Compact Driver Powers Steppers With USB-C PD

August 24, 2024 by Dan Maloney 12 Comments

NEMA-17 steppers are (almost) a dime a dozen. They’re everywhere, they’re well-known to hackers and makers, and yet they’re still a bit hard to integrate into projects. That’s because the motor alone isn’t much use, and by the time you find or build a driver and integrate it with a microcontroller, you’ve probably expended more effort than you will on the rest of the project. This USB-C PD stepper driver aims to change that.

What caught our eye about [Josh Rogan]’s PD Stepper is his effort to make this a product rather than just a project. The driver is based on a TMC2209 for silent operation and a lot of torque thanks to the power delivery capabilities of USB-C PD. The PCB is very nicely designed and has an AS5600 rotary magnetic encoder for closed-loop operation. There’s also an ESP32-S3 on-board, so WiFi and Bluetooth operation are possible — perfect for integration into Home Assistant via ESPHome.

[Josh]’s mechanical design is top-notch, too, with a machined aluminum spacer that fits on the back of a NEMA-17 motor perfectly and acts as a heat spreader. A machined polycarbonate cover protects the PCB and makes a very neat presentation. [Josh] has kits available, or you can roll your own with the provided build files.

Continue reading “Compact Driver Powers Steppers With USB-C PD” →

Arduino Sticker Dispenser Saves Time

November 12, 2023 by Kristina Panos 18 Comments

What’s the worst part about packaging up a whole lot of the same basic thing? It might just be applying the various warning stickers to the outside of the shipping box. Luckily, [Mr Innovative] has built an open-source automatic sticker dispenser that does the peeling for you, while advancing the roll one at a time quite satisfyingly.

This tidy build is made primarily of 20×20 extruded aluminium and stainless steel smooth rod. All the yellow bits are 3D printed. The brains of this operation is an Arduino Nano, with an A4988 stepper motor driver controlling a NEMA17.

Our favorite part of this build is the IR sensor pair arranged below the ready sticker. It detects when a sticker is removed, then the stepper advances the roll by one sticker height. The waste is collected on a spool underneath.

Between the video and the instructions, [Mr Innovative] has made it quite simple to build one for yourself. Definitely check this one out after the break.

[Mr Innovative] may as well go by [Mr. Automation]. Check out this automated wire prep machine from a few years ago.

Continue reading “Arduino Sticker Dispenser Saves Time” →

A DIY Equatorial Mount Using Harmonic Drives

November 10, 2022 by Dave Rowntree 28 Comments

As an amateur astrophotographer will tell you, you just don’t get to capture the really interesting objects without spending a ton of money on some decent pieces of kit. Telescope aside, there really is a surprising amount of complexity, weight, and associated costs with the telescope mount alone, let alone one that is capable of any sort of programmable tracking. [Alan (Jialiang) Zhao] clearly wanted to up their game, and having suffered some of the shortcomings of their Sky-Watcher HEQ-5 pro Equatorial mount decided to go ahead and build an open-source mount, Alkaid, which hopefully works a bit better for them.

In simple terms, the difficulty of photographing an extremely dim, distant object (or one that is larger but diffuse) is that the camera sensor needs to spend a significant amount of time signal-averaging, to gather enough light for anything to be seen at all, through the noise. But, this ball of rock we sit on is rotating constantly, so the only solution is to track the object of interest, to compensate. This is referred to as equatorial tracking, and allows the rotation of the Earth to be compensated for during a long exposure.

The design of each of the two axes revolves (sorry!) around the use of a NEMA-17 stepper motor with a 27:1 planetary gearbox, driving into a harmonic reducer gearbox. Harmonic drives (aka strain wave drives) are pretty neat, working on the principle of a fixed, but circularly distorting ring gear that transmits torque from the inside surface to the outside, with almost no backlash. They are expensive parts, but for a super smooth movement, this is what you want. The huge output torque they allow, meant that [Alan] was able to build a mount for a heavy telescope without any counterbalances. Structurally, the whole thing is constructed from 10 mm thick aluminium plates that were cut with a waterjet and subsequently milled to finish. Continue reading “A DIY Equatorial Mount Using Harmonic Drives” →

You Need An Automated Overhead Camera Assistant

April 14, 2021 by Kristina Panos 13 Comments

It’s 2021. Everyone and their mother is filming themselves doing stuff, and a lot of it is super cool content. But since most of us have to also work the video capture devices ourselves, it can be difficult to make compelling footage with a single, stationary overhead view, especially when there are a lot of steps involved. A slider rig is a good start, but the ability to move the camera in three dimensions programmatically is really where it’s at.

[KronBjorn]’s excellent automated overhead camera assistant runs on an Arduino Mega and is operated by typing commands in the serial monitor. It can pan ±20° from straight down and moves in three axes on NEMA-17 stepper motors. It moves really smoothly, which you can see in the videos after the break. The plastic-minimal design is interesting and reminds us a bit of an ~~ophthalmoscope~~ phoropter — that’s that main rig at the eye doctor. There’s only one thing that would make this better, and that’s a dedicated macro pad.

If you want to build your own, you’re in luck — there’s quite a lot of detail to this project, including a complete BOM, all the STLs, code, and even assembly videos of the 3D-printed parts and the electronics. Slide past the break to check out a couple of brief demo videos.

Not enough room for a setup like this one? Try the pantograph version.

Continue reading “You Need An Automated Overhead Camera Assistant” →

An Automatic Label Dispenser For Quicker Stickers

October 28, 2020 by Kristina Panos 10 Comments

If you have any kind of business, chances are it involves stickers at some point in the process. More accurately it involves you peeling the backs off of sticker after sticker, slowly wasting time and working your way toward a repetitive stress injury. Why do that to yourself when you could have a machine do it for you?

That’s exactly the thinking behind [Mr Innovative]’s automatic label dispensing machine. All he has to do is load up the roll of labels, dial in the length of each label, and away the machine goes, advancing and dispensing and taking up the empty paper all at once. In fact, that’s how it works: the take-up reel is on the shaft of a NEMA-17 stepper motor, which gets its instructions from an Arduino Nano and an A4988 motor driver. Our favorite part is the IR sensor located underneath the sticker that’s ready to take — the machine doesn’t feed another until it senses that you’ve taken the previous sticker. We stuck the demo and build video after the break.

Our other favorite thing about this build is that [Mr Innovative] seems to have used the same PCB as his freaky fast bobbin winder.

Continue reading “An Automatic Label Dispenser For Quicker Stickers” →

Arduino Bobbin Winding Machine Is Freaky Fast

October 20, 2020 by Kristina Panos 16 Comments

One of the worst things about sewing is finding out that your bobbin — that’s the smaller spool that works together with the needle and the larger spool to make a complete stitch — ran out of thread several stitches ago. If you’re lucky, the machine has a viewing window on the bobbin so you can easily tell when it’s getting dangerously close to running out, but many machines (ours included) must be taken halfway apart and the bobbin removed before it can be checked.

Having spare bobbins ready to go is definitely the answer. We would venture to guess that most (if not all) machines have a built-in bobbin winder, but using them involves de-threading the machine and setting it up to wind bobbins instead of sew. If you have a whole lot of sewing to do and can afford it, an automatic bobbin winder is a godsend. If you’re [Mr. Innovative], you build one yourself out of acrylic, aluminium, and Arduinos.

Here’s how it works: load up the clever little acrylic slide with up to twelve empty bobbins, then dial in the speed percentage and press the start button. The bobbins load one at a time onto a drill chuck that’s on the output shaft of a beefy 775 DC motor. The motor spins ridiculously fast, loading up the bobbin in a few seconds. Then the bobbin falls down a ramp and into a rack, and the thread is severed by a piece of nichrome wire.

An important part of winding bobbins is making sure the thread stays in place at the start of the wind. We love the way [Mr. Innovative] handled this part of the problem — a little foam doughnut around a bearing holds the thread in place just long enough to get the winding started. The schematic, BOM, and CAD files are available if you’d like to make one of these amazing machines for yourself. In the meantime, check out the demo/build video after the break.

Still not convinced that sewing is cool enough to learn? Our own [Jenny List] may be able to convert you. If that doesn’t get you, you might like to know that some sewing machines are hackable — this old girl has a second life as a computerized embroidery machine. If those don’t do it, consider that sewing machines can give you a second life, too.

Continue reading “Arduino Bobbin Winding Machine Is Freaky Fast” →

Finally, A Differently Useless Machine

September 20, 2020 by Kristina Panos 32 Comments

Traditionally, the useless machine is a simple one that invites passersby to switch it on. When they do, the machine somehow, some way, turns itself off; usually with a finger or finger-like object that comes out from the box in what feels like an annoyed fashion. Honestly, that’s probably part of what drives people to turn them on over and over again.

But [Bart Blankendaal] has managed to turn the useless machine on its head. When this machine is switched to the on position, unseen forces inside the box will spin the toggle switch around 180° to the off position.

What’s really happening is that an Arduino is getting a signal from the toggle switch, and is then rotating it on a ball bearing with a stepper motor driven through an H-bridge.

It shouldn’t be too hard to make one of these yourself, given that [Bart] has provided the schematic and STLs. If we weren’t living in such touchy times, we might suggest building one of these into your Halloween candy distribution scheme somehow. Sell the switch as one that turns on a candy dispenser, and then actually dispense it after three or five tries.

Many see useless machines as tangible examples of existential quandary. Here is one that takes that sentiment a bit further by snuffing out a candle.

Continue reading “Finally, A Differently Useless Machine” →