Preamble – just this once.
I have loved Thingiverse.com for years as a resource for 3d printer models readily available for download, and for free. While I will continue to hunt Thingiverse for models, I have made the decision to transition my model hosting to my personal website. As I try to take my modelling more seriously, I would like to start monetizing my designs by including Amazon affiliate links when projects require parts and tools. My models will still be free for download and non-commercial use and hopefully I can start building a little bit of income from my hard work.
Track Power Isolator Design
Download Links (STL and STP Model Files)
The idea for this design came around just before December 2022. Its a yearly tradition that I get my G scale train collection out and spend countless hours building a layout all stemming from a circle around the Christmas tree. This year the layout was the largest its ever been, utilizing a new 30 degree track crossing piece from LGB allowing the route to cross over itself and provide a more compact design running by the fireplace. I really wanted to get this project finished in time to use it with this year’s layout but its January 15th of 2023 and I just finished it. Better late than never and I’ll put it in the storage box ready for next year’s layout!
G scale model train track operates on DC power, one rail is ground and the other rail is positive voltage. This design allows power on one of the rails to be turned off. You run the train passed this section of track, flip the switch, and now that train no longer has power. It makes having multiple trains on the same layout easier to operate as you don’t have to remove the wheels/electrical pickups from the rails in order to stop the train from moving when power is applied to the tracks.
Parts used in this design
- M2 x 0.4 Machine Screws, 4mm Length
- Non-Insulated Ring Terminals, No. 2 Stud Size
- 1.6mm Drill & M2 x 0.4 Thread Tap
- Mini Rocker Switch
- A few inches of hookup wire, maybe 22 to 28 awg, I used solid copper 24awg, here is a recommendation
Tools used
Basic Instructions
There are more files/iterations available in the downloads section than needed to make the part pictured. To make what is pictured you’ll need;
- Qty 2 of “Sleeper – Track Clip Cavity”
- Qty 1 of “Switch Sleeper – Solid”
- Qty 1 of “Rail Clip – Isolator Triple with Mounting Holes”
- Qty 1 of “Rail Clip – Triple with Mounting Holes”
I highly recommend printing doubles of the two Rail Clip parts, they are easy to crack and break during installation and assembly. Fortunately they are small parts and fairly quick to print, you won’t be wasting too much material with a failed install or two. Try and gently press the two fingers of the Rail Clip section together where they insert into the sleepers. It takes some trial and error but you’ll get it, just go slowly.
Next, you’ll need to cut brass rail (LGB and Aristocraft rail do well) into;
- Qty 2 length 35mm sections
- Qty 1 length 75mm section
Firmly insert the rails into the sections they go into (lengths are obvious). On the undersides of the rails, mark the center points of each of the holes. You don’t need to use all of the mounting holes on the 70mm section of rail but it can’t hurt, I did. Do your best to drill the 1.6mm pilot holes for the taps into the dead center of the rail. Going too far off to one side will cause the tap to protrude from the side of the rail.
As for the electrical connections, have a look at my photo showing how I did it, its pretty self explanatory but does take careful hands and accurate eyes! I used a 1/16″ drill bit to widen the hole where the wire protrudes from the tie out to the rail hookups.