Product Catalog

RollBy™ OnBoard Speedometers


N Scale InstallationRollBy™ OnBoard Speedometer turns your SmartPhone or Tablet into a dashboard speedometer for your trains — and it accurately measures distances on your layout too! It fits easily into an N Scale car as shown here.

Download the free RollBy™ Train Speedometer App from Google Play Store or the App Store to display speed and distance on your Android or Apple mobile device. It's perfect for measuring distances on your layout, and tracks more than one OnBoard Speedometer simultaneously.

Google Play

The App requires Android 4.3 or iOS 9.0 or greater with Bluetooth Low Energy capability.


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

Please confirm before ordering an OnBoard Speedometer:

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  



HotShot™ Trackside Speedometers

HotShot™ Speedometer           Model No. HS-31

HotShot™ SpeedometerHotShot™ Speedometer displays scale speed for each passing train. The display flashes and an alarm sounds for trains over the Speed Limit (set by the user) — just like a highway speed trap!

The Speedometer sports a bright red 7-segment LED readout with 0.55" high digits. A single button push displays speed records and other statistics.

Includes: HotShot™ Speedometer Faceplate/Circuit Assembly, 2 Photo Sensors, Fascia Template, Product Manual.

Model No. HS-31   $79.95  


Watch this video demonstration of HotShot™ Speedometer in action.

NightScope™ IR Detectors   Model No. NS-2350 (Special 2-Pack for Speedometers in Dim Light)

NightScope™ Instant ResponseTwo NightScope™ Infrared Detectors must be used instead of the HotShot™ Photo Sensors for dim or no light conditions only. Typical room lighting conditions do not require Infrared Detectors.

2 Pack of NS-350   $39.90  



BrassHat™ Announcers & Sound Recorders

Announcer                             Model No. BH-21A

BrassHat™ AnnouncerA recordable sound module with a fascia faceplate, Announcer has 5 pushbuttons to trigger up to 10 separate messages and sounds. A pre-recorded "outdoor crowd" background track is included, along with the standard user-recordable background track.

Announcer is the perfect choice for fascia-triggered announcements for passenger stations, yards and industries. These can be mixed with background and automatic sound playback.

Includes: BrassHat™ Announcer Faceplate/Circuit Assembly, 3 minute 36 second recording capacity, Fascia Template, Product Manual.

Model No. BH-21A   $119.95  


Sound Recorder                   Model No. BH-21SR

BrassHat™ Sound RecorderSound Recorder records and plays back up to 8 separate messages and sounds, along with a user-recordable background track.

Trigger playback with pushbutton switches (not included), other connected electronics, or by built-in automatic playback options.

Includes: BrassHat™ Sound Recorder Circuit Board, 4 minute recording capacity, Vinyl Tubing for Standoffs, Product Manual.

Model No. BH-21SR   $89.95  


Watch this video demonstration of BrassHat™ Recordable Sound Modules.



TrainBoss™ Defect Detectors

Talking Defect Detector     Model No. TB-23F/M

TrainBoss™ Talking Defect DetectorModeling defect detectors of all eras, the Talking Defect Detector speaks and displays 6 types of defect alarms for passing trains with the probability you assign in either male or female voice. The Talking Detector also reports axle count, train speed and length, and temperature — just like automated detectors on the prototype. For a bygone era, listen as rear trainmen report defects and speeding engineers. The Talking Detector can also be configured as a Displaying Detector. Speakers and Display Bezel not included.

TrainBoss™ Defect Detector can be configured for a single track location, with axle count, speed, and length reporting that matches modern prototype detectors. The Detector's two Axle Sensors can also be installed to cover a double track main line or two widely-separated single track locations, with axle count only — two detectors in one! Or the Axle Sensors can be installed on track approaching bridges and tunnels to give high/wide load protection.

The Voice Chip of your choice (male or female) is included. Please order by voice type:

  Female Voice Model No. TB-23F   $149.95  

Male Voice Model No. TB-23M   $149.95  

Important: If your rail is larger than Code 125 (1/8"), please let us know. We will provide longer LED leads on your Axle Sensors.



Watch this video demonstration of TrainBoss™ Defect Detector in action.

Custom Word or Phrase         Item No. TB-CWP

Boulder Creek Engineering is happy to add a word or phrase that's special for your railroad. We'll record and add it to the more than 120 words and phrases already included with the TrainBoss™ Talking Defect Detector. And we'll load it on as many Talking Defect Detectors as you order.

Custom words or phrases must be ordered separately for each automated voice type, male and female, if both are desired. For example, "Colorado and Southern Ry." in both male and female voice would be two orders of that phrase for a total of $20.

Be sure to include your email address with your order so we can contact you for pronunciation or other questions.

Custom Word or Phrase (60 letters max.):

Item No. TB-CWP   $10.00 each  

Voice Chip                         Item No. TB-VC22F/M

TrainBoss™ Voice ChipYou can change the automated voice on your Model No. TB-22F/M Talking Defect Detector from male to female or vice versa by swapping the Voice Chip.

Please order an additional Voice Chip by automated voice type:

Female Voice Chip Item No. TB-VC22F   $30.00  

Male Voice Chip Item No. TB-VC22M   $30.00  

Upgrades                     Item No. TB-UG2223F/M
                                    Item No. TB-UG2123F/M

Customers who desire the latest features and vocabulary can upgrade their current Talking Defect Detector to Model No. TB-23F/M. You must send your Talking Defect Detector circuit board postpaid to Boulder Creek Engineering and order the desired upgrade below.

If you are upgrading to the opposite gender voice with Custom Words or Phrases, (for example, you have custom words in a male voice model and are upgrading to a female voice model) you must reorder your Custom Words or Phrases separately, Item No. TB-CWP above. Existing custom words in the same gender voice do not need to be reordered.

Please order by original model number and final upgraded voice type. (For example, to upgrade a Model No. TB-22 to Model No. TB-23 with Female voice, order TB-UG2223F.)

  Upgrade 22 to Female 23, No. TB-UG2223F   $10.00  

  Upgrade 21 to Female 23, No. TB-UG2123F   $20.00  

Upgrade 22 to Male 23, No. TB-UG2223M   $10.00  

Upgrade 21 to Male 23, No. TB-UG2123M   $20.00  


Display Bezel                             Model No. BZ-25

TrainBoss™ Display BezelSmoked lens bezel installs in front of the TrainBoss™ Defect Detector display. This gives a clean look for fascia mounting.

Model No. BZ-25   $4.95  



WeighStation™ Track Scales

WeighStation™ Track Scale     Model No. WS-22

WeighStation™ Track ScaleWith two display modes representing railroad scales of all eras, the WeighStation™ Track Scale sports a bright red 7-segment LED readout with 0.55" high digits. Its quick weight display makes this scale is well suited for either static or weigh-in-motion operation. Includes one NightScope™ Infrared Detector.

Model No. WS-22   $109.95  


Watch this video demonstration of WeighStation™ Track Scale in action.



Infrared Detectors

Instant Response Detector     Model No. NS-350

NightScope™ Instant ResponseThe Instant Response Detector reacts to train arrivals and departures by immediately changing its outputs. This is the Detector for fast acting electronics that expect and can handle brief changes in detection, such as between railcars.

Model No. NS-350   $19.95  

10 Pack of NS-350   $179.95  

Delayed Response Detector   Model No. NS-352

NightScope™ Delayed ResponseThe red-jacketed Delayed Response Detector activates its outputs instantly when a train is detected. It will hold its outputs active for 2 seconds after the train departs. This prevents outputs from “bouncing” between active and inactive during gaps between railcars. The onboard LED still responds instantly, aiding installation and testing.

Model No. NS-352   $19.95  

10 Pack of NS-352   $179.95  

How to Order

We accept major credit cards for online shopping. Orders by mail are accepted with check or money order.