Disclaimer

Everything on ModelRailCalc is researched guidance, not professional advice. It is compiled from published manufacturer specifications, instruction manuals, published NMRA standards and recommended practices, and the consensus of verified owner reviews. We do not test products in person and we never claim to.

Standards against rules of thumb

This distinction runs through the whole site and it matters more here than the general disclaimer does.

Some figures are sourced and exact. Scale proportions and track gauges follow NMRA Standard S-1.2. Car weights follow NMRA Recommended Practice RP-20.1. Copper resistance by wire gauge comes from standard wire tables. Grade, frog angle, ladder geometry, areas and volumes are plain arithmetic, and every calculator shows its working so you can check it.

Some figures are hobby convention. Minimum radius as a multiple of car length is the clearest example: it is widely used and it predicts real behaviour well, and it is not a standard. NMRA Recommended Practice RP-11 is the standards-body document on curvature and rolling stock. Typical locomotive current draw figures are planning numbers, not specifications.

Wherever a figure is a rule of thumb, the page says so. A manufacturer's stated figure for a specific model always takes priority over any general rule on this site. If the box says the locomotive needs a 22 inch radius, it needs a 22 inch radius, whatever our arithmetic suggests.

Check it against your own equipment

Manufacturers vary, tolerances vary, and what your specific models will accept varies. Before cutting wood, laying rail or committing to a track plan, test the actual equipment you own on the actual geometry you are planning. A temporary curve laid on the floor costs an afternoon; a permanent one that will not run your locomotive costs the layout.

Electrical work

The low voltage side of a model railroad, meaning the track, the bus, the feeders and the decoders, is safe to work on and is what this site covers.

Mains electricity is not. Adding sockets, fixed lighting or any permanent wiring to a layout room is work for a licensed electrician, carried out to your local code. Never modify the mains side of a power supply, and replace a damaged supply rather than repairing it. Nothing on this site should be read as guidance on mains wiring.

Tools, materials and children

Cutting plywood, using a soldering iron, spraying paint and working with adhesives and plaster all carry ordinary workshop risks. Use eye protection, ventilate the space, and follow the manufacturer's instructions for any product, which take precedence over anything written here.

Model trains are not universally suitable for young children. Manufacturers print age ratings on the packaging and those ratings reflect small parts and other hazards. Follow them rather than our general comments about which scales survive handling.

Prices and availability

Every price shown is the listed price at the time the page was compiled and changes constantly. Treat any total on this site as a planning figure rather than a quote, and confirm the current price before committing to a purchase or budgeting a whole layout around it.

No warranty

This site is provided as is. We make no warranty as to the accuracy, completeness or fitness for any particular purpose of the information here, and we accept no liability for any loss or damage arising from its use. You are responsible for verifying anything that matters before you act on it.

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