... you use the 3-point track gauges. If you won't be going as tight as that on radius you probably don't need any gauge-widening. RTR models are made to run on curves down to around 18"/ 450mm radius at 16.5mm, so will easily run round 30"/ 750mm at 16.2mm. You can see the smallest radius in a turnout on the info display in Templot. A6 and B7 are well within the allowable range. Here is the info for an A-6 in 00-SF: 2_091811_330000000.png Showing that even with a regular V-crossing the smallest radius is around 36"/ 900mm and no gauge-widening would be needed. If you go below 1:6 it is better not to use size "A" switches, use a 9ft switch instead, and change the V-crossings to generic or curviform. This will ease the radius and keep it well within the safe range, and also save some space. regards, Martin. posted: 10 Feb 2015 11:17 from: TPP Thanks ...