RollBy™ OnBoard Speedometers

For Android SmartPhones & Tablets

For Apple iPhones & iPads


The Local

Colorado & Southern Ry. Engine 629 drifts past Renick siding with the southbound Local.   In 1958, steamers still service the industries between Denver and Cheyenne.

Ever wonder how fast your train is really going… in that tunnel?

Or how long your Main Line is from one end to the other?

What about the mileage from Union Station to Burns Junction?

Do you ever wish you could keep an eye on all the speed-demon engineers on your layout — in a single glance?

The RollBy™ OnBoard Speedometer turns your SmartPhone or Tablet into a dashboard speedometer for your trains — and it accurately measures distances on your layout too!

The OnBoard Speedometer installs easily in any railcar on your layout and sends speed and distance data to the free RollBy™ Train Speedometer App on your mobile device while the car's moving.



This video demonstrates the RollBy™ OnBoard Speedometer and the RollBy™ Train Speedometer App — including how to download the App from the Google Play Store or the App Store to check your SmartPhone's compatibility.

Train Speed & Distance Sensor for Smartphones & Tablets

  • Transmits speed and distance to your Android Smartphone/Tablet or Apple iPhone/iPad
  • Display with free RollBy™ Train Speedometer App
  • Continuous speed (3 MPH – 200 MPH) and distance from any railcar
  • Perfect for measuring distances on your layout
  • App tracks more than one OnBoard Speedometer simultaneously
  • Requires Android 4.3 or iOS 9.0 or greater with Bluetooth Low Energy

Simple installation

  • Circuit board fits standard gauge cars in N Scale, all cars in HO and larger scales
  • Connect button cell battery (included) with circuit board jumper
  • Replace existing railcar wheelset with Rotation Wheelset (included)

Included parts:

  • RollBy™ OnBoard Speedometer Circuit Board, battery included
  • Rotation Wheelset with cylinder magnet
  • Stainless steel screw (HO Scale only)
  • Product Manual

BEFORE YOU ORDER…

Google Play

Be sure your SmartPhone is Bluetooth Low Energy (BLE) ready BEFORE you order your RollBy™ OnBoard Speedometer!

  • Download and install the RollBy™ Train Speedometer App from the Play Store or App Store.
  • Run the App to check your device software and its BLE compatibility.
  • Upgrade your mobile device software if necessary.
  • The App Welcome Page will display when your device is BLE ready — now you can order your Onboard Speedometer with confidence!

Please confirm before ordering:

I have successfully installed and run RollBy™ Train Speedometer App on my mobile device.

OnBoard Speedometer — HO Scale 33" Wheels

RollBy™ HO Scale 33 Inch Wheelset

  • Includes:
  • RollBy™ OnBoard Speedometer Circuit Board for HO and Larger Scales
  • HO Scale 33" standard gauge Rotation Wheelset (built from Intermountain Railway Co. all-brass insulated wheelset)
  • Stainless steel screw

Model No. RB-21-HO33   $79.95  



OnBoard Speedometer — HO Scale 36" Wheels

RollBy™ HO Scale 36 Inch Wheelset

  • Includes:
  • RollBy™ OnBoard Speedometer Circuit Board for HO and Larger Scales
  • HO Scale 36" standard gauge Rotation Wheelset (built from Intermountain Railway Co. all-brass insulated wheelset)
  • Stainless steel screw

Model No. RB-21-HO36   $79.95  



OnBoard Speedometer — N Scale 33" Wheels

RollBy™ N Scale 33 Inch Wheelset

  • Includes:
  • RollBy™ OnBoard Speedometer Circuit Board for N Scale
  • N Scale 33" standard gauge Rotation Wheelset (built from the recently-released Intermountain Railway Co. High Detail Brass Insulated Wheelset)

Model No. RB-21-N33   $79.95  



OnBoard Speedometer — N Scale 33" Micro-Trains® Wheels

RollBy™ N Scale 33 Inch Micro-Trains® Wheelset

  • Includes:
  • RollBy™ OnBoard Speedometer Circuit Board for N Scale
  • N Scale 33" standard gauge Rotation Wheelset for Micro-Trains® (built from Intermountain Railway Co. High Detail Brass Insulated Wheelset to fit Micro-Trains® Trucks)

Model No. RB-21-N33MT   $79.95  



OnBoard Speedometer — O Scale 33" Wheels

RollBy™ O Scale 33 Inch Wheelset

  • Includes:
  • RollBy™ OnBoard Speedometer Circuit Board for HO and Larger Scales
  • O Scale 33" standard gauge Rotation Wheelset (built from an Intermountain Railway Co./Atlas O all-brass insulated wheelset)

Model No. RB-21-O33   $89.95  



OnBoard Speedometer — Large Scale 31mm Wheels

RollBy™ G Scale 31mm Wheelset

  • Includes:
  • RollBy™ OnBoard Speedometer Circuit Board for HO and Larger Scales
  • G Scale 31mm Rotation Wheelset (built from a Bachmann 31mm diameter / 45mm gauge insulated wheelset)

Model No. RB-21-31mm   $99.95