Took the amazing design from Ed and added some variations. I just got a SCX24 and the original track width with the stock SCX24 is super close. I was hoping to figure out a solution so people wouldn't have to reprint track pieces if they wanted to change to a narrower track width. The best I could do was only having to reprint half of the track pieces, e.g. keep one original cube track piece and print one cubes 3 wide or cubes 2 wide track piece and then connect them to get a SCX24 track width.

Differences of the remix compared to the original

track 3 wide - removed one hole width from one side of track piece. use for narrower track widths like a stock SCX24 where you want only three holes between tracks.

track 2 wide - removed one hole width from both sides of track piece. use for narrower track widths like a stock SCX24 where you want only three holes between tracks.

connector 3 - a three length connector with three connection points

connector + 1 space - a three length connector with a blank in the middle. use to make track width wider. can be used to make original track pieces wider for custom trx4m builds.