Archimedes Screw Marble Machine - hand crank, jump & click track (multicolour, no supports)

The GIF shows the real motion, computed frame by frame from the same simulation the checks use: turn the crank and an Archimedes screw lifts the marbles up a see-through lattice tower; at the top they roll out, zigzag down a track, jump through a window, rattle over a click ramp and come back to the screw, forever.

How it works

• The crank turns a pair of 1:1 bevel gears on top of the tower, which turn the screw. Each crank turn lifts every marble 28 mm; 6 marbles can go round at the same time (one leaves the top on every turn).

• A fixed rail inside the tower stops the marbles from spinning with the screw, so the screw pushes them up. The flight is tilted 10° towards the core, so the marble rides against the core; near the top the tilt changes to 14° outwards and the marble rolls out by itself onto the exit sill.

• At the bottom, a 0.5 mm knife edge on the start of the flight scoops the waiting marble off the floor.

• The track is a groove cut into a panel: front lips leave a 12 mm slot, so you see the marble but it cannot fall out (not even a 12.7 mm steel ball).

• The jump: a 16° accelerator and a small kicker launch the marble at about 0.38 m/s; it flies over a 17 mm drop through a window and lands on the catch ramp. Then 10 tiny ridges (0.4 mm) make it go "click-click-click", and three C-turns bring it to the tower.

Details

• Size: base 174 × 63 mm, 211 mm tall to the top of the crank knob. Every part fits the A1 mini bed (175 × 175).

• Marbles: designed for 16 mm glass marbles; 14 mm marbles and 1/2" (12.7 mm) steel balls also work (the rail stops them a little earlier and the exit walls guide them).

• Track: 4-row zigzag, all slopes 4° or steeper (5° rows, 16° accelerator, C-turns), 0.6 mm clearance all round the marble, steps only downwards and at most 0.3 mm where two parts meet.

• Tower: open lattice (52° braces, no supports), screw Ø32 mm with a 28 mm pitch, bevel gears module 1.75 with 14 teeth, D-shafts (Ø8).

• Colour details: white face with coral and yellow stripes along the slots, a yellow frame around the jump window, "JUMP!", "click click click", direction arrows, a small HANMA, and "ARCHIMEDES MARBLE LIFT" on the base.

Printing

• Bambu Studio, A1 mini (+ AMS lite for the first two plates), 0.2 mm layers, 15% infill, no supports. Total 8 h 26 min, 219 g:

• Plate 1, track panel, printed face up: 2 h 34 min, 108 g. AMS: 1 navy, 2 white, 3 coral, 4 yellow. Only one colour change from navy to white, then 3 colours in the last 3 layers.

• Plate 2, base: 0 h 58 min, 36 g (navy + white inlays in the top 3 layers).

• Plate 3, lattice tower (white): 2 h 28 min, 35 g.

• Plate 4, screw (yellow), printed standing: 1 h 29 min, 20 g.

• Plate 5, head + 2 gears + crank + shaft (coral): 0 h 55 min, 20 g. The only bridges are a straight 43 mm one over the screw and the 17 mm lintel of the exit window.

Assembly

1. Push the panel into the base slots and the tower into its round socket (0.2 mm fits).

2. Drop the screw onto the pin in the tower floor, put the head on the three pegs, slide the screw gear onto the D-shaft until it sits on its washer (a drop of glue keeps it).

3. Push the crank shaft through the bearing, fit the crank gear on the inner end and the crank on the outer end (glue optional). Add the marbles and turn the crank clockwise when seen from the right.

How it was checked

• Marble path: the centre of the ball was followed through the whole cycle (901 positions: lift, roll-out, track, jump, entry, wait and pick-up) against the real meshes: it never cuts into a part and always rests on something except in the air. It stays at least 0.5 mm from walls, lips and ceilings, and 0.60 mm from the next flight and the tower. A ball 2 mm bigger (18 mm) does not fit the channel: it would jam.

• Slopes: every rolling section is 4° or steeper (the only flat spot is the 4 mm place under the screw where the knife edge picks the marble up). Steps measured with rays on the meshes: 0.31 mm and 0.27 mm downwards at the two joints, nothing else.

• Jump: ballistic flight with the speed the marble gains (rolling ball, 5/7 g): it lands 5.7 to 15.0 mm past the catch edge for any loss from 0 to 30%. Control: with the jump 20 mm longer it hits the edge and falls out.

• Mechanism, 36 positions of the crank: the gears never collide (about 0.32 mm backlash; half a tooth off they do collide), the screw grown by 0.25 mm on every face touches nothing (grown by 1 mm it rubs the rail, which is 0.8 mm away), and gears, shaft and crank keep at least 0.25 mm from everything.

• The 6 marbles together in the 36 frames of the GIF: no overlaps with parts or with each other. Colours: no overlaps, they fill each part exactly. All fits 0.2 mm (0.3 mm off already collides). No overhangs over 45°, nothing floating.

About this design

Designed with AI assistance and checked in code before release (see above). Pictures are 3D renders and the slicer preview, not photos. Not printed yet: makes and feedback are very welcome.

Español

Máquina de canicas de manivela: unos engranajes cónicos giran un tornillo de Arquímedes que sube las canicas por una torre de celosía; arriba salen solas, bajan en zigzag, saltan por una ventana, hacen clic-clic-clic y vuelven al tornillo. 6 canicas a la vez, todo comprobado en código, 5 placas sin soportes en el A1 mini (8 h 26 min, 219 g).

العربية

آلة كرات زجاجية تعمل بالذراع: تدير تروس مخروطية لولب أرخميدس فيرفع الكرات داخل برج شبكي، ثم تنزل في مسار متعرج وتقفز عبر نافذة وتطقطق على منحدر صغير ثم تعود إلى اللولب بلا توقف. 6 كرات في وقت واحد، خمس لوحات طباعة بلا دعامات على A1 mini.