The file 'SpeedTrap – ‘Straight Version’ N Scale Speedometer…. 3D Printer Model' is (stl) file type, size is 213.9KB.
Straight version of the SpeedTrap speedometer that can be placed on a straight section of N scale track and used to measure the loco's speed in MPH or KPH. There is also a 'curved' version here....
https://www.thingiverse.com/thing:6697804
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...
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....
20_Straight_Upright-7.stl | 102.6KB | |
30_St_Bottom_Main_Case-45.stl | 323.9KB | |
40_Front_Face-6.stl | 288.3KB | |
50_Top_of_Case-1.stl | 65.8KB |