🌀 Spirograph Drawing Machine: step-by-step build

A machine that draws flowers! The paper spins while an arm swings the pen.

Can a machine be an artist? This one can! Tape a piece of paper on the spinning table and clip a felt pen into the swinging arm. One crank does everything: corner gears turn the table slowly, and another pair of corner gears turns a little crank that rocks the pen arm in and out. Because the table and the arm go at different speeds, the pen draws loops that grow into a flower. Change one gear and you get a whole new pattern! (You need a felt pen, paper and some sticky tape.)

Level 3 of 5 (medium)
About 45 minutes
19 steps, 48 parts
Powered by: Hand-crank
Series: Mechanical Wonders

What you will learn

Gear Ratio: Fast or Slow: A big gear turning a small gear makes it spin faster.
Linkages: Beams joined by pins change one motion into another.
Turntables: A turntable lets a whole model spin round.
Bevel Gears: Around the Corner: Slanted gears send spinning power around a corner.

Build these first

📡 Spinning Radar: A motor-driven radar dish that sweeps round and round on a turntable — with a blinking light. (level 3 of 5, about 25 minutes, 15 steps)
🌬️ Bevel-Gear Windmill: Turn the handwheel at the bottom — the sails spin at the top! (level 3 of 5, about 25 minutes, 16 steps)

Parts you need

1 × Open frame 5×11
1 × Turntable
4 × Blue long pin
4 × Split pin block
3 × Axle 3
2 × Cross block
3 × Axle 7
3 × Corner gear (12 teeth)
6 × Half bush
2 × Bush
1 × Hand crank
1 × Beam 7
2 × Red axle-pin
1 × Double cross block
2 × Black pin (grippy)
1 × Open frame 5×7
1 × Axle 5
1 × Beam 5
1 × Axle 4
1 × Thin beam 3
1 × Beam 11
1 × Axle-hole connector
1 × L-beam 2×4
3 × Grey pin (smooth)
1 × Beam 3

Steps

Lay the white 5×11 frame flat, pointing away from you.
Put the turntable on the near end of the frame.
Bearing stands: push blue long pins up into the 5th and 7th holes of the left long side, and slide two split pin blocks down onto them, one on top of the other.
Do the same further along: blue long pins in the 9th and 11th holes, and two more split pin blocks.
Push a 3-long axle into the near top block, pointing in, and slide a cross block onto it, with its round side hole underneath. This is the first bearing for the crank shaft.
Hold a corner gear touching the turntable's teeth, a half bush and a second corner gear in a row, and push the long axle from the far end through the gears, the bush and the bearing.
Slide a bush onto the far end of the axle, into the space between the second corner gear and the far stand. Slip a cross block onto the axle at the far stand, round hole first, and lock it with a 3-long axle pushed in through the top block. Put the red hand crank on the end.
Paper table: lay a 7-hole beam flat and push a 3-long axle through its middle hole so it sticks out underneath. Push a red axle-pin into the beam two holes along and slide a double cross block down onto the axle and the axle-pin.
Push black pins into the beam's end holes and press the 5×7 frame flat onto them, around the block.
Plug the paper table's axle straight down into the middle of the turntable.
Push a 5-long axle down into the left side of the frame and a 7-long axle into the right side, halfway along. Slide a half bush down each axle, stopping just under where the beam goes: it locks the axle between the frame and the beam.
Slide a 5-hole beam flat onto both axles.
Hold a corner gear and a half bush under the middle hole and push a 4 axle down through the hole, the bush and the gear, until the gear sits on the other corner gear. Slide a half bush down onto the top: it holds the beam down.
Put the thin 3-hole crank on top.
Pen arm: take an 11-hole beam.
Push a red axle-pin up into hole 10, pin end first, and push the pen holder's cross hole onto its axle end. Push a felt pen through it so the tip just touches the paper.
Push another 7-long axle down into the far right corner. Slide a bush down the right axle onto the beam and a half bush down the new axle to the same height, then slide the black L-beam flat onto both tall axles, resting on them, its short leg sticking out to the side.
Lay the arm on the end of the L-beam and push a grey pin through both: this is the arm's hinge.
Join the crank to the arm with a 3-hole link and two grey pins.

Play time

Tape paper on the table, clip in a felt pen and crank slowly. Count the petals! Now move the link to a different hole of the arm — does the flower get bigger or smaller?

Real-world inspiration

Spirograph and harmonograph drawing machines — https://en.wikipedia.org/wiki/Spirograph ; Brick Experiment Channel mechanisms — https://brickexperimentchannel.wordpress.com/2022/11/14/20-mechanical-principles-machine/