Mobile ALOHA parts list
Discontinued: Trossen has discontinued the ViperX 300 S and WidowX 250 S arms this build uses, and the Tensorbook laptop is no longer sold. Check stock before buying any other part.
ALOHA's four Trossen arms on an AgileX Tracer base with a laptop and battery for whole body mobile teleoperation.
Mobile robotsadvanced by Zipeng Fu, Tony Zhao, Chelsea Finn (Stanford)
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 |
|---|---|---|---|
| Trossen ViperX 300 6DOF robot arm follower arm | 2 | 9 Dynamixels: 7x XM540-W270-T plus 2x XM430-W350-T. BOM link is the old non S version; Trossen now lists the ViperX 300 S, marked discontinued. Official BOM lists $6,129.95/unit. Follower arms on the base. | Trossen Robotics: $6,129.95 (unverified) Trossen Robotics: check price (unverified) |
| Trossen WidowX 250 6DOF robot arm leader arm | 2 | 9 Dynamixels: 7x XM430-W350-T plus 2x XL430-W250-T. Trossen now lists the WidowX 250 S, marked discontinued. Official BOM lists $3,549.95/unit. Leader arms the operator backdrives. | Trossen Robotics: $3,904.95 (unverified) Trossen Robotics: check price (unverified) |
| AgileX Tracer AGV base | 1 | Differential drive indoor base; connects to the laptop through the USB to CAN adapter that ships with it. Resellers now mostly list Tracer 2.0. Official BOM lists $6,999.95. Mobile base the whole rig rides on. | RobotLAB: $6,500.00 Robotics Center: $9,500.00 single (Tracer 2.0) Generation Robots: EUR 9,000.00 single (Tracer 2.0) |
| Lambda Labs Tensorbook laptop compute | 1 | Onboard compute running ROS and data collection. Lambda has wound down its hardware business, so expect to substitute a Linux laptop with a strong NVIDIA GPU. Official BOM lists $2,399.00. Runs teleop, recording and policies on board. | Lambda: check price (unverified) |
| 4040 aluminum extrusion 800 mm, 2 pcs per pack frame | 4 | BOM needs 8 beams. Official BOM lists $42.29/pack. Frame uprights. | Amazon: check price |
| 4040 aluminum extrusion 500 mm, 4 pcs per pack frame | 2 | BOM needs 6 beams. Official BOM lists $58.99/pack. Frame. | Amazon: check price |
| 4040 aluminum extrusion 400 mm, 1 pc per pack frame | 2 | BOM needs 2 beams. Official BOM lists $22.99/pack. Frame. | Amazon: check price |
| 4040 aluminum extrusion 300 mm, 4 pcs per pack frame | 2 | BOM needs 7 beams. Official BOM lists $59.99/pack. Frame. | Amazon: check price |
| 4040 L-shape connectors, 6 pcs per pack frame | 5 | BOM needs 28. Official BOM lists $32.99/pack. Frame joints. | Amazon: check price |
| 4040 T-shape connectors, 6 pcs per pack frame | 1 | BOM needs 4. Official BOM lists $30.99/pack. Frame joints. | Amazon: check price |
| 4040 45 degree corner connectors frame | 1 | Official BOM lists $21.99. Diagonal bracing. | Amazon: check price |
| 4040 corner brackets and T-slot sliding nuts set frame | 2 | Official BOM lists $24.99/set. Frame joints. | Amazon: check price |
| 4040 end caps frame | 2 | Official BOM lists $9.81/pack. Covers beam ends. | Amazon: check price |
| M6 x 20 mm screws fastener | 1 | Arms mount with M6, unlike the M8 frame screws. Official BOM lists $9.99. Bolts the arms to the frame. | Amazon: check price |
| M6 T-nuts for 4040 fastener | 2 | Official BOM lists $14.16/pack. Arm mounting nuts. | Amazon: check price |
| Logitech C922x Pro Stream webcam camera | 4 | BOM says 4, but the README and launch file run 3 cameras (front plus 2 wrist), so the 4th is a spare. Official BOM lists $98.35/unit. RGB views for imitation learning. | Amazon: check price Logitech: $119.99 |
| USB 3.0 hub, 7 port (VEMONT) hub | 2 | Hub 1: 4 arms, Tracer and front camera; hub 2: 2 wrist cams. Official BOM lists $19.99. Laptop has few ports. | Amazon: check price |
| Battery pack (portable power station at the BOM Amazon link) power | 1 | Rides on the bottom beams and powers the arm supply and laptop. The exact model at the BOM link could not be confirmed because the Amazon page did not load. Official BOM lists $699.00. Untethered power for arms and laptop. | Amazon: check price |
| 600W AC to 12V DC power supply (Anbull) power | 1 | Plugs into the battery pack. Official BOM lists $59.00. 12V for the four arms and U2D2 hub. | Amazon: check price |
| 12V DC extension cable, 10 ft, 14AWG, 5.5x2.1mm power | 5 | 4 for the arms plus 1 for the U2D2 Power Hub. Official BOM lists $15.99. Arm and hub power leads. | Amazon: check price |
| Fork spade connectors power | 1 | Official BOM lists $13.69. Terminates DC cables on the supply. | Amazon: check price |
| USB A to Micro USB cable cable | 4 | One per arm. Official BOM lists $17.87. Arm data links. | Amazon: check price |
| ROBOTIS DYNAMIXEL XL430-W250-T odometry | 2 | Used only as wheel encoders: remove the gear nearest the motor shaft so the wheel spins freely. Official BOM lists $49.90. Measures base velocity while the Tracer is powered off. | ROBOTIS: $27.50 RobotShop: CAD 101.84 (unverified) |
| ROBOTIS U2D2 odometry | 1 | Official BOM lists $32.10. USB link to the odometry Dynamixels. | ROBOTIS: $36.92 RobotShop: $46.76 (unverified) |
| ROBOTIS U2D2 Power Hub Board Set odometry | 1 | Official BOM lists $19.00. Powers the odometry Dynamixels at 12V. | ROBOTIS: $21.85 |
| Jumper wires odometry | 1 | Official BOM lists $9.99. Hub wiring. | Amazon: check price |
| Weights odometry | 1 | Placed on the odometry housing to keep the wheels in contact. Official BOM gives no clear price. Stops the encoder wheels slipping. | Amazon: check price |
| Rubber bands misc | 1 | For the leader arm gravity compensation redesign. Official BOM lists $9.99. Leader arm gravity comp. | Amazon: check price |
| Grip tape misc | 1 | Grippers plus the odometry wheels. Official BOM lists $54.14. Grip on fingers and encoder wheels. | Amazon: check price |
Quantities follow the official Mobile ALOHA docs: https://docs.google.com/document/d/1_3yhWjodSNNYlpxkRCPIlvIAaQ76Nqk2wsqhnEVM6Dc/edit. "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 |
|---|---|---|---|---|
| Mobile AI (successor to the Mobile ALOHA kit, WidowX AI arms) Trossen Robotics | check price | Trossen's packaged mobile bimanual platform; the page showed $33,695.95 and $40,025.80 for different configurations. | Not the original BOM arms or base; confirm configuration with Trossen. | Trossen Robotics: check price |
3D printed parts
Needed. Odometry unit: wheel x2, mount x2, housing x2. Grippers and wrist cam mounts come from the original ALOHA files (25 pieces). Frame design also on Vention. Files: https://drive.google.com/drive/folders/1AaGGKBlg5HtW-t8UebUBuyeS0otazlRP
Mistakes builders make
- Comment out the forward kinematics call in the Interbotix arm.py publish_positions function as the README says, or teleop slows down and record_episodes.py rejects episodes for running under 42 Hz (issue #18).
- Gripper motors overload and need a reboot if the current limit is left at default; set Current Limit on the follower gripper XM430-W350 in Dynamixel Wizard, and users report the limit is not always respected (issues #6 and #7).
- Logitech C922 cameras can drop to 30 fps at 640x480 or about 10 fps at 720p under Ubuntu 20.04 even though they run fine on Windows (issue #36). Test frame rates before mounting.
- The guide routes all 4 arms through a USB hub because the laptop has few ports, while the README says never to use a hub for arms; users asked which is right (issue #8). Test link stability early.
- Follower joints twitching during teleop is reported with no posted fix (issue #22); check power and udev latency settings first.
- The Tracer torques its wheels when powered, so base velocity comes from the Dynamixel odometry wheels with the base off; strip the gear or the wheels slip.
- Arms mount with M6 screws and M6 T-nuts, not the M8 hardware used for the rest of the 4040 frame.
- Both arm models are discontinued at Trossen and the Tensorbook is no longer sold; price substitutes before committing.
FAQ
How much does it cost to build the Mobile ALOHA?
About $30,500 to $36,000 in parts at current prices, Arms about $20,070, Tracer $6,500 to $9,500, laptop $2,400 plus. BOM list total was $31,757.86. Excludes 3D printer, filament, Allen keys, hot glue gun, shipping and tax..
Do I need a 3D printer for the Mobile ALOHA?
Yes. Odometry unit: wheel x2, mount x2, housing x2. Grippers and wrist cam mounts come from the original ALOHA files (25 pieces). Frame design also on Vention.
Is there a kit for the Mobile ALOHA?
Yes: Trossen Robotics. Check what each kit leaves out before ordering.
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Last checked 2026-10-25. Sources: docs.google.com · github.com · github.com · github.com · github.com · github.com · github.com · www.trossenrobotics.com · www.trossenrobotics.com · lambda.ai