Building a motorized welding turntable solves a common problem: welding around circular or cylindrical objects without walking around the workpiece. Greenhill Forge’s project creates a large motorized lazy Susan with adjustable speed and a modest budget. The table rotates the piece under the torch, so the welder stays still and both hands are free to guide the arc.

The heart of the system is a stepper motor mounted under the table surface. Rotation passes through a gear reducer and a standard spider coupling, which transmits motion to the top plate. The reducer increases torque and lowers speed, so the table moves smoothly even with heavy parts. Everything is controlled by an Arduino UNO Rev3 board, which drives the motor and reads user commands.

Speed control and user interface

The user adjusts rotation speed with a rotary encoder. The knob is comfortable to use even with welding gloves. A small OLED screen shows the set speed, so control is immediate and precise. The firmware on the Arduino UNO reads the encoder, updates the display, and drives the stepper motor with the correct pulse frequency.

For those who want to replicate the project, choosing components is straightforward. A Uno R3 with ATmega328 is the same board used in the original project. A NEMA 17 stepper motor rated at 1.2 A has the right torque for a table of this size, which rotates through a reducer anyway. A 12 mm rotary encoder with knob connects directly to digital pins and can be turned even with welding gloves. Finally, a 128×64 OLED display shows parameters clearly.

• Stepper motor with gear reducer for torque
• Spider coupling to connect shaft and table
• Lazy Susan bearing for rotating support
• Rotary encoder for adjustment
• OLED display for visual feedback

Grounding through the shaft

An important detail is grounding management. In welding, current must return to the generator through the workpiece. If the turntable is not grounded, current passes through the lazy Susan bearings, causing arcs that damage them quickly. Greenhill Forge solves the problem with a ground strap that runs through the motor shaft.

The strap maintains conductivity between the table surface and the workpiece. This way, welding current has a dedicated path and the bearings stay protected. The strap is a wear item, but with normal use it should last a long time. Also, replacement cost is minimal, so maintenance stays economical.

The project is documented in a Greenhill Forge video, which follows the entire process: cutting and welding the frame, mounting the motor under the table, and grounding. At the end, the table is shown in action during a real weld, with speed adjusted on the fly.

Why build a turntable

This project appeals to both beginners and experienced welders. Construction is simple and requires few tools. Moreover, electronic control with Arduino UNO opens the door to future modifications, such as programmed rotation or foot pedal control. The modest cost makes the project accessible to many makers.

The welding turntable is an example of how a stepper motor, an encoder, and an OLED display can turn a simple support into a professional tool. Well-designed grounding protects components and ensures quality welds. Finally, adjustable speed lets you adapt rotation to any type of work.

Source: https://youtu.be/WQSzLMcc9zQ?si=DB7dDrRwHsfXU1OI

Related products

• 12mm rotary encoder with knob

The post Motorized welding turntable with Arduino UNO appeared first on Open Electronics.

Those just starting out in 3D printing often believe that their next major purchase after the printer will be a 3D scanner. If you’re going to get something that can print a three dimensional model, why not get something that can create said models from real-world objects? But the reality is that only a small percentage ever follow through with buying the scanner; primarily because they are notoriously expensive, but also because the scanned models often require a lot of cleanup work to be usable anyway.

While this project by [Travis Antoniello] won’t make it any easier to utilize scanned 3D models, it definitely makes them cheaper to acquire. So at least that’s half the battle. Consisting primarily of a stepper motor, an Arduino, and a EasyDriver controller, this is a project you might be able to assemble from the parts bin. Assuming you’ve got a pretty decent camera in there, anyway…

The general idea is to place a platform on the stepper motor, and have the Arduino rotate it 10 degrees at a time in front of a camera on a tripod. The camera is triggered by an IR LED on one of the Arduino’s digital pins, so that it takes a picture each time the platform rotates. There are configurable values to give the object time to settle down after rotation, and a delay to give the camera time to take the picture and get ready for the next one.

Once all the pictures have been taken, they are loaded into special software to perform what’s known as photogrammetry. By compiling all of the images together, the software is able to generate a fairly accurate 3D image. It might not have the resolution to make a 1:1 copy of a broken part, but it can help shave some modeling time when working with complex objects.

We’ve previously covered the use of photogrammetry to design 3D printed accessories, as well as a slightly different take on an automated turntable a few years ago. The process is still not too common, but the barriers to giving it a try on your own are at least getting lower.

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