drM Speedometer

This easy to use model rail Speedometer is available from our online store.
Trackside Speedometer for G/1/O/HO/OO/S/N/Z scale, supporting multiple countries differing scale ratios and showing units in Km/h or mph.
Sitting alongside your track, this is the easy way to see the scale speed of your trains.
This unit stands beside any track, and displays the speed of a train as it passes, in either direction.
It is a stand-alone device, and runs off 5V USB power, and is ideal for DC or DCC layouts.
We also offer an optional USB power bank for situations where other power sources are not convenient.

The speedometer uses the precision of a microcontroller to measure the time between two infrared beams that the train passes through. Based on this time, the scale speed can be calculated from a mathematically derived calibration factor.
Built into the software are the calibration factors for US (1:160) and UK (1:148) N scales, US H0 and British 00, and these factors are selectable from a button accessible from the front panel of the device.

Speed is displayed for ~3 seconds and then unit goes into "Detect speed" mode again.
Auto shut off after 10 minutes (selectable) of no trains.

Click here to order your new drM Speedometer.
Select the built-in sensors or add on the optional remote sensor unit.
Includes the USB A to mini power cable; add our optional 5V 10000mA USB power block.

The unit can sit beside a track, or an optional remote sensor unit can be placed into less accessible locations.
Seen here measuring 22.3 MPH for this N Scale freight train.

See our Application Note for using this Speedometer to help set up speed-matching of locos with SPROG.