PAROL6 parts list
3D printed six axis desktop arm with industrial style belts, planetary gearboxes and open Python control software.
Robot armsadvanced by Source Robotics (Petar Crnjak)
Total parts cost: $750 to $1,150 (cheapest listed sellers add up to about $119)
DIY sourcing per BOM.md: official control board, 6 steppers, 3 EG gearboxes, bearings, belts, sensors, pneumatic gripper, screws, about 3 kg filament. Excludes 3D printer, PC, air compressor, tools, shipping and import tax. Partial kit is 999 EUR and full kit 1999 EUR.
Exploded view
Tap any part to see where to buy it. Diagram is schematic, not to scale.
Every part you need
| Part | Qty | Spec | Where to buy |
|---|---|---|---|
| StepperOnline EG17-G20 planetary gearbox 20:1 gearbox | 2 | EG series, NEMA 17, 20:1, backlash 20 arc-min or less, 5 mm input, 8 mm keyed output Precision reduction for two of the high load joints | StepperOnline: $36.36 (unverified) AliExpress: check price (unverified) pick EG17 20:1 variant |
| StepperOnline EG17-G10 planetary gearbox 10:1 gearbox | 1 | EG series, NEMA 17, 10:1, backlash 15 arc-min or less Reduction for the remaining geared joint | StepperOnline: $29.26 (unverified) AliExpress: check price (unverified) pick EG17 10:1 variant |
| StepperOnline 17HS08-1004S NEMA 17 stepper motor | 1 | 16 Ncm, 1.0 A, 42x42x20 mm, 4 wires (Stepper 1 in BOM) Small motor for the lightest joint | StepperOnline: $7.99 (unverified) AliExpress: check price (unverified) pick 17HS08-1004S variant |
| StepperOnline 17HS16-2004S1 NEMA 17 stepper motor | 3 | 45 Ncm, 2.0 A, 42x42x40 mm, 4 wires, 1 m cable with connector (Stepper 2 in BOM) Mid joints | StepperOnline: $9.13 (unverified) AliExpress: check price (unverified) pick 17HS16-2004S1 variant |
| StepperOnline 17HS24-2104S NEMA 17 stepper motor | 2 | 65 Ncm per BOM (StepperOnline page title now says 76 Ncm), 2.1 A, 42x42x60 mm, 4 wires (Stepper 3 in BOM) Highest torque joints | StepperOnline: $13.24 (unverified) AliExpress: check price (unverified) pick 17HS24-2104S variant |
| PAROL6 control board (Source Robotics) controller | 1 | Official board; sold with or without stepper drivers. PCB design is not open source Runs all 6 motors, sensors and the gripper; the only supported board | Source Robotics: EUR 199.00 no stepper drivers variant; with drivers variant 396 EUR |
| TMC5160 stepper driver module driver | 6 | Only the two listed TMC5160 modules are tested by the maker; needed only if the board is bought without drivers Drives each joint stepper | AliExpress: check price (unverified) AliExpress: check price (unverified) |
| Thermal paste or thermal cement thermal | 2 | Needed only if your control board has no drivers fitted Cools the driver chips | AliExpress: check price (unverified) |
| Mean Well EDR-120-24 DIN rail power supply power | 1 | 24 V 5 A 120 W; BOM accepts any 24 V 5 A supply Main power for motors and electronics | StepperOnline: $18.87 (unverified) TRC Electronics: $29.57 AliExpress: check price (unverified) |
| ST-Link V2 programming adapter programmer | 1 | SWD pin order must be SWCLK, SWDIO, GND, 3V3, 5V; official adapter recommended Flashes the control board firmware | Source Robotics: EUR 25.00 adapter, cable and ST-Link V2 AliExpress: check price (unverified) |
| USB B cable cable | 1 | PC to robot communication Connects the PC running Commander | Adafruit: $3.95 single, 1 m A to B |
| On/off push button 12 mm switch | 1 | 12 mm, 3 to 6 V Power button | AliExpress: check price (unverified) |
| JST PH 2.0 mm 4 pin cable 200 mm cable | 1 | For the power button Wires the button to the board | AliExpress: check price (unverified) |
| Noctua NF-A4x20 5V 40 mm fan fan | 1 | Or any 40 mm 5 V fan Cools the electronics | Watercooling UK: GBP 13.57 (unverified) |
| GX16 2 pin power connector, male and female connector | 1 | Panel power input Detachable power input | AliExpress: check price (unverified) |
| M8 4 pin female sensor connector connector | 1 | Gripper electrical connector Plugs in an electric gripper | AliExpress: check price (unverified) |
| XT30 female connector connector | 1 | Delivers power to the PAROL6 PCB Board power input | AliExpress: check price (unverified) |
| Limit switch ZW12-3 sensor | 3 | Type ZW12-3 Homing for three joints | AliExpress: check price (unverified) |
| Inductive sensor 4 mm NPN NO sensor | 1 | Inductive sensor 1 in BOM Homing sensor | AliExpress: check price (unverified) AliExpress: check price (unverified) |
| Inductive sensor GX-F8A sensor | 1 | Inductive sensor 2 in BOM Homing sensor | AliExpress: check price (unverified) |
| Inductive sensor M5 NPN NO sensor | 1 | Inductive sensor 3 in BOM Homing sensor | AliExpress: check price (unverified) AliExpress: check price (unverified) |
| Emergency stop button safety | 1 | Any normally closed (NC) e-stop, 19 mm in reference image Cuts motion in an emergency | AliExpress: check price (unverified) |
| PG7 cable gland hardware | 1 | For the e-stop cable Strain relief | AliExpress: check price (unverified) |
| M3 brass heat-set insert, 6 mm long hardware | 4 | M3, 6 mm length Threads in printed parts | AliExpress: check price (unverified) |
| HTD 3M closed belt 396 mm, 6 mm wide belt | 1 | Joint 1 belt: HTD3 396 Joint 1 drive | AliExpress: check price (unverified) pick 396 mm, 6 mm |
| HTD 3M closed belt 342 mm, 6 mm wide belt | 1 | Joint 3 belt: HTD3 342 Joint 3 drive | AliExpress: check price (unverified) pick 342 mm, 6 mm |
| HTD 3M closed belt 201 mm, 6 mm wide belt | 1 | Joint 4 belt: HTD3 201 Joint 4 drive | AliExpress: check price (unverified) pick 201 mm, 6 mm |
| HTD 3M closed belt 246 mm, 6 mm wide belt | 1 | Joint 5 belt: HTD3 246 Joint 5 drive | AliExpress: check price (unverified) pick 246 mm, 6 mm |
| HTD 3M 12 tooth pulley, 5 mm bore pulley | 2 | 5 mm bore, 10 mm pulley width per BOM (belts are 6 mm wide); J4 and J5 pulleys Motor pulleys | AliExpress: check price (unverified) pick 12T, 5 mm bore |
| HTD 3M 15 tooth pulley, 5 mm bore pulley | 1 | 5 mm bore, 10 mm pulley width per BOM (belts are 6 mm wide); J1 pulley Joint 1 motor pulley | AliExpress: check price (unverified) pick 15T, 5 mm bore |
| Shaft coupler, 8 mm bore coupler | 3 | 8 mm shaft hole, M4 screw holes Couples gearbox outputs | AliExpress: check price (unverified) |
| AXK3552 needle thrust bearing with washers bearing | 1 | 35x52x4, must include top and bottom plates Joint 1 axial load | AliExpress: check price (unverified) |
| NSK HR32906J tapered roller bearing bearing | 5 | Joints 3, 4 and 5 Main joint bearings | AliExpress: check price (unverified) pick HR32906J |
| NSK HR32907J tapered roller bearing bearing | 4 | Joints 1 and 2 Main joint bearings | AliExpress: check price (unverified) pick HR32907J |
| Ball bearing 3x8x4 bearing | 20 | Belt tension bearings Belt idlers | AliExpress: check price (unverified) |
| Ball bearing 3x10x4 bearing | 20 | Belt tension bearings Belt idlers | AliExpress: check price (unverified) |
| PM 4 mm pneumatic bulkhead connector pneumatic | 4 | 4 mm, type PM, in the robot Routes air through the arm | AliExpress: check price (unverified) |
| MHZ2-16D pneumatic parallel gripper pneumatic | 1 | Double acting, 16 mm bore Default end effector | AliExpress: check price (unverified) |
| PC4-M5 push fitting pneumatic | 2 | 4 mm tube to M5 thread Connects the gripper to tubing | AliExpress: check price (unverified) |
| Pneumatic tube 4x2.5 mm pneumatic | 5 meters | 4 mm OD, 2.5 mm ID; BOM quantity says 5 meters while its description says 1 meter, so 5 m is the safe buy Air lines | AliExpress: check price (unverified) |
| 5/2 solenoid air valve 24 V pneumatic | 1 | 5/2 way, 24 V coil, 4 mm tube connectors Switches the gripper | AliExpress: check price (unverified) |
| Suction cup gripper vacuum | 1 | Vacuum gripper option Alternative end effector | AliExpress: check price (unverified) |
| Vacuum generator vacuum | 1 | Vacuum gripper option Makes suction from compressed air | AliExpress: check price (unverified) |
| 4 mm to 6 mm tube coupler vacuum | 1 | Vacuum gripper option Joins tube sizes | AliExpress: check price (unverified) |
| M4x10 socket head cap screw fastener | 20 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x8 low head screw fastener | 10 | 2 mm head height per BOM; button head is the closest common match, check head height Assembly where head clearance is tight | Fastenere: check price (unverified) choose length and pack size |
| M3x8 socket head cap screw fastener | 50 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x14 socket head cap screw fastener | 30 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3 nut fastener | 10 | BOM row lists M3 nut Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x25 socket head cap screw fastener | 10 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M2x10 socket head cap screw fastener | 10 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x16 socket head cap screw fastener | 10 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x6 pan head Phillips screw fastener | 10 | Pan head Phillips Assembly | Source Robotics: check price (unverified) full PAROL6 screw kit (49 EUR, see Kits); no single M3x6 pan head page found |
| M3x12 socket head cap screw fastener | 30 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x35 socket head cap screw fastener | 10 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M4x16 socket head cap screw fastener | 30 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M4x14 socket head cap screw fastener | 10 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M4x50 socket head cap screw fastener | 10 | DIN 912 / ISO 4762 Assembly | Fastenere: check price (unverified) choose length and pack size |
| M3x15 countersunk screw fastener | 2 | Tapered (countersunk) head Assembly | Fastenere: check price (unverified) choose length and pack size |
| Dowel pin 4x18 mm small-bed | 3 | Only for small print beds: joins split J1 turret; solid steel Aligns split printed parts | AliExpress: check price (unverified) pick 4x18 mm |
| Dowel pin 6x22 mm small-bed | 4 | Only for small print beds: joins split upper arm Aligns split printed parts | AliExpress: check price (unverified) pick 6x22 mm |
| Two part epoxy, 1:1 slow set small-bed | 1 | Only for small print beds Bonds split printed parts | AliExpress: check price (unverified) |
Quantities follow the official PAROL6 docs: https://source-robotics.github.io/PAROL-docs/. "Unverified" prices come from search listings or older BOMs that we could not confirm on the seller's product page.
Kits (fewer orders, check what they leave out)
| Kit | Price | Includes | Leaves out | Buy |
|---|---|---|---|---|
| PAROL6 partial KIT Source Robotics | EUR 999.00 | Hard to find parts: control board, printed parts, bearings, belts, sensors, screws and the rest of the BOM | Gearboxes, stepper motors and power supply | Source Robotics: EUR 999.00 |
| PAROL6 Robotic arm KIT Source Robotics | EUR 1,999.00 | All parts to assemble the arm yourself | Out of stock on 2026-10-25 | Source Robotics: EUR 1,999.00 |
| PAROL6 Screw Kit Source Robotics | EUR 49.00 | Screws and nuts for the build | Everything else | Source Robotics: EUR 49.00 |
| PAROL6 3D Printed Parts KIT Source Robotics | EUR 400.00 | All printed parts (black in stock) | Electronics, motors, hardware | Source Robotics: EUR 400.00 |
3D printed parts
Needed. All structural parts are printed. Split versions of J1 turret and upper arm exist in STL/SMALL_PRINT_BED for small beds (needs dowel pins and epoxy). Files: https://github.com/PCrnjak/PAROL6-Desktop-robot-arm/tree/main/STL
Mistakes builders make
- The control board PCB is not open source: you must buy it from Source Robotics, and it has sold out before (issue 8).
- Use BOM.md in the repo; the PDF BOM is legacy and no longer updated (issue 18).
- Board comes with or without drivers: only buy TMC5160 drivers and thermal paste if you take the no-driver version.
- Build docs disagree on J4 output pulley orientation; check the homing pin lines up with the hole pattern before gluing anything (issue 15).
- If joints run the wrong way during homing, swap that motor's phase wires or flip direction in code, then tune homing (issue 13).
- Some AliExpress links only let you buy one unit or point at changed listings; check variant and quantity before paying (issue 17).
FAQ
How much does it cost to build the PAROL6?
About $750 to $1,150 in parts at current prices, DIY sourcing per BOM.md: official control board, 6 steppers, 3 EG gearboxes, bearings, belts, sensors, pneumatic gripper, screws, about 3 kg filament. Excludes 3D printer, PC, air compressor, tools, shipping and import tax. Partial kit is 999 EUR and full kit 1999 EUR..
Do I need a 3D printer for the PAROL6?
Yes. All structural parts are printed. Split versions of J1 turret and upper arm exist in STL/SMALL_PRINT_BED for small beds (needs dowel pins and epoxy).
Is there a kit for the PAROL6?
Yes: Source Robotics, Source Robotics, Source Robotics, Source Robotics. Check what each kit leaves out before ordering.
Buying guides for this build
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Last checked 2026-10-25. Sources: github.com · source-robotics.github.io · source-robotics.com · github.com · github.com · github.com · github.com · github.com