GTJ Modular MarbleRun – Starter Track

GTJ Modular MarbleRun – Starter Track

This is another one of my entries for the “Marble Runs” contest on Printables.

Over the past few weeks, I have designed a growing range of GraviTrax Junior-compatible elements.
For this contest, I used several of these parts to build a complete little marble run that is fun to watch, easy to print, and simple to rebuild.

The marble starts at the top, rolls through a combination of tracks, curves, height blocks and special elements, and finally reaches the end of the run. The layout is shown step by step in the build pictures, so you can recreate the track without guessing where each part belongs.

This is not just a single track piece — it is a small modular marble run built from reusable elements.
The layout shown in the pictures is just one possible build. You can rearrange the included parts to create your own tracks, make the marble run as large as you like, and expand it with additional GTJ elements from my collection. Since the parts are designed to be compatible with GraviTrax Junior, you can also combine them with original GraviTrax Junior elements.

What is included?

All parts required to build the marble run shown in the video and pictures are included in this model. Even a 3D-printable marble is included.
Some elements are used more than once in the track. The required quantity is listed in the description of each STL file on the Files page.

All of these parts are also available as separate models on my profile.
For more detailed information, printing tips and possible variations, you’ll find links to the individual model pages at the end of this description.

I will keep expanding the GTJ system with more compatible elements, so feel free to check my GraviTrax Junior Compatible Collection for future additions.

Compatibility note

These parts are designed to be compatible with GraviTrax Junior.
They are not official Ravensburger / GraviTrax parts. They are fan-made compatible elements designed for 3D printing.

Printing information

All STL files are correctly aligned.

• 0.2 mm layer height
  

• 2 Perimeters
  

• 10% Gyroid infill works well for most parts.
  Any exceptions are described on the corresponding individual model pages linked below.
  

• Some elements need a little support in specific areas.
  The exact support requirements are shown on the individual model pages linked below.

Assembly

Use the pictures as a step-by-step guide to rebuild the marble run.

Start with the base and height blocks, then add the track elements from the bottom upwards. Once everything is assembled, place the marble at the starting point and enjoy the run.

And yes — watching the marble make its way through the track is still oddly satisfying.

Links to individual elements

More detailed descriptions for the individual parts can be found here:

File		Link	Qty
GTJ_Bodenplatte		Baseplate / Bodenplatte	5
GTJ Height Spacers Collection Note: All height spacers can be freely combined. For example, one 100 mm height spacer can be replaced by two 50 mm spacers, five 20 mm spacers, or any other combination that adds up to the same height. Larger height spacers are useful for quickly gaining height, while smaller spacers offer more flexibility when adjusting your layout.		Height Spacers / Höhensteine
GTJ_Hoehenstein_10mm			9
GTJ_Hoehenstein_30mm			4
GTJ_Hoehenstein_40mm			3
GTJ_Hoehenstein_50mm			3
GTJ_Hoehenstein_60mm			1
GTJ_Hoehenstein_100mm			2
GTJ Tunnels Collection		Tunnels (Straight & Slope)
GTJ_Hoehenstein_Tunnel			1
GTJ Drop Tower Collection		Drop Tower / Fallturm
GTJ_Spurstein_Fallloch			1
GTJ_Spurstein_Aufnahme_30mm			1
GTJ Track Stones Collection		Track Stones – Straight (Flat, Slope)
GTJ_Spurstein			5
GTJ_Spurstein_Gefaelle_10mm			1
GTJ_Spurstein_Gefaelle_20mm			1
GTJ_Spurstein_Kurve_60Grad		Track Stone – Curve 60°	5
GTJ Curve 120° Collection		Track Stones – Curve 120° (Flat, Slope)
GTJ_Spurstein_Kurve_120Grad			6
GTJ_Spurstein_Gefaelle_10mm_Kurve_120Grad_R			1
GTJ_Spurstein_Gefaelle_10mm_Kurve_120Grad_L			1
GTJ_Spurstein_Kreuzung		Track Stone – Crossing / Kreuzung	1
GTJ Bridges Collection		Bridges (Flat, Slope)
GTJ_Spurstein_Bruecke_Gefaelle_10mm_RL			1
GTJ_Spurstein_Bruecke_Gefaelle_20mm_RL			1
GTJ_Trichter		Funnel / Trichter	1
GTJ_Hammer		Speed Hammer	1
GTJ_Murmel		Printable Marble	optional

I am looking forward to your Makes! :-)

If you like this design, feel free to check out my other models here.