SpeedTrap - 'Curved Version' N Scale Speedometer....

Curved version of the SpeedTrap speedometer that can be placed on a 'curved' (12.5" radius) section of N scale track and used to measure the loco's speed in MPH or KPH. There is also a straight version here....

https://www.thingiverse.com/thing:6701840

Much more about it with pictures, parts list and how to build it here....

https://1fatgmc.com/RailRoad/DCC/page-30.html

A video of how it works here....

https://www.youtube.com/watch?v=oAGohxnNBME

Another video of the 'straight' and 'curved' SpeedTraps next to each other...

https://youtu.be/25tOs9-My9U

A video showing the MPH and KPH options.....

https://www.youtube.com/watch?v=S4EAnjUjnb0

You can find other 3D printable parts for your layout here....

http://1fatgmc.com/RailRoad/RR%20Main/Railroad-Index.html