Asked — Edited

The Birth Of The XR-1 DIY Robot

Introducing the Updated XJ-5: A New Class of Hobby Robots

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The XJ-5 robot platform, available at Robots Builder, is known for its user-friendly design, emphasizing accessibility and ease of assembly. Designed to make robotics more approachable, the XJ-5 is meticulously engineered for simple 3D printing and assembly using standard components such as servos and bearings.

Our objective is to simplify the building process so that enthusiasts and robot hobbyists of all skill levels can engage in constructing their own robots. We've dedicated significant time to perfecting the design, enabling users to quickly progress to the exciting tasks of programming and teaching their robots using Synthiam's ARC software. The XJ-5 is highly customizable, featuring a variety of hands and heads to allow personalization of each creation. To foster a collaborative and open community, we're proud to announce that the XJ-5 is entirely open source, inviting users to contribute, modify, and share their innovations globally. Get ready to embark on a journey of creativity and exploration with the XJ-5!

For more information, check out Robots Builder.

As a creator of the XJ-5 and our other XR series, I will be utilizing the Synthiam ARC platform for robot control, and I hope others here will join me in developing an ARC project to support the XJ-5 robot. As of January 9th, 2024, we have started posting files for 3D printing. Meanwhile, we are developing documentation and updating the website, so please check back regularly.

My goal is to develop a walking, talking, listening, and seeing robot the size of a small child using ARC and its various features. As I progress, I will be sharing more about my efforts here.

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Now, let's delve into the project, focusing on the new and improved XR1, the XJ-5, which I have been designing and building over the past year.

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As a young enthusiast, I loved the movie Short Circuit and was inspired by the Johnny 5 robot, motivating me to create a similar robot. Although not a direct replica of Johnny 5, it embodies some of its iconic features. About a year ago, DJ suggested opting for a robot with wheels or tracks over a bipedal robot due to the complexity of achieving stable walking, a challenge I am familiar with from our XR2 project. But that's a story for another time.

Now, in May 2025, I've nearly completed the assembly and will soon start implementing ARC and the AI brain I've been developing to enhance ARC support. Expect more updates soon.

I have started building the robot's torso from the hips up, as shown in the pictures below. The shoulders are not entirely installed because I'm awaiting the arrival of the correct screws. Please excuse the messy workbench.

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To support the robot, I've designed a set of custom boards with ARC firmware that will connect to the onboard PC, located in the chest area.

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The above board will be mounted on the backplate between the two shoulder sockets and connected to a USB hub linked to the PC. Two additional USB cables, alongside servo power, run down to the boards in each hand. The USB camera and headboard will connect to the PC's other two USB ports. ARC will operate headlessly on the Windows 11 Pro PC using RDP for remote connectivity. Additionally, there's an MPU connected to the main board, which I plan to leverage with ARC.

I've added the shoulders and arms down to the wrists, ensuring they are strong and capable.

I've decided to create a Johnny 5-style head for my build featuring two cameras. Here's the completed head. I've included six more servos for the eye flaps, bringing the total count to 50 servos. The design incorporates a directional mic array and ultrasonic radar for enhanced audio and visual capabilities. For sound, two speakers are mounted in the head with an audio amplifier.

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I've also opted to integrate a 5-inch touch display into the XR-1, as shown below.

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This display will offer additional options for operator interaction using ARC remote controls.

I've created both two and three-finger claw grippers and human-like hands, providing versatility in interaction for the XR-1.

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#17  

Thanks for sharing! I really appreciate a new open source bot out there.

PRO
Belgium
#18  

hi averyone

smiller29 very cool design .

ninck

remember that the cheap servo's dont have a full range of 1 to 180 degree . its more like 1-5 to 175-180  degree .

#19   — Edited

We are in the process of releasing a new set of legs that will not require leg covers and have better support for cable management.

draft of the design

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PRO
Synthiam
#20  

Ooooooh that's awesome - i'm glad you're still working on it! Take your time getting the physical components and build to your satisfactory level and it'll be ready by the time ARCx is ready fingers crossed. I keep getting in trouble every time I mention ARCx haha. I know it's a million+ lines of code being re-written and it's a lot of work but I'm eager to get you all using it!

#21  

DJ I am depending on ARCx so my fingers are crossed your team continues to have success with it’s development.

We have made a lot of improvements on the XR1. We have also created a feedback main board for using four wire servos for position feedback.

I currently have 51 servos and a bunch of sensors in my build so I have a lot to control and I need ARCx for the job. xD

#22   — Edited

As another option I have been making a Track based base option for the XR1 based on the J5 lower section.  It is not the same at all really other than the general concept.

This is going to be for builders that do not want to deal with all the challenges make the XR1 walk on two legs.

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I am currently printing the parts that design has been completed.    I can't wait to get this to the point I can setup my ARC project to control this unit.

PRO
Synthiam
#23  

That’s a great idea. I’d build that before a walking robot. I don’t have much interest in maintaining gaits and the challenges that come along with a walking robot.

I like that your robot has tracks like a walle. Will it have arms and grippers? Or a gripper?

PRO
Synthiam
#24  

This is a robot design I like. With the arm and gripper in the middle

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