Bill of materials¶
The parts for the A2 coreXY terraPen, with sizes. The full spreadsheet, including the 3D files, is in the mechanical design files repository.
Work in progress
This list is still being checked against a finished machine. Lines marked † are not yet confirmed. Quantities marked TBC are still to be counted.
Buy links are given where there is a specific product page. Where a part says Any supplier, any source of the right size is fine.
Frame and structure¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| 2020 T-slot extrusion | 760 mm, cut, M5 tapped both ends | 4 | Frame – width | KJN Aluminium Profile, cut to size |
| 2020 T-slot extrusion | 560 mm, cut, M5 tapped both ends | 4 | Frame – length | KJN Aluminium Profile, cut to size |
| 2020 T-slot extrusion | 710 mm, cut (X rail) | 1 | Frame – X rail | KJN Aluminium Profile, cut to size |
| 2020 T-slot extrusion † | 50 mm, cut (uprights / legs), M5 tapped both ends | 4 | Frame – height | KJN Aluminium Profile, cut to size |
| 2020 corner cube connector † | 3-way, 20x20x20, black, 6 mm T-slot. Sold as 12 with screws | 8 | Frame – corners | AliExpress, 12 pcs |
| Corner cube hole caps, plastic † | 11 mm. Sold as 100, which covers several machines. The other 8 cube holes take the rubber bungs below | 12 | Frame – corners | eBay UK |
| Rubber bungs † | 11 mm. Sold as 50, which covers several machines. A slightly thicker bung would be better | 8 | Both sides of the plotter | eBay UK |
| Neodymium magnets † | Strong rare-earth magnets. Size and variant to be confirmed. Sold as 50 | 4 | Metal bed | eBay UK, 50 pcs |
| Neodymium magnets, black † | Second listing. Sold as 4 | 4 | To be confirmed | eBay UK, 4 pcs |
| 2020 corner bracket † | 90 degree, 20 x 20 x 17 mm. Sold as 10, which covers 5 machines | 2 | Frame | AliExpress, 10 pcs |
| Rubber feet † | 20 mm dia x 15 mm high, conical rubber with steel washer. Sold in lots of 4 (one machine). Bolts are not included: see the M3 x 16 button head screws below | 4 | Frame – base | AliExpress, lot of 4 |
| Metal baseboard with vinyl sticker | Ferrous Dibond-style composite, cut to shape; profile 'tP_Bed_Profile_Revised.dxf', artwork 'Diabond vinyl revised .ai' (both in /metal bed) | 1 | Base | Local sign shop, from the cut file. Countersink the holes before the vinyl is applied |
| IR cover reduction profile (5), black | Cosmetic slot cover for the 5 mm slot. KJN37080, 2 m lengths. About 5.8 m in total: 6 × 560, 2 × 760, 1 × 710 and four 50 mm pieces | 3 (buy 4 for waste) | Frame – top and side trim, front legs | KJN Aluminium Profile |
Linear motion¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| Linear rail + 1 block, MGN9H | 540 mm (Y axis) | 2 | Y left / Y right | Jugetek, custom cut to length |
| Linear rail + 1 block, MGN9H † | 710 mm (X axis) | 1 | X rail / carriage | Jugetek, custom cut to length |
| Linear rail + 1 block, MGN7H † | 50 mm (Z / pen lift) | 1 | Tool head | Jugetek, custom cut to length |
Drive: belts, pulleys and motors¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| GT2 timing belt, open † | 6 mm wide. About 4.2 m per machine | 4.2 m | X and Y belts | AliExpress, 5 m |
| GT2 pulley, toothed drive † | 20T, 5 mm bore, 6 mm belt. Sold as 10 | 2 | X motor, Y motor | AliExpress, 10 pcs |
| GT2 idler, smooth † | 20T, 5 mm bore, 6 mm belt, with bearing, no teeth. Sold as 4 | 4 | X/Y idlers, Y left/right, motor mounts | AliExpress, 4 pcs |
| GT2 idler, toothed † | 20T, 5 mm bore, 6 mm belt, with bearing. Sold as 10 | 8 | X/Y idlers, Y left/right, motor mounts | AliExpress, 10 pcs |
| NEMA 17 stepper motor, 17HS15-1504S-X1 † | 42 × 42 × 39 mm, 1.8°, 1.5 A, 45 N·cm. 5 mm D-cut shaft. 1 m lead with pin connector | 2 | X motor, Y motor | StepperOnline UK |
Electronics¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| Emerald Dingo ESP32 plotter controller (RevB) | FluidNC, 2-axis, TMC2130 driver sockets, USB-C | 1 | Electronics enclosure | terrapen.xyz |
| TMC2130 stepper driver | 3: X, Y and Z (Z via the Z-axis add-on) | 3 | Controller | terrapen.xyz driver option, or AliExpress |
| Emerald Dingo Z-axis add-on | Z motor add-on; the Z lead plugs into this | 1 | Controller | terrapen.xyz |
| Micro SD card † | 2 GB. Sold as a 5 pack | 1 | Controller | Amazon UK |
| Power supply, 12 V dc, 2.5 A | 2.1 x 5.5 mm centre-positive barrel plug, 1.5 m lead, interchangeable mains plugs (Ideal Power 15DYS830-120250W-K) | 1 | Power | Farnell UK |
| Motor cable, 4-way | 4-core PVC cable, 26 AWG, flexible, unshielded, 920 mm, JST PH 2.0 | 1 | X motor | Any supplier |
| Motor cable, 4-way | 4-core PVC cable, 26 AWG, flexible, unshielded, 515 mm, JST PH 2.0 | 1 | Y motor | Any supplier |
| Hook-up wire, Alpha Wire 3049 BK001 | 26 AWG PVC black, 7 x 34 tinned stranded, 300 V, 1000 ft reel (order code 01-5540) | 1 | Z motor lead and X endstop lead (single cores) | Rapid Electronics |
| Multicore cable, 4-core PVC † | 26 AWG, flexible PVC, unshielded: X lead 920 mm + Y lead 515 mm (1.435 m), plus spare | TBC | X and Y motors | Any supplier |
| Multicore cable, 3-core PVC † | 3-core PVC, 26 AWG ; Y endstop lead only, 920 mm, plus spare | TBC | Y endstop | Any supplier |
| Insulation tape for colour-coding | Red, green, yellow and blue, cut into 1 mm strips. One roll of each is enough for many machines | 4 rolls | Z lead and single-core leads | Any shop, or eBay |
| JST SM 2.54 mm connector kit † | Male and female housings (SM-02 to SM-05) and bare terminals. You use one 4-way female, one 4-way male and two 3-way females per machine, so one kit covers about 2 machines. Check the housings fit your endstop modules | 1 kit | Z motor lead, X and Y endstop leads | eBay UK |
| Optical endstop | 3-pin module (SIG / GND / VCC) | 2 | X and Y limits | Ooznest (SKU ESTOP-O) |
| Standoff, male-female, polyamide | M3 × 18 mm, hex 6 mm (Wurth 971180365). A cheap 20 mm nylon set also works if you trim it to 18 mm with a knife | 2 | Electronics enclosure | Mouser UK |
| Standoff, male-female, nylon † | M3 × 16 mm (Essentra 36M30MF016). Only if you fit the Z-axis add-on (the Z board is thick and stacks on the controller) | 1 | Electronics enclosure | Mouser UK |
| DC barrel jack: plug and socket pair † | 2.1 x 5.5 mm, centre-positive, to match the supply | 1 | Power connection | eBay UK, 10 pairs |
| Power wire, 2-core 18 AWG, 16 A rated † | About 750 mm per machine | 1 | Power wiring | eBay UK, 10 m |
| Power switch, rocker † | Check the cut-out size against the printed switch mount | 1 | Power switch mount | eBay UK, 5 pcs |
| JST PH 2.0 connector kit | Housings (2 to 6-way) and crimp terminals. You use three 4-way, two 3-way and two 6-way housings and 26 terminals per machine, so one kit covers about 5 machines | 1 kit | Controller and motor ends of the motor and endstop leads | eBay UK |
| Waveshare round display (optional, for terraDial) † | Exact model to be confirmed | 0 or 1 | Optional dial controller | AliExpress |
Cable management and miscellaneous¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| Cable chain † | 7 x 7 mm inner, black nylon, 1 m lengths with end connectors. About 1.4 m needed, so buy 2 x 1 m | 1.4 m | Y right and carriage | AliExpress |
| D-Line Micro+ trunking, black † | 20 × 10 mm, 2 m length, self-adhesive. About 1.6 m needed (runs of roughly 2 × 250, 200, 600 and 300 mm) | 1 | Underside cable routing | Screwfix |
| Trunking 90-degree flat corner † | Print your own (STL), or the D-Line accessories pack | 2 | Underside cable routing | Screwfix |
| Cable ties † | Black, 2.5 mm wide. Sold as 100 | 6 | General | eBay UK, 100 pcs |
| Hex key set | 1.5 / 2 / 2.5 / 3 / 4 mm | 1 | Assembly (tool) | Any supplier |
Fasteners: M2¶
Buy only what you need
Allfix sells screws and nuts singly as well as in packs, so you can order exactly the quantities in these tables.
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| Socket head screw † | M2 x 8, self colour, hex socket | 7 | Stepper tool head: MGN7H rail (3), pen holder (4) | Allfix |
| Heat-set insert † | M2 × 3 mm brass | 3 | Stepper tool head plate (MGN7H rail) | eBay UK, pack of 100 |
Fasteners: M3¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| Countersunk screw † | M3 x 5, self colour, hex socket | 6 | Y gantry end (2), carriage energy chain (2), belt clamps (2) | Allfix |
| Countersunk screw | M3 x 6, self colour, hex socket | 17 | Electronics cover (3), gantry ends (6), tool head carriage (4), belt clamp (2), tensioner (2) | Allfix |
| Countersunk screw | M3 x 8, self colour, hex socket | 15 | Y motor (2), Y homing arm (2), gantry clamps (2), energy chain mount (1), NEMA 14 (4), tool head plate (4) | Allfix |
| Countersunk screw † | M3 x 16, self colour, hex socket | 5 | X motor mount (2), pen clip assembly (3) | Allfix |
| Countersunk screw | M3 x 30, self colour, hex socket | 4 | X and Y motor mounts (2 each) | Allfix |
| Button head screw | M3 x 6, self colour, hex socket | 6 | Controller board (2), Y endstop (2), X endstop (2) | Allfix |
| Button head screw † | M3 x 8, self colour, hex socket. Z-axis add-on only: replaces one of the controller's M3 x 6 screws | 1 | Controller board (with Z add-on) | Allfix |
| Button head screw | M3 x 16 (approx.), self colour, hex socket. The feet come without bolts; check the length when they arrive | 4 | Frame – feet | Allfix |
| Socket head screw | M3 x 8, self colour, hex socket | 14 | Y rails (8), gantry rail (4), pen-lift spring (2) | Allfix |
| Nyloc nut | M3, A2-304 stainless steel, DIN 985 type T | 2 | Z tool head: pen-lift spring (1); rear of the pen holder, in the slot (1) | Allfix |
| T-slot nut with spring ball, M3 † | KJN43719, 5 mm slot, 8 × 4.2 mm, zinc-plated steel | 17 | Feet (4), Y rails (8), gantry rail (4), energy chain mount (1) | KJN Aluminium Profile |
| Heat-set insert | M3 x 3 mm brass | 1 | Belt clamp, rear of the tool head | The Pi Hut |
Fasteners: M5¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| Countersunk screw | M5 x 8, self colour, hex socket | 33 | Metal bed (8), X/Y motors (6), idler ends (8), gantry top plates (4), chain supports (4), power switch (2), Y endstop mount (1) | Allfix |
| Countersunk screw | M5 x 20, self colour, hex socket | 6 | Gantry ends (4), idler axles (2) | Allfix |
| Button head screw | M5 x 12, self colour, hex socket | 22 | Frame – corner cubes | Allfix |
| Button head screw | M5 x 8, self colour, hex socket | 6 | L brackets (4), electronics mount (2) | Allfix |
| T-slot nut with spring ball, M5 † | KJN37001, 5 mm slot, 8 × 4.2 mm, zinc-plated steel | 43 | See the M5 screws above (one nut for each screw that goes into the extrusion) | KJN Aluminium Profile |
Z stepper pen-lift head¶
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| NEMA 14 stepper motor, 14HS17-0504S | 35 × 35 × 42 mm, 1.8°, 0.5 A, 23 N·cm. 5 mm D-cut shaft. 4-wire lead, 300 mm | 1 | Pen lift | StepperOnline UK |
| GT2 timing belt, 6 mm (pen lift) | About 40 mm, cut from the spare belt left on the 5 m reel above | 0.04 m | Pen lift | AliExpress, same reel |
| Z motor lead (through the energy chain) | 4 x single-core Alpha Wire 3049 BK001, 26 AWG tinned copper PVC, black; 2100 mm each | 1 | Z motor | Made from the hook-up wire |
| Extension spring † | 5.2 mm diameter × 20.6 mm long | 1 | Stepper tool head (front of the plate, bottom left) | eBay UK, 10 pcs |
| Stepper head fasteners † | To be listed | TBC | Plotter head | Any supplier |
| Thumb screw, M3 x 12 † | Steel, knurled head. Sold as 10 | 1 | Pen setter gauge | AliExpress, 10 pcs |
Printed parts¶
The printed parts cost about £85 per machine in filament and printing.
| Part | Size / spec | Qty | Used in | Where to buy |
|---|---|---|---|---|
| X idler top (XIT) | X_Idler_Top.stl | 1 | X idler | Print: STL |
| X idler bottom (XIB) | X_Idler_Bottom.stl | 1 | X idler | Print: STL |
| Y idler top (YIT) | Y_Idler_Top.stl | 1 | Y idler | Print: STL |
| Y idler bottom (YIB) | Y_Idler_Bottom.stl | 1 | Y idler | Print: STL |
| X motor top (XMT) | X_Motor_Top.stl | 1 | X motor | Print: STL |
| X motor bottom (XMB) | X_Motor_Bottom.stl | 1 | X motor | Print: STL |
| Y motor top (YMT) | Y_Motor_Top.stl | 1 | Y motor | Print: STL |
| Y motor bottom (YMB) | Y_Motor_Bottom.stl | 1 | Y motor | Print: STL |
| X axis bracket top, left (XYT) † | Xy_Carriage_Top.stl | 1 | Y left | Print: STL |
| X axis bracket bottom, left (XYB) † | Xy_Carriage_Bottom.stl | 1 | Y left | Print: STL |
| X axis bracket top, right (YXT) † | Xx_Carriage_Top.stl | 1 | Y right | Print: STL |
| X axis bracket bottom, right (YXB) † | Xx_Carraiage_Bottom.stl | 1 | Y right | Print: STL |
| Energy chain bracket (ECB) † | No STL found | 1 | Y right | Print (no STL yet) |
| Carriage (RUM) † | Tool_Carriage.stl | 1 | Carriage | Print: STL |
| Belt clamp front (BCF) † | Belt_Clamp_Plate.stl | 1 | Carriage | Print: STL |
| Belt clamp back (BCB) † | Belt_Clamp_Teeth.stl | 1 | Carriage | Print: STL |
| Tensioner housing (T) † | Tensioner_Housing.stl | 1 | Carriage | Print: STL |
| Tensioner bit † | 2xTensioner_bit.stl | 2 | Carriage | Print: STL |
| Lower energy chain bracket † | No STL found | 1 | Carriage | Print (no STL yet) |
| Minimal pen holder (MPH) † | Pen_Holder_Front.stl | 1 | Tool head | Print: STL |
| Pen clip block † | Pen_Clip_Block.stl | 1 | Tool head | Print: STL |
| Pen clip latch † | Pen_Clip_Latch.stl | 1 | Tool head | Print: STL |
| Pen clip link † | Pen_Clip_Link.stl | 1 | Tool head | Print: STL |
| Electronics enclosure (EE) | Electronics Enclosure.stl | 1 | Electronics | Print: STL |
| Electronics enclosure top plate (EETP) † | No STL found | 1 | Electronics | Print (no STL yet) |
| Power enclosure box | Power_Enclosure_Box.stl | 1 | Power | Print: STL |
| Power enclosure back | Power_Enclosure_Back.stl | 1 | Power | Print: STL |
| X endstop top | Xx_Endstop_Top .stl | 1 | X endstop | Print: STL |
| X endstop bottom | Xx_Endstop_Bottom.stl | 1 | X endstop | Print: STL |
| Y endstop mount | Y_Endstop_Mount.stl | 1 | Y endstop | Print: STL |
| TPU bumper | 8xTPU_Bumper.stl | 8 | Frame / base | Print: STL |
| Cable cap for extrusion | Cable Cap for Extrusion.stl | 1 | Frame | Print: STL |
| Clip mount | skinnyClipMount.stl | 1 | Unknown | Print: STL |
| Stepper tool carriage | stepper_tool_carriage.stl | 1 | Tool head (stepper) | Print: STL |
| Stepper pen mount | stepper_pen_mount.stl | 1 | Tool head (stepper) | Print: STL |
| Stepper pen mount clamp | stepper_pen_mount_clamp.stl | 1 | Tool head (stepper) | Print: STL |
| Stepper belt pulley | stepper belt pulley.stl | 1 | Tool head (stepper) | Print: STL |
| NEMA 14 mount to carriage | Nema14mount2carriage.stl | 1 | Tool head (stepper) | Print: STL |
| TPU pen bung – 10mm Tapered | TPU Bungs/10mm Tapered Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 11mm Tapered | TPU Bungs/11mm Tapered Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 12mm Aperture | TPU Bungs/12mm Aperture Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 15mm Aperture | TPU Bungs/15mm Aperture Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 16_3mm Tapered | TPU Bungs/16_3mm Tapered Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 4mm Aperture | TPU Bungs/4mm Aperture Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 6mm Aperture | TPU Bungs/6mm Aperture Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 8mm Tapered | TPU Bungs/8mm Tapered Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 9mm Aperture | TPU Bungs/9mm Aperture Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen bung – 9mm Tapered | TPU Bungs/9mm Tapered Bung.stl | 1 | Pen holder insert | Print: STL |
| TPU pen holder insert (parametric) † | Stepper_Z_Axis_Experimental/Pen Holder Insert.FCStd | 1 | Pen holder insert | Print: STL |
| D-Line 20 × 10 flat corner (trunking) | D_Line_20x10_Flat_corner.stl. 0.4 mm nozzle, black PLA, brim of 3 or 4 lines | 2 | Underside cable trunking | Print: STL |
| Chain support (energy chain anti-sag clip) | CHAIN_SUPPORT.stl | 4 | Gantry underside; also terapixel light clips (work in progress) | Print: STL |
Tooling¶
You only buy these once, so they are not part of the per-machine parts list.
| Tool | Notes | Where to buy |
|---|---|---|
| Hex keys | 1.5, 2, 2.5, 3 and 4 mm | Any supplier |
| Soldering iron that takes Hakko-type tips | Used to fit the heat-set inserts, and for wiring | Any supplier |
| Heat-set insert tip | Virtjoule tip for #4-40 / M3 inserts. It fits M3 only: the three M2 inserts on the pen-lift plate need a smaller tip † | The Pi Hut |
| M3 and M5 taps † | The M5 tap is only needed if your extrusion supplier does not tap the ends for you | RS (Wera M5 tap) |
| Crimping tool † | For JST PH and JST SM connectors. IWISS SN-2549 ratcheting crimper (0.08 to 1.0 mm²) | Amazon UK |
See cables and wiring for how the leads are made.