How to Build a 5-Axis Robot Arm with an Arduino (Beginner Friendly)
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| Fully Assembled Robot Arm |
Building a robot arm might sound like an ambitious first robotics project, but it doesn't have to be.
With a 3D printer, an Arduino Uno and a handful of affordable hobby servos, you can build a fully functional five-axis robot arm while learning the fundamentals of mechanics, electronics and programming.
This project was designed with beginners in mind. There are no custom PCBs, expensive components or specialist tools required. Instead, the focus is on building something that is easy to assemble, easy to understand and, most importantly, easy to improve.
Like any engineering project, this robot didn't work perfectly the first time. In fact, solving the problems taught me just as much as building it. Rather than hiding those mistakes, I've included them here so you can avoid the same issues when building your own.
By the end of this guide, you'll have everything you need to build your own robot arm and a solid foundation for future robotics projects.
Everything required to replicate this project can be found at the bottom of this post.
Parts Required
The robot is built using inexpensive, readily available components that are ideal for a beginner robotics project.
Electronics
- Arduino Uno
- 5 × MG90S Metal Gear Servos
- 5–6V Bench Power Supply
- 3 × 1000µF 16V Electrolytic Capacitors
- Breadboard
- Jumper wires
Hardware
- 3D printed robot arm parts
- M3 screws and nuts
- Servo mounting screws
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| All Required Parts |
Assembly
First 3d print all the parts, I would go with an infill of 10% to reduce the weight as much as possible.
Assembly starts at the base and gradually works upwards until the complete arm is assembled. Building it in this order makes the process much easier, as each section supports the next.
Step 1 – Assemble the Base
Begin by attaching the base servo into the lower base section using the supplied servo screws.
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| Base |
Then assemble the base of the arm
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| Arm Base |
Step 2 – Install the Shoulder
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| Shoulder Part |
Mount the shoulder servos into the main arm support and connect the two halfs together with the spacer.
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| Shoulder Arm Section assembled |
Attach the upper arm section to the servo horn, taking care not to move the servo away from its centred position.
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| Shoulder Connected To Base |
Before tightening the hardware completely, gently move the arm by hand to ensure nothing binds or catches.
Step 3 – Assemble the Elbow
Collect the Elbow Parts
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| Elbow Parts |
Assemble each part so it looks like the picture below.
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| Elbow Assembled |
Install the elbow servo into the upper arm and attach the forearm section.
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| Elbow connection |
Again, check that the joint moves freely before fully tightening the screws.
The elbow supports less weight than the shoulder, but smooth movement is still important for reliable operation.
Step 4 – Install the Wrist
Collect the write parts
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| Wrist Part |
Assemble the components as per the picture below
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| Wrist components assembled |
Mount the wrist servo before attaching the wrist bracket.
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| Wrist connected |
Then mount the hand part on the wrist section
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| Hand Connected to Wrist |
This joint controls the angle of the gripper and should rotate smoothly without any excessive play.
Ensure the servo cable is routed neatly through the arm before moving on.
Step 5 – Assemble the Gripper
Collect the Gripper Parts
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| Gripper Parts |
Finally, assemble the gripper before attaching it to the wrist servo.
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| Grippers Assembled |
Now Attach to the hand of the robot arm
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| Gripper Connected |
Check that both jaws move freely and that nothing fouls during opening and closing.
Once attached, verify the gripper opens and closes correctly by rotating the servo gently by hand.
Step 6 – Wiring
The Arduino Uno controls all five servos directly, while the servos are powered from a separate 5–6V power supply. This prevents the Arduino from being overloaded by the current required to drive the motors.
Connect the Yellow/Orange servo wires as follows to the Arduino Uno:
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| Pin Connections |
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| Wiring |
Step 7 – Final Inspection
Before powering the robot for the first time, carry out one final inspection.
Check:
- Every screw is fully tightened.
- All servo horns are secure.
- Each joint moves freely by hand.
- Servo cables cannot snag during movement.
- The wiring matches the wiring diagram.
- The Arduino and servo power supplies share a common ground.
Spending a few minutes checking everything now can save a lot of troubleshooting later.
💡 Builder's Tip: Don't fully tighten the screws until you've checked the joint moves freely. A little extra friction can significantly reduce the lifting ability of small hobby servos.
First Program
With the robot fully assembled, it's time to upload the control program. This can be found at the end of the blog post.
The first sketch simply moves each joint, allowing you to confirm that every servo is connected correctly and rotating in the expected direction.
Watching the robot move for the first time is a satisfying moment, but don't worry if everything isn't perfect straight away.
Mine certainly wasn't.
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| Robot arm control Program |
Troubleshooting
The first problem appeared when I asked the robot to lift an object.
Although every joint moved correctly, the shoulder struggled once the gripper was attached.
Removing the gripper immediately made lifting much easier, confirming the servo wasn't faulty. The shoulder simply carries the greatest load because it supports every component further along the arm.
While investigating further, I noticed my bench power supply switching into CC (Constant Current) mode whenever the shoulder moved.
After checking the power supply manual, I realised the current limit had been set far too low. Increasing the current limit immediately improved the robot's lifting ability.
Although much better, the movement was still a little hesitant when several servos started moving together.
To improve the power supply stability, I added three 1000µF electrolytic capacitors across the servo supply rails. These help reduce short voltage dips during sudden bursts of current demand.
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| Adding Capacitors |
After fitting them, the robot was finally able to lift and move the wooden blocks it had been designed for.
The biggest lesson from this project wasn't about programming—it was understanding how mechanical loading and power delivery work together. Sometimes the solution isn't changing the code at all.
What I Learned
Every project teaches something, and this one was no exception.
The biggest lessons were:
- Always centre servos before assembly.
- Check every joint moves freely.
- Use a separate power supply for the servos.
- Make sure your bench power supply isn't limiting the available current.
- Bulk capacitors can improve stability during sudden current demands.
- The shoulder joint experiences the greatest load, so even small increases in weight have a noticeable effect.
Robotics is far more than writing code. Good mechanical design, reliable electronics and well-structured software all play an equally important role.
Where to Go Next
Once you've built the robot, the learning doesn't stop there.
This design provides an excellent platform for experimenting with more advanced robotics projects, including:
- Joystick control
- Motion recording and playback
- Automatic homing
- Inverse kinematics
- Pick-and-place routines
- Camera vision
- AI-assisted object recognition
One of the best parts of building your own robot is that you can continue improving it as your skills develop.
Build Your Own
Everything you need to build this robot is available below.
Downloads include:
If you build one, I'd genuinely love to see it. Feel free to modify the design, improve it and make it your own. Every improvement helps the project evolve and may inspire future versions.
Final Thoughts
Building this robot arm reinforced something I've found to be true with almost every engineering project: the first version is rarely perfect.
The important part isn't getting everything right the first time—it's understanding why something doesn't work and improving it.
This project combines 3D printing, electronics, programming and problem-solving into a single beginner-friendly build that teaches skills you can apply to far more advanced robots in the future.
If you've been looking for a practical introduction to robotics, I hope this project gives you the confidence to get started. Download the files, build your own robot arm, and don't be afraid to experiment along the way. That's where the real learning happens.
Happy building!
Matty
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