Roll Hexfinity Fractal Ball Runs

Roll Hexfinity Fractals - a Modular, Fractal, Infinite Ball System

Fractals are mesmerizing. Getting to build them, play with them hands-on and watch balls flow through recursive geometry in real life… it's a whole other level. Roll Hexfinity Fractals turns beautiful math into a modular roll maze system with beautiful, deep geometry.

I was inspired by two things when I designed this set: 

1. Roll Time: Roll Hexfinity has always been fast — the balls fly through the system. The fun is often over way too fast.
2. Fractals: I've always been fascinated by geometry, math and … fractals! Much of Hexfinity exists because of my joy of exploring its geometry. 

And… I've been looking for inspiration to make a bigger Roll Hexfinity set. This is the biggest set I’ve ever released. Roll Hexfinity Fractals Level 3:

• 131 total pieces (including plates, bases, and pillars)
• 49 roll-path bricks (Level 3)
• 6 new Fractal brick types (60° left/right, 120° left/right, plus S and Z straights)
• Level 3 build height is approximately 346mm
• Total Ball Path Length: 5,748mm (over 5 meters!)
• Total roll time: > 50seconds (~1 second per brick)

What’s New in This Set

6 New Fractal Path Bricks

• 60° Left - 7mm rise, 118mm run (path-length - 6% grade)
• 60° Right - 7mm rise, 118mm run (path-length - 6% grade)
• 120° Left - 7mm rise, 117mm run (path-length - 6% grade)
• 120° Right - 7mm rise, 117mm run (path-length - 6% grade)
• Straight “S” - 7mm rise, 100mm run (path-length - 7% grade)
• Straight “Z” - 7mm rise, 100mm run (path-length - 7% grade)

Original Roll Hexfinity Bricks had a 7mm rise but only a 42, 38 or 25mm run for the straight, 60deg and 120deg paths respectively (17%, 18%, and 28% grade!). That means these new bricks provide 2.5 to 4.5x longer ball paths per piece!

New 8-Hex Base and Plate (0HU & 1HU)

In order to make the set stable at such a height, I designed a new configuration of bases and plates:

• 8hex 0mm/0HU Base - Allows for 7 roll brick plus the sink brick
• 8hex 7mm/1HU Plate - Allows for 7 roll pricks plus one extra to interlock with the next plate

New Pillars

At Level 3, the system climbs fast:

• each brick drops 7mm
• 49 bricks
• 49 * 7mm = 336mm = ⅓ meter path height!

So this release also includes upgraded support infrastructure:

• New 24HU Pillars
• New Ultralight Pillars
• All Pillars: print-speed and quality improvement

The new pillars are available individually here: Hexfinity Pillars v1.1 - Max Height, Min Weight

Print Profiles

I included several print profile options for you. They are grouped as follows:

• A1Mini vs A1/P1/X1 etc 
• Level 1 set, Level 2 set, level 3 set
  • Level 2 and Level 3 sets are split into “a” and “b” parts. This is so you can easily print the roll bricks in a different color.
• Pieces - one profile has each new piece, one per plate, for easy printing
• Level 3 Instructions - one profile has the exact 7-brick layout for each plate of the Level 3 set. This is a great reference if you get lost assembling. It's also a great option if you have lots of printers and want to parallelize your prints.

Three Sets, Three Levels

This release is split into three different sets you can print - the first three recursion levels, so you can choose how deep you want to go:

• Level 1: 1 fractal brick 
• Level 2: 7 fractal bricks (a full “macro tile”)
• Level 3: 49 fractal bricks (a full recursive layout)

All three levels in this release focus on the Z-path recursion, because it’s the clearest way to see the fractal behavior emerge.

Fractal Roll Hexfinity Set Level 1 (5 pieces)

Level 1's “Z” path is just a single brick! A fast, easy print to see the basic pattern.

Pieces

• 1x Fractal “Z” Brick
• 1x Source Brick
• 1x Sink Brick
• 1x 3-Hex Base (0mm)
• 1x 1-Hex Plate (7mm)

Fractal Roll Hexfinity Set Level 2 (18 pieces)

Level 2's “Z” path takes 7 bricks:

• 1x Fractal 120deg Left Brick
• 1x Fractal 120deg Right Brick
• 2x Fractal 60deg Left Bricks
• 2x Fractal 60deg Right Bricks
• 1x Fractal “Z” Brick

In addition, you'll need the following support structure. I split these into a separate print profile so they can print faster. The Fractal bricks need 0.125mm layer height, but the support bricks work great at 0.25mm.

• 1x 8-hex Base (0mm)
• 1x 2-hex Plate (7mm)
• 1x 1-hex Plate (7mm)
• 1x 2HU Pillar (14mm)
• 1x 3HU Pillar (14mm)
• 1x 4HU Pillar (14mm)
• 2x 5HU Pillar (14mm)
• 1x 6HU Pillar (14mm)
• 1x Source Brick
• 1x Sink Brick

Fractal Roll Hexfinity Set Level 3 (131 pieces)

Note: See the full instructions PDF for assembly of the Level 3 set.

Level 3's “Z” Path is the full experience! 7*7 = 49 fractal bricks:

• 8x Fractal 120deg Left Brick
• 8x Fractal 120deg Right Brick
• 16x Fractal 60deg Left Bricks
• 16x Fractal 60deg Right Bricks
• 1x Fractal “Z” Brick

The 2nd print profile (3b) is for all your structures - optimize for print speed. Note, you will need to print multiple copies of some plates as indicated in their plate names (e.g. “2 copies”). All Level 3b pieces:

• 7x 8-Hex Plates (7mm)
• 1x 8-Hex Base (0mm)
• 11x 1-hex Plate (7mm)
• 9x 2HU Pillars
• 9x 3HU Pillars
• 9x 4HU Pillars
• 16x 5HU Pillars
• 8x 6HU Pillars
• 4x 12HU Pillars
• 2x 18HU Pillars
• 6x 24HU Pillars

Fractal Roll Hexfinity Set Level 4 (Not Included!) 

Imagine Level 4! Take 7 of the Level 3 sets plus more plates and pillars: 7 × 49 = 343 fractal bricks! Imagine 343 * 7mm = 2,401mm of vertical ball drop and over 5 minutes of roll time! If you build it, I want to see it! 

If you seriously want to build this, but want some help with improved pillars for such an undertaking, let me know. I've got some ideas.

Fractal Challenges

Part of what I love about Hexfinity is the geometry. With this set, I loved discovering the fractal & geometry math that fell out from the constraints. Below are a set of challenges I came up with for those who want to explore the system further. Some of the answers will surprise you!

Challenge 1: Basic scaling up

Pick any Level 1 Fractal roll brick. Then build a Level 2 layout (7 hexes) that matches the same “macro behavior”:

• “S” Straight-through (the included set is the “Z” straight through)
• 60° turn (left or right)
• 120° turn (left or right)

Challenge 2: The mirror challenge

Build a Level 2 layout (7 hexes) using one macro path… then build its mirror image. Tip: You can’t complete the mirror using rearrangement alone — you’ll need to replace some bricks. 

• Question: What’s the minimum number of bricks you need to swap to create the mirrored version?
• Advanced: Do the same challenge at Level 3 (49 hexes).

Challenge 3: Advanced scaling up (Level 3)

Pick one Level 1 Fractal brick as your “seed”. Build a full Level 3 layout (49 hexes) so the entire big layout follows the same overall macro path as your original seed brick.
 

Challenge 4: Build the Gosper path

Build a Level-2 (7-hexfinity-brick) Gosper path.

• Question: How does the configuration of bricks change compared to those found in the Roll Hexfinity Fractals Level 2 profile?

Challenge 5: Mathematical challenges

5a. The “minimum kit” puzzle

• Level 2: What’s the minimum number of bricks you need, by type, in your “bag of parts” to build any of the six macro paths at Level 2?
• Level 3: Same question, but for Level 3.
• Master: What’s the general equation for the minimum number of bricks needed at any level?

5b. The S/Z mystery

S and Z bricks behave differently than turn bricks in the recursion.

1. Question: At a given fractal-level, what’s the maximum number of S/Z bricks you’ll ever need?
2. Question: Where are S/Z bricks allowed to appear?

5c. The exact brick mix

Now that you know the counts, solve the brick composition:

1. Question (by level): For a given level, what’s the exact count of each Fractal brick type?
2. Question (by path): How does that mix change depending on which macro path you’re building?

5d. “Roll Hexfinity Fractals Level 4”

Level 3 isn't the end. You could consider Level 4, Level 5 and beyond! 

• Question: How many path bricks do you need for Level 4? Level 5? Level X?
• Question: How tall would Level 4 be? (5? X?)
• Question: Each platform has two support pillars. For level 4, what's the fewest number of Roll Hexfinity Pillars needed for the tallest platform on Level 4?
• Question: How may KG of filament would you need for Level 4? (5? X?)

Inspiration

I was inspired to build this set when I saw Gosper Curve Fractal Marble run (8mm) by giraffe112358. It's a great design, but… I really wanted a modular version. I'm never satisfied with a single, fixed ball path. 

Summary

• 6 new Fractal bricks (60°/120° turns + S/Z straights)
• Internal zigzag paths maximize roll time inside one hex
• 3 recursion levels included (1 / 7 / 49)
• Level 3 kit = 131 total pieces
• Tall, stable builds supported by improved pillars
• Includes challenge puzzles for fractal + math exploration

This one is pure modular math joy.

Print it. Build it. Watch it roll.

Then try to solve it.