A Pragmatic Guide To Motors With Jonathan Beri

[Jonathan Beri] is a Maker of all sorts, with an affinity for robots, APIs, and Open Source. By day he works on making Android & iOS SDKs easier to use and by night he can found begging a PID controller to “just work already.” Recently he contributed to, “Make: JavaScript Robotics,” printed by Maker Media (2015).

[Jonathan] covers a lot of ground during his motors talk at the 2015 Hackaday SuperConference. He discusses brushed DC, stepper, servo, and brushless motors. Although just scraping the surface of each type of motor [Jonathan] touches the important details you can use to determine which type of motor is best for your project. The slide show he has put together has quite a bit of information and tips for beginners that might go overlooked when choosing a motor. For instance a list of 30 attributes that should be considered when selecting a motor. Included in that list are the 7 attributes [Jonathan] places priority on when he chooses a motor for one of his projects. We’ll delve deeper into that after the break.

Continue reading “A Pragmatic Guide To Motors With Jonathan Beri”

Giant Stepper Motor Gets You Up To Speed On Theory

Few hackers have trouble understanding basic electric motors. We’ve all taken apart something that has a permanent magnet DC motor in it and hooked up its two leads to a battery to make it spin. Reverse the polarity, reverse the spin; remove the power, stop the spin. Stepper motors (and their close cousins, brushless DC motors) are a little tougher to grok, though, especially for the beginner. But with a giant 3D printed stepper motor, [Proto G] has made getting your head around electronically commutated motors a little easier.

While we’ve seen 3D printed stepper motors before, the size and simple layout of this one really lends to understanding the theory. With a 3D-printed frame, coils wound on nails, and rare-earth magnets glued to a rotor, this is an approachable build that lays the internals of a stepper motor out for all to see and understand. You can easily watch how the rotor lines up as the various coils are energized in a circular pattern, although it might be more revealing to include bi-color LEDs to indicate which coils are energized and what the polarity is. Those would be especially helpful demonstrating the concept of half-stepping. We’d also like to see more detail on the controller electronics, although admittedly all the video-worthy action is in the motor itself.

Continue reading “Giant Stepper Motor Gets You Up To Speed On Theory”

Robot On Rails For Time Lapse Photography

What do you get when you cross a photographer with an Arduino hacker? If the cross in question is [nukevoid], you wind up with a clever camera rail that can smoothly move with both shift and rotation capability. The impressive build uses an Arduino Pro Mini board and two stepper motors. One stepper moves the device on rails using some Delrin pulleys as wheels that roll on an extruded aluminum track. The other stepper rotates the camera platform.

The rotating platform is very cool. It’s a plastic disk with a GT2 motion belt affixed to the edge. The stepper motor has a matching pulley and can rotate the platform easily. The GT2 belt only goes around half of the disk, and presumably the software knows when to stop on either edge based on step counts. There’s even a support to steady the camera’s lens when in operation.

Continue reading “Robot On Rails For Time Lapse Photography”

Hackaday Prize Entry: Orchestral Invention Defies Convention

Like many of us, [Laurens] likes video game music and bending hardware to his will. Armed with a Printrbot, a couple of floppy drives, and some old HDDs, he built the Unconventional Instrument Orchestra. This 2015 Hackaday Prize contender takes any MIDI file and plays it on stepper and solenoid-based hardware through a Java program.

A while back, [Laurens] won a Fubarino in our contest by using a MIDI keyboard and an Arduino to control the Minecraft environment with Legend of Zelda: Ocarina of Time songs. The Unconventional Instrument Orchestra uses that Fubarino of victory to control the steppers of two floppy drives. He only needed three pins to control the drives—one to enable, one to set the head’s direction, and one to make it step once per pulse.

If ever you’ve been around a 3D printer, you know they make music as a natural side effect. The problem is getting the printer to obey the rests in a piece of music. In order to do this, [Laurens] used his software to control the printer, essentially withholding the next command until the appropriate time in the song.

The percussive elements of this orchestra are provided by a hard drive beating its head against the wall. Since it’s basically impossible to get an HDD to do this as designed (thankfully), [Laurens] replaced the control board with a single transistor to drive the coil that moves the head.

[Laurens] has made several videos of the orchestra in concert, which are a joy all their own. Most of the visual real estate of each video is taken up with a real-time visualization of the music produced by the software. There’s still plenty of room to show the orchestra itself, song-specific gameplay, and a textual commentary crawl in 16-segment displays. Check out the playlist we’ve embedded after the break.

The 2015 Hackaday Prize is sponsored by:

Continue reading “Hackaday Prize Entry: Orchestral Invention Defies Convention”

Rotary Indexer Gives Mill A 4th Axis (sort Of)

Rotary indexer’s are standard issue in most machine shops. These allow you to hold or chuck a work piece, and then a graduated handle lets you to rotate the workpiece. Useful when you want to drill or tap axial or radial features. A rack and pinion drive ensures that the workpiece does not move under machining load. Quite often, these indexers also have a manual lock to take care of gear backlash and play. Automating them is not too difficult either. You could use just a stepper motor (open loop) or servo+encoder (closed loop) to drive the turntable.

[smashedagainst] needed to drill six radial holes on a part. And he had to do it on 500 pieces for a total of 3000 holes. That was just for the first initial run, with more drilling likely in the future. The part in question was small and light weight. So instead of using a heavy duty, industrial grade unit, he built an all-electric rotary indexing jig using a stepper motor and an Arduino, giving him a sort of rotary 4th axis. His idea was to directly use the stepper motor to rotate the workpiece without any gearing, but he needed to build his own rig to do so.

Continue reading “Rotary Indexer Gives Mill A 4th Axis (sort Of)”

Pump Up The Volume With The 3D Printed Syringe Pump Rack

Syringe pumps are valuable tools when specific amounts of fluid must be dispensed at certain rates and volumes. They are used in many ways, for administering IV medications to liquid chromatography (LC/HPLC). Unfortunately, a commercial pump can cost a pretty penny. Not particularly thrilled with the hefty price tag, [Aldric Negrier] rolled up his sleeves and made a 3D-printed version for 300 USD.

[Aldric] has been featured on Hackaday before, so we knew his latest project would not disappoint. His 3D Printed Syringe Pump Rack contains five individual pumps that can operate independently of each other. Five pieces are 3D-printed to form the housing for each pump. In addition, each pump is composed of a Teflon-coated lead screw, an Arduino Nano V3, a Pololu Micro stepper motor driver, and a NEMA-17 stepper motor. The 3D Printed Syringe Pump Rack runs on a 12V power supply using a maximum of 2 amps per motor.

While the standard Arduino IDE contains the Stepper library, [Aldric] wanted a library that allowed for more precise control and went with the Accelstepper library. The 3D Printed Syringe Pump Rack has a measured accuracy of 0.5µl in a 10ml syringe, which is nothing to laugh at.

Syringe pump racks like [Aldric’s] are another great example of using open source resources and the spirit of DIY to make typically expensive technologies more affordable to the smaller lab bench. If you are interested in other open source syringe pump designs, you can check out this entry for the 2014 Hackaday Prize.

Continue reading “Pump Up The Volume With The 3D Printed Syringe Pump Rack”

A Recycled Robot Arm For All!

It’s mind boggling how much e-waste we throw out. Perfectly good components, mass produced for pennies. And at the end of their life, going straight to a landfill or some poor country to be melted down. Don’t you wish you could help?

Stepper motors are a dime a dozen when it comes to e-waste, and there’s tons of cool projects you can do with a stepper motor — [Madivak] is just starting on a robot arm design over at Hackaday.io that makes use of recycled components.

It’s fairly early in development, but that means it’s a great time to start following it on the project site. The robotic arm is being designed for his final year project in his undergrad degree. Besides the steppers, he’s using his school’s Utilimaker 3D printer to manufacture all of the other mechanical components with control coming from DRV8825 stepper drivers and the Freescale Freedom KL25Z dev kit. Check out the clips after the break to see current state of the build.

Continue reading “A Recycled Robot Arm For All!”