Vastly Improved Servo Control, Now Without Motor Surgery

March 21, 2024 by 13 Comments

Hobby servos are great, but they’re in many ways not ideal for robotic applications. The good news is that [Adam] brings the latest version of his ServoProject, providing off-the-shelf servos with industrial-type motion control to allow for much, much tighter motion tracking than one would otherwise be limited to.

Modifying a servo no longer requires opening the DC motor within.

The PID control system in a typical hobby servo is very good at two things: moving to a new position quickly, and holding that position. This system is not very good at smooth motion, which is desirable in robotics along with more precise motion tracking.

[Adam] has been working on replacing the PID control with a more capable cascade-based control scheme, which can even compensate for gearbox backlash by virtue of monitoring the output shaft and motor position separately. What’s really new in this latest version is that there is no longer any need to perform surgery on the DC motor when retrofitting a servo; the necessary sensing is now done externally. Check out the build instructions for details.

The video (embedded just below) briefly shows how a modified servo can perform compared to a stock one, and gives a good look at the modifications involved. There’s still careful assembly needed, but unlike the previous version there is no longer any need to actually open up and modify the DC motor, which is a great step forward.

Continue reading “Vastly Improved Servo Control, Now Without Motor Surgery” →

Ask Hackaday: What About Imperfect Features?

January 24, 2024 by 24 Comments

Throughout the last few years’ time, I’ve been seeing sparks of an eternal discussion here and there. It’s a nuanced one, but if I could summarize, it’s about different feature development strategies we can follow to design things, especially if they’re aimed at a larger market. Specifically – when adding a feature, how complete and perfect should it be?

A while back, I read a Mastodon thread about VLC not implementing backwards per-frame skipping. At the surface level, it’s about an indignant user asking – what’s the deal with VLC not having a “go back a frame” button? A ton of video players have this feature implemented. There’s a forum thread linked, and, reading it could leave you with a good few conflicting emotions. Here’s a recap.

In what appears to be one of multiple threads asking about a ‘previous frame’ button in VLC, there’s an 82-post discussion involving multiple different VLC developers. The users’ argument is that it appears to be clearly technically possible to add a ‘previous frame’ button in practice, and the developers’ argument is that it’s technologically complex to implement in some cases – for certain formats, even impossible to implement! Let’s go into the developers’ stated reasoning in more details, then – here’s what you can find in the thread, to the best of my ability.

Continue reading “Ask Hackaday: What About Imperfect Features?” →

CNC Plus Microscope Plus Game Controller Equals Awesome

November 20, 2023 by 4 Comments

What do you get if you strap a microscope onto a CNC and throw in a gaming controller? The answer, according to Reddit user [AskewedBox] is something kind of awesome: you get a microscope that can be controlled with the game controller for easier tracking of tiny creepy-crawlies.

[ASkewedBox] set up this interesting combination of devices, attaching their Adonostar AD246S microscope to the stage of a no-brand 1610 CNC bought off Amazon, then connected the CNC to a computer running Universal G-Code Sender. This great open source program takes the input from an Xbox game controller and uses it to jog the CNC.

With a bit of tweaking, the game controller can now move the microscope, so it can be used to track microbes and other small creatures as they wander around on the slide mounted below the microscope eating each other. The movement of this is surprisingly smooth: the small CNC and a well-mounted microscope means that there seems to be very little wobble or backlash as the microscope moves.

[Askewedbox] hasn’t finished yet, though: in the latest update, he adds a polarizing lens to the setup and mentions that he wants to add focus control to the system, which is controlled by a remote that comes with the microscope.

There are plenty of other things that could be added beyond that, though, such as auto pan and stitch for larger photos, auto focus stacking and perhaps even auto tracking using OpenCV to track the hideous tiny creatures that live in the microscopic realm. What would you do to make this even cooler?

Most AI Content Is Trash, Just Like Everything Else

November 3, 2023 by 31 Comments

[Max Woolf] has been working in the AI space since 2015, and among other work has created numerous useful open-source tools. He also recently wrote a thoughtful blog post that attempts to put into words his feelings on the state of things in the wake of experiencing a bit of an AI backlash-related burnout. Essentially, people effortlessly creating vast amounts of bad AI content has caused a bigger problem than we may realize.

How so? Well, Sturgeon’s law (summarized as “ninety percent of everything is crud”) applies to AI as much as it does to anything else. Theodore Sturgeon was a science fiction author and critic (and writer of multiple Star Trek episodes) who observed in the 1950s that while Science Fiction — the hot new popular thing at the time — was often derided by critics as being little more than low quality pap, so was everything else. It was true that most Science Fiction was garbage. But most work in other fields was of similarly low quality, and thus Science Fiction was really no different. It’s all trash, except for the parts one likes. Just like anything else.

What makes this observation particularly applicable to the current AI landscape is that, according to [Max], the incredible ease of use makes AI’s “ninety percent crud” very large indeed, and the attached backlash is similarly big. The remaining ten percent of AI that is absolutely fantastic and full of possibilities? It’s practically invisible due to how quickly the industry is moving, the speed with which the big players are vying to control it, and how unfashionable it has become to admit one is using AI tools at all.

[Max] knows the scene better than most. One of his projects is simpleaichat, a tool aimed not just at enabling people to integrate AI into projects easier, but piercing the hype around AI to more easily reveal just how these tools actually work. Sadly, a general AI backlash has made developing these tools feel rather less rewarding than it once did.

Labor Day BBQs May Feature NYPD

September 1, 2023 by 53 Comments

Planning to host a large backyard wingding in the NYC metro area this weekend? Be sure to watch the skies for uninvited guests. That’s right, the NYPD are deploying drones over “large” Labor Day events and yes, even private barbecues. The strategy was announced during a briefing about J’ouvert — that’s a yearly Caribbean festival that marks the end of slavery. It generally brings crowds of thousands and draws a strong police presence to Brooklyn.

While this particular invasion may come as a bit of a shock, this certainly isn’t the first time the NYPD has deployed drones in the name of public safety or in response to emergencies. Data shows they have used them 124 times this year, which is up a staggering 31 times from the four events in 2022.

As you may have guessed, this has invited backlash from privacy and civil liberties advocates. One pointed out that this action “flies in the face of the POST Act,” a city law that requires the NYPD to provide transparency about their various surveillance tactics. The advocates cite the fact that regulations have not kept up with the proliferation of technology.

No matter what happens in the future with regulations, the NYPD can always crash large parties the old fashioned way. Usually, the neighbors will complain at some point, unless they were all invited.

Photo via Unsplash.

Rocky Strikes Back At Red Hat

June 30, 2023 by 56 Comments

The world of Linux has seen some disquiet over recent weeks following the decision of Red Hat to restrict source code distribution for Red Hat Enterprise Linux (RHEL) to only their paying customers. We’re sure that there will be plenty of fall-out to come from this news, but what can be done if your project relies upon access to those Red Hat sources?

The Red-Hat-derived Rocky Linux distro relies on access to RHEL source, so the news could have been something of a disaster. Fortunately for Rocky users though, they appear to have found a reliable way to bypass the restriction and retain access to those RHEL sources. Red Hat would like anyone wanting source access to pay them handsomely for the privilege, but the Rocky folks have spotted a way to bypass this. Using readily available cloud images they can spin up a RHEL system and use it to download their sources, and they can do this as an automated process.

We covered this story as it unfolded last week, and it seemed inevitable then that something of this nature would be found, as for all Red Hat’s wishes a GPL-licensed piece of code can’t be prevented from being shared. So Rocky users and the wider community will for now retain access to the code, but will Red Hat strike back? It’s inevitable that there will be a further backlash from the community against any such moves, but will Red Hat be foolhardy enough to further damage their standing in this regard? They’re certainly not the only large distro losing touch with their users.

Spindle Upgrade Makes PocketNC Faster And Smoother

June 27, 2023 by 21 Comments

Conventional wisdom says that rigidity is the name of the game when it comes to machine tool performance. After all, there’s got to be a reason for CNC machines that need specialized rigging companies just to deliver them. But is there perhaps a way for the hobby machinist to cheat a little on that?

From the look of [Ryan]’s PocketNC spindle upgrade, it seems like the answer just might be yes. The PocketNC, a much-coveted five-axis CNC mill sized for the home shop, has a lot going for it, but as with most things, there are trade-offs. Chief among these is a lack of the usual huge, heavy castings used for CNC machines, which results in the tendency for the cutting tool to chatter or even stall out if you push the speeds and feeds too far. After a good intro to some of the important metrics of machining, such as “material removal rate,” the video below delves into how MRR affects chip load which in turn results in chatter.

The easy fix for chatter, of course, is to take smaller cuts. But [Ryan] decided to increase the spindle speed to take lighter cuts, but to do it really fast. The hardware for this includes a 3,500 KV high-torque brushless DC motor and a custom spindle attachment. The motor is connected to the spindle shaft using pulleys and a drive belt, and the shaft is supported with stout bearings that can be pre-loaded to fight backlash. The end result is three times the stock 10,000 RPM spindle speed, which lets [Ryan] see a 300% increase in cycle time on his PocketNC. And as a bonus, the whole thing requires no permanent modification to the machine and can be easily removed.

We think [Ryan] did a great job breaking this problem down to the essentials and hacking up a low-cost solution to the problem. Continue reading “Spindle Upgrade Makes PocketNC Faster And Smoother” →