Small roller wheels for 7 1/4" gauge model railways

thingiverse

These wheels are intended for use under 7-1/4” (or 7-1/2”) gauge models of modern light-rail trams, Talgo car sets etc. WARNINGS Use at your own risk. Not to be used for carrying passengers. Also not suited to powered or braked wheel sets. The strength of each print is unknown but is unlikely to more than the load rating of the commercial castor upon which the design is based, typically 40Kg. So even if the rail wheel is as strong as the original plain wheel, a pair of them would not be enough for most adults, allowing a little for the car structure. However, when used under non passenger scale models of modern trams (or other rolling stock that uses small wheels) these wheels are unlikely to be overloaded. Another use is for a simple mobile platform for holding the toolbox during track maintenance. It is easier to start with an available castor assembly and adjust the wheel design to suit than to make a wheel and then try to find a suitable castor. The OpenSCAD source is provided so you can make adjustments. The flange shape is based on the public AALS standard wheel profile ( https://www.aals.asn.au/wp-content/uploads/2019/12/7-14-inch-gauge-track-wheel-standards.pdf ) and should be retained. If necessary, the width of the new wheel should be adjusted to match the plain wheel being replaced. Similarly, the diameter could be adjusted up or down so that the flange does not foul the bracket. Measure the existing axle bolt and adjust the hole in the new wheel to match. (A 15/64” drill bit comes in handy sometimes.) As many of the original plain molded wheels are solid, I suggest that the new wheels are printed with 100% in-fill. However, I have also included a spoked wheel for anyone interested. Please consider the wear on these wheels. Under a model on your home railway, they might do a kilometre or less per month , but on a big club track they might go 20 times as far. So, check for wear from time to time and if necessary, remake the wheels with cavities for small ball bearings. Again, the OpenSCAD source will be useful. Finally, if you “remix” and publish your improved implementation of these wheels (and I hope you do!) then you must include similar safety warnings in the instructions.