Build a pen plotter

Build a two-axis machine that draws with a real pen: two stepper motors move the paper and the pen, a small servo lifts the pen, and free GRBL firmware turns drawings into moves.

Time4–6 weekends

Parts₹4,240–4,368

Frame and axes built8 actions · read it below
Drivers set, motors turning4 wires, 12 actions
Axes moving to size6 actions
Pen lifts, first square3 wires, 7 actions
GRBL running, plotting from G-code7 actions
Tuned, and a real drawing6 actions

Start this build

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Before you start

Tools: Laptop with the Arduino IDE, Multimeter (you need it to set the motor current), Small screwdriver, ideally plastic or ceramic, for the driver trimmers, Drill, screwdriver, saw, steel rule and set square, Hardware-shop bits: 12 mm plywood or MDF for the base, thinner ply for the bed, bridge and carriage, wood screws, M3–M5 bolts and nuts, cable ties, a small hinge, Felt-tip or gel pens and paper, Optional: a 3D printer, if you'd rather print brackets than cut wood
Skills: Harder: a good second or third build. Woodwork and careful measuring; steps 2–4 use code (or Get the code); steps 5–6 use free software (GRBL and a G-code sender).
Safety: 12 V from a plug-in adapter: never open the adapter. Never plug or unplug a stepper motor while the power is on: it can destroy its driver. Driver heatsinks get hot, and belts and pulleys can pinch fingers.
Prices: Checked 2026-10, Robocraze prices with a clone Uno and green A4988 drivers; the top figure has red A4988s and two 1 m motor cables, in case your motors come without them. Plywood, screws, bolts, cable ties, a small hinge and pens come from a hardware shop and aren't included. An original Uno adds about ₹1,950.

Step 1 of 6

Frame and axes built

The base, the moving bed (Y) and the bridge with its carriage (X) are built, with motors, pulleys and belts fitted, and both axes slide smoothly by hand along their full length.

Build it

Task 01 of 08

Read the plan first. The bed carries the paper and slides front to back on two rods fixed to the base: that is Y. A bridge stands over the bed with two more rods running left to right; the carriage slides on them and carries the pen: that is X. Each axis has one motor and one belt.

Check: Draw your layout on paper with sizes before you cut anything.

Steps

You need

4 × 8 mm smooth steel rods, 400 mm (Robocraze lists them as 'M8 400mm Stainless Steel Rod': they are smooth, not threaded)
8 × SK8 rod supports
8 × LM8UU linear bearings
2 × NEMA17 stepper motors (17HS4401: 1.8°, 1.7 A) and 2 × NEMA17 L-brackets
2 × GT2 20-tooth pulleys (5 mm bore) and 2 × GT2 20-tooth idlers (5 mm bore) with M5 bolts and nuts
2 × 1 m of 6 mm GT2 belt
Base: 12 mm plywood or MDF, about 50 × 45 cm; thinner ply for the bed (about 25 × 25 cm), two bridge uprights and the carriage (about 8 × 8 cm)
Wood screws, cable ties, M3–M5 bolts and washers

Build a pen plotter

Parts list

Frame and axes built

Build it