Hackaday Prize 2023: PAROL6 – A GPL Desktop Robotic Arm

August 15, 2023 by Dave Rowntree 8 Comments

Parol 6 is a 3D-printed six-axis robot arm created by [Petar Crnjak] as a combination of the principles from a few previous projects. Aside from a pneumatic gripper, each axis is driven by a stepper motor, with at least a few of these axes being driven through a metal planetary gearbox for extra precision and torque.

From what we can glean from the work-in-progress documentation, there are some belt drives on four of the relevant axes and a mix of NEMA17 format steppers driving either 20:1 or 10:1 reduction boxes. There appears to be a mix of inductive sensors and traditional microswitches used, but it’s not so easy to work out where these are placed. Continue reading “Hackaday Prize 2023: PAROL6 – A GPL Desktop Robotic Arm” →

Laser Engraver Uses All Of The DVD Drive

August 10, 2023 by Bryan Cockfield 18 Comments

For the last ten to fifteen years, optical drives have been fading out of existence. There’s little reason to have them around anymore unless you are serious about archiving data or unconvinced that streaming platforms will always be around. While there are some niche uses for them still, we’re seeing more and more get repurposed for parts and other projects like this tabletop laser engraver.

The build starts with a couple optical drives, both of which are dismantled. One of the shells is saved to use as a base for the engraver, and two support structures are made out of particle board and acrylic to hold the laser and the Y axis mechanism. Both axes are made from the carriages of the disassembled hard drives, with the X axis set into the base to move the work piece. A high-output laser module is fitted to the Y axis with a heat sink, and an Arduino and a pair of A4988 motor controllers are added to the mix to turn incoming G-code into two-dimensional movement.

We’ve actually seen a commercial laser engraver built around the same concept, but the DIY approach is certainly appealing if you’ve got some optical drives collecting dust. Otherwise you could use them to build a scanning laser microscope.

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Wood game piece being carved by a CNC mill with a hacked rotary axis

This $12 CNC Rotary Axis Will Make Your Head Spin

May 15, 2023 by Michael Shaub 20 Comments

[legolor] brings us a great, cheap rotary axis to add to your small 3 axis CNC mills. How are you going to generate G-Code for this 4th axis? That’s the great part, and the hack, that [legolor] really just swapped the Y axis for the rotation. To finish the workflow and keep things ~~cheap~~ accessible to all there’s a great trick to “unwrap” your 3D model so your CAM software of choice thinks it’s still using a linear Y axis and keeps your existing workflow largely intact. While this requires an extra step in Blender to do the unwrapping, we love the way this hack changes as little of the rest of your process as possible. The Blender script might be useful for many other purposes too.

The results speak for themselves too! We thought the 3D printed parts were suspect in a CNC setup, but for the small scale of game pieces and milling wood, the setup is stable enough to produce a surprisingly accurate and detailed finish. If you want to try the same approach with something larger or a tougher material, [legolor] has a suggestion of a tailstock setup that’s still under $100 USD. Continue reading “This $12 CNC Rotary Axis Will Make Your Head Spin” →

Mag Loop Antenna Has A Brain

April 11, 2023 by Al Williams 26 Comments

Magnetic loop antennas are great if you are limited on space since they are just a potentially small loop of wire. The problem is, they are sharply tuned. You normally have an adjustment capacitor to tune the antenna to different frequencies. [TekMakerUK] built one with a motor and an Arduino that he can tune from an Android phone. You can see more about the project in the video below.

If you want to transmit, the capacitor is often the weak part of the system. Luckily, some old gear yielded a capacitor with multiple sections and enough plate distance to handle the 5W desired. Of course, motor driving a capacitor isn’t a new idea, but this setup is nice since it uses a stepper motor and a rotary encoder.

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A white, house-shaped clock with the words "TEMPUS NECTIT" written in faux Roman script in black on a strip of silver at the base of the "roof." a white power cord extends from the left of the enclosure, and the center of the clock is a 22 pin knitting machine wheel with one pin covered in silver metalic. A white plastic peg extends from the bottom right of the enclosure to hold the feedstock yarn.

Tempus Nectit, A DIY Knitting Clock With Instructions

April 5, 2023 by Navarre Bartz 1 Comment

We’re no strangers to unusual clocks here at Hackaday, and some of our favorites make time a little more tangible like [Kyle Rankin]’s knitting clock.

Inspired by our coverage of [Siren Elise Wilhelmsen]’s knitting clock, [Rankin] decided to build one of his own. Since details on the build from the original artist were sparse, he had to reverse engineer how the device worked. He identified that a knitting clock is essentially a knitting machine with a stepper motor replacing the hand crank.

Using a Raspberry Pi with an Adafruit motor hat connected to a stepper motor and a 3D printed motor adapter, [Rankin] was able to drive the knitting machine to do a complete round of knitting every twelve hours. By marking one of the knitting pegs as an hour hand, the clock works as a traditional clock in addition to its year-long knitting task. [Rankin] says he still has some fine tuning to work on, but that he’s happy to have had the chance to combine so many of his interests into a single project.

If you’re looking for more knitting hacks, check out this knitted keyboard instrument or a knitted circuit board.

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Stepper Killer Killer Killed, Repair Attempted

March 8, 2023 by Chris Lott 12 Comments

The low-cost servo motor in [Clough42]’s lathe’s electronic leadscrew bit the dust recently, and he did a great job documenting his repair attempts ( see video below the break ). When starting the project a few years ago, he studied a variety of candidate motors, including a ClearPath servo motor from Teknic’s “Stepper Killer” family. While that motor was well suited, [Clough42] picked a significantly lower-cost servo motor from China which he dubbed the “Stepper Killer Killer”.

He does a very thorough post-mortem of the motor’s integrated servo controller, checking the circuits and connections on the interface PCB first. Not finding any obvious problem, he proceeds to the main PCB which contains the microcontroller, motor driver transistors, and power supplies. There is no visible damage, but a check of the logic power supply shows 1.65V where 3.3V is expected. Looking at the board with a smart-phone mounted IR camera, he quickly finds the bad news — the microcontroller has shorted out.

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3-DOF Robot Arm Wrist Without The Motor Weight

November 3, 2022 by Danie Conradie 15 Comments

A major challenge of robotic arms is the weight of the actuators, especially closer to the end of the arm. The long lever arm means more torque is required from the other actuators, and everything flexes a bit more. To get around this, [RoTechnic] moved the wrist stepper motors off the arms entirely.

He built a push-pull mechanism that uses braided fishing line to transfer motion to the robot arm’s wrist using Bowden tubes. The motors are mounted on the arm’s base, with a drum and two lengths of fishing line on the shafts. The lines pass through an adjustable tensioner before entering the Bowden tubes. This drum mechanism is also present on each of the three rotating axes of the wrist.

[RoTechnic] used an Arduino-powered RAMPS board as a controller, which is programmed to accept over the serial interface. He created a simple GUI and scripting interface in Jupyter Labs to generate and send command, which seems like an excellent solution for testing.

We can see this mechanism being a useful for a variety of motion applications, and definitely something to add to the idea toolbox. It is somewhat similar to some other cable-operated joints we’ve seen in humanoid robots and other 3D printed arms.

Continue reading “3-DOF Robot Arm Wrist Without The Motor Weight” →