[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"project-72293":3},{"id":4,"name":5,"fullName":6,"owner":7,"repo":5,"description":8,"homepage":8,"htmlUrl":8,"language":9,"languages":8,"totalLinesOfCode":8,"stars":10,"forks":11,"watchers":12,"openIssues":13,"contributorsCount":14,"subscribersCount":14,"size":14,"stars1d":15,"stars7d":15,"stars30d":15,"stars90d":14,"forks30d":14,"starsTrendScore":16,"compositeScore":17,"rankGlobal":8,"rankLanguage":8,"license":18,"archived":19,"fork":19,"defaultBranch":20,"hasWiki":19,"hasPages":19,"topics":21,"createdAt":8,"pushedAt":8,"updatedAt":22,"readmeContent":23,"aiSummary":24,"trendingCount":14,"starSnapshotCount":14,"syncStatus":25,"lastSyncTime":26,"discoverSource":27},72293,"low_cost_robot","AlexanderKoch-Koch\u002Flow_cost_robot","AlexanderKoch-Koch",null,"Python",3394,300,56,18,0,1,3,29.44,"MIT License",false,"main",[],"2026-06-12 02:03:01","# Low-Cost Robot Arm\nJoin the waitlist here to get all the parts in one package: https:\u002F\u002Ftau-robotics.com\u002Frobots\n\nThis repository contains the files to build and control a low-cost robot arm that costs about $250. You can also build a second robot arm (the leader arm) to control the other arm (the follower arm) that costs about $180, for a total of $430. The design of the leader is inspired by the [GELLO project](https:\u002F\u002Fgithub.com\u002Fwuphilipp\u002Fgello_mechanical) but is simpler to build. Such a robot arm is well suited for [robot learning](https:\u002F\u002Fx.com\u002Falexkoch_ai\u002Fstatus\u002F1756500716854841835?s=20). Two of those arms are also capable of [folding clothes](https:\u002F\u002Fx.com\u002Falexkoch_ai\u002Fstatus\u002F1772750496174149708?s=20).\n\nThis robot arm uses Dynamixel XL430 and Dynamixel XL330 servo motors. The XL430 motors are almost twice as strong and are used for the first two joints.\nThe XL330 motors are weaker but weigh only 18g each. This makes the arm very lightweight and fast.\nDynamixel sells the U2D2 adapter to connect the servos to a computer. However, this is very expensive and the latency is very high. This build uses another cheaper adapter board instead.\nThe robot arm can be controlled with the Dynamixel SDK: ```pip install dynamixel-sdk```\n\n![Robot Arm](.\u002Fpictures\u002Frobot_portait.jpg)\n\n## Follower Arm\n\n### Required Materials\n\n| Part                          | Cost | Buying link                                    | Specs |\n|-------------------------------|------|------------------------------------------------| --- |\n| 2x Dynamixel XL430-W250       | $100 | https:\u002F\u002Fwww.robotis.us\u002Fdynamixel-xl430-w250-t\u002F | https:\u002F\u002Femanual.robotis.com\u002Fdocs\u002Fen\u002Fdxl\u002Fx\u002Fxl430-w250\u002F |\n| 4x Dynamixel XL330-M288       | $96  | https:\u002F\u002Fwww.robotis.us\u002Fdynamixel-xl330-m288-t\u002F | https:\u002F\u002Femanual.robotis.com\u002Fdocs\u002Fen\u002Fdxl\u002Fx\u002Fxl330-m288\u002F|\n| XL330 Idler Wheel             | $10  | https:\u002F\u002Fwww.robotis.us\u002Ffpx330-h101-4pcs-set\u002F   | **Note**: pack of four; three needed for  longer version pictured above (with elbow-to-wrist extension), two needed for shorter version shown in the [assembly video](https:\u002F\u002Fyoutu.be\u002FRckrXOEoWrk)|\n| XL430 Idler Wheel             | $7   | https:\u002F\u002Fwww.robotis.us\u002Fhn11-i101-set\u002F          | |\n| Waveshare Serial Bus Servo Driver Board | $10  | https:\u002F\u002Fa.co\u002Fd\u002F7C3RUYU                         | |\n| Voltage Reducer               | $10   | https:\u002F\u002Fa.co\u002Fd\u002Fcy02ADW                         | **Note**: pack of six, only one needed per follower arm |\n| 12V Power Supply              | $12  | https:\u002F\u002Fa.co\u002Fd\u002F40o8uMN                         | |\n| Table Clamp                   | $6   | https:\u002F\u002Fa.co\u002Fd\u002F4KEiYdV                         | |\n| Wires                         | $7   | https:\u002F\u002Fa.co\u002Fd\u002FhQfk2cb                         | |\n| Total                         | $258 |                                                | |\n\nThere is usually a 10% discount code for the Robotis shop. It might also help to add some grip tape to the gripper (e.g. https:\u002F\u002Fa.co\u002Fd\u002FdW7BnEN). A USB-C cable is necessary to connect the servo driver board to a computer.\n\n![follower](.\u002Fpictures\u002Ffollower_arm.png)\n\n### Assembly\n\nVideo of the assembly: https:\u002F\u002Fyoutu.be\u002FRckrXOEoWrk\n\n1. Print all parts with a 3D printer\n   1. The STL files are in `hardware\u002Ffollower\u002Fstl`\n   2. The parts are designed to be easy to print; only the moving part of the gripper needs supports\n2. Scanning motors\n   1. Connect the driver board to a computer (should work with Linux and MacOS)\n   2. Figure out the device name (e.g. tty.usbmodem57380045631 for MacOS): ```ls \u002Fdev\u002Ftty.*```\n   3. Scan each motor individually with [Dynamixel Wizard](https:\u002F\u002Femanual.robotis.com\u002Fdocs\u002Fen\u002Fsoftware\u002Fdynamixel\u002Fdynamixel_wizard2\u002F)\n      1. Set the baudrate to 1M for all motors\n      2. Set the servo IDs to 1 for the shoulder to 5 (6 if using the elbow-to-wrist extension) for the gripper servo\n3. Assembly\n   1. Assemble the arm without the base\n      1. Make sure that the servos are fixed in the same position as in the CAD\n      2. The servo horn should be in the default position when screwed in\n   2. Solder wires onto voltage reducer; input should be connected to female connectors and the output to male connectors\n   3. Screw the voltage reducer and the servo driver board onto the base\n   4. Screw the base onto the arm\n   5. Connect D, V, and G ports on the driver board to the shoulder rotation servo\n   6. Connect the shoulder rotation servo to the shoulder lift servo\n   7. Connect the input for the voltage reducer to V and G ports on the driver board\n   8. Connect the output of the voltage reducer and the remaining D port of the driver board to the elbow servo\n   9. Connect the driver board to the power supply\n   10. Connect to an XL330 servo and view the input voltage on Dynamixel Wizard, then adjust the screw on the voltage reducer until the input voltage is 5V\n\n## Leader Arm\n\n### Required Materials\n\n| Part                          | Cost | Buying link | Specs |\n|-------------------------------|------| --- | --- |\n| 6x Dynamixel XL330-M077       | $144 |  https:\u002F\u002Fwww.robotis.us\u002Fdynamixel-xl330-m077-t\u002F | https:\u002F\u002Femanual.robotis.com\u002Fdocs\u002Fen\u002Fdxl\u002Fx\u002Fxl330-m077\u002F|\n| XL330 Frame | $7   | https:\u002F\u002Fwww.robotis.us\u002Ffpx330-s101-4pcs-set\u002F | |\n| XL330 Idler Wheel             | $10  | https:\u002F\u002Fwww.robotis.us\u002Ffpx330-h101-4pcs-set\u002F   | **Note**: pack of four; three needed for longer version (with elbow-to-wrist extension), two needed for shorter version pictured below |\n| Waveshare Serial Bus Servo Driver Board | $10  | https:\u002F\u002Fa.co\u002Fd\u002F7C3RUYU | |\n| 5V Power Supply               | $6   | https:\u002F\u002Fa.co\u002Fd\u002F5u90NVp | |\n| Table Clamp                   | $6   | https:\u002F\u002Fa.co\u002Fd\u002F4KEiYdV | |\n| Total                        | $183 | | |\n\n![leader](.\u002Fpictures\u002Fleader_arm.png)\n\n### Assembly\n\nThe assembly of the leader arm is simpler since all motors use 5V. The gripper is replace by a handle and a trigger. During use, a small torque can be applied to the trigger so that it opens by default. The GELLO design uses a spring for this purpose but it is much more difficult to assemble.\nThe `teleoperation.py` script can be used to test the arms. However, the device names might have to be adjusted.\n\n## Simulation\nA basic simulation environment in MuJoCo is available by running `simulation.py`.\n","该项目提供了一套构建和控制低成本机械臂的方案，总成本约为250美元。核心功能包括使用Dynamixel XL430和XL330伺服电机实现精确控制，其中XL430用于前两个关节以增强力量，而XL330则因其轻量级特性（仅18克）被用于其他部分，使得整个机械臂既轻便又快速。此外，项目还支持构建一个额外的“领导者”机械臂来操控另一个“跟随者”机械臂，适用于机器人学习及衣物折叠等应用场景。通过采用更经济实惠的适配器板替代官方高价且高延迟的U2D2适配器，进一步降低了成本。该机械臂可通过Dynamixel SDK进行编程控制。",2,"2026-06-11 03:41:12","high_star"]