three pieces of track. I haven't got the formula to hand but it works like this.... measure a set distance straight across the curve (a cord), perhaps a couple of feet, and measure the off-set i.e. the distance from the centre of that cord to the curve. It is then possible to work out from that the radius. I'm sure the exactitudes can be found in Google.
Good thinking, that's how they lay curved tracks in the 1:1 world - offsets from a chord.bobg said:There is a way to calculate the radius of a circle from a small part of it, say two or three pieces of track. I haven't got the formula to hand but it works like this.... measure a set distance straight across the curve (a cord), perhaps a couple of feet, and measure the off-set i.e. the distance from the centre of that cord to the curve. It is then possible to work out from that the radius. I'm sure the exactitudes can be found in Google.