When [bdk6] tried painting aluminum for electronic projects, he found it didn’t tend to stay painted. It would easily scratch off or, eventually, even flake off. The problem is the paint doesn’t want to adhere to the aluminum oxide coating around the metal. Research ensued, and he found an article in an old ham radio magazine about a technique that he could adapt to get good results painting aluminum.
Actually, paint apparently adheres poorly, even to non-oxidized aluminum. So the plan is to clean and remove as much aluminum oxide as possible. Then the process will convert the aluminum surface to something the paint sticks to better. Of course, you also need the right kind of paint.
The key ingredients are phosphoric acid and zinc phosphate. Phosphoric acid is found in soft drinks, but is also sold as a concrete and metal prep for painting. The zinc phosphate is part of a special paint known as a self-etching primer.
Cleaning takes soap, elbow grease, and sandpaper. The next step is a long soak in the phosphoric acid. Then you apply a few coats of self-etching primer and sand. Once it is all set, you can paint with your normal paint. That’s usually epoxy-based paint for [bdk6].
As you might expect, the release of last year’s Ghostbusters: Afterlife has not only lead to renewed interest in the old 1980s toys and tie-in merchandise, but has spawned a whole new generation of blinking plastic gadgets to delight children of all ages. Of course, for folks like us, that means more hardware to hack on.
In a recent post to the official Ghostbusters YouTube channel, professional prop maker [Ben Eadie] shows off some of the tricks of the trade when he takes a $15 USD “PKE Meter” toy from Hasbro and turns it into a screen-quality prop. Even if you’re not looking to get an early start on your Halloween costume, the techniques demonstrated in this video could be easily adapted to other projects. For those whose next ideal home improvement is a fireman’s pole and an ectoplasmic laser-confinement grid, you might want to grab a couple of these toys while they’re still cheap for eventual conversion.
Uncovering the silver makes the piece look worn down.
The biggest takeaway from the video is probably the finishing techniques, as they could be used on any sort of realistic prop build. [Ben] starts by using a cabinet scraper to smooth out the lines on the plastic toy, and any holes are filled with the familiar baking soda and cyanoacrylate glue trick. Once the surfaces have been prepped, all the principle parts are sprayed with an adhesion promoter, followed by a coat of silver, and then the final black color.
This allows him to create a convincing “chipped paint” effect by strategically sanding or scraping through the top coat. Dabbing some toothpaste where you want the device to look worn down before spraying the final coat makes the process even faster, as it will prevent the top coat from sticking to the silver in the first place.
Unfortunately [Ben] doesn’t spend a whole lot of time explaining the electronics side of things, but it doesn’t look like there’s anything too complex going on. All the original gear is stripped, and it gets replaced with a microcontroller which we believe is an Adafruit ItsyBitsy nRF52840 Express. This is connected to two strings of tiny APA102 addressable LEDs which are run down the “wings” (we especially like the 3D printed lenses used to replace the original solid pips), and one that’s used to provide the iconic sine-wave display.
When putting together a home workshop, available floor space is often the deciding factor when it comes time to pick tools and equipment. This ultimately leads to some very difficult decisions, and we’d wager there isn’t a hacker or maker reading this that hasn’t had to pass on a new piece of gear because they didn’t have anywhere to put it.
For example, the average home gamer isn’t going to have a paint booth and spraying equipment, so they have to settle for a rattle can in the backyard. Traditionally this has limited the kinds of products you can realistically apply, but as [Eric Strebel] shows off in his latest video, it seems like spray can technology is starting to catch up.
The finish after two coats of primer.
Specifically, he’s been working with a canned two-part primer that doesn’t require any complicated mixing or special equipment to apply. After hitting a plunger on the bottom, a small compartment containing the activator is ruptured and the reaction begins. From that point, you’ve only got 24 hours to use the contents of the can before it cures. But since you only need to wait about 10 minutes between coats, that should give you plenty of time to complete the project.
In the video, [Eric] demonstrates how quickly this high-build primer can smooth out the layer lines on a 3D print. While you’ll still need to sand and potentially break out the spot filler to achieve that perfect finish, it’s clear that the primer works much better than anything we’re used to seeing come out of a can. Even after just two coats, the results are truly remarkable.
If there’s a downside, it’s that a can of this primer will run you about $25 USD. That’s about five times the cost of the Rust-Oleum Filler Primer that usually gets recommended in DIY circles, but the results really do seem to speak for themselves. We wouldn’t necessarily use this on every project, but if you’ve got something that needs an especially fine finish, you’ve at least got an option that doesn’t involve borrowing somebody’s compressor and spray gun.
If you need help shaking your paint before spraying – definitely give this 3D printed paint shaker a look!
Creativity is a very human trait, and one that many try to emulate with robots. Some focus on the cerebral side of things, working with neural networks and machine learning to produce new artistic output. Others work on the mechanical side, building ‘bots that can manipulate tools in the real world for artistic purposes. [Technovation]’s latest build falls into the latter category – a small Arduino-powered ‘bot that likes to paint.
The robot moves around on two wheels, each driven by a stepper motor for accurate movement. The paintbrush itself is controlled with another stepper, which rotates it between the paint pots and the canvas. A servo is used to dip the brush into pots, and to apply it to the canvas. An Arduino Uno runs the show, with the robot currently programmed to paint random lines of various colors on the canvas.
By virtue of its roving design, it could theoretically paint on arbitrarily large canvasses. It’s a platform that could prove highly capable when paired with a neural network and perhaps some machine vision to allow it to concoct more complex artworks. We’ve seen other paint bots before, too. Video after the break.
Let’s say you’ve watched a few episodes of “The Joy of Painting” and you want your inner [Bob Ross] to break free. You get the requisite supplies for oil painting – don’t forget the alizarin crimson! – and start to apply paint to canvas, only to find your happy little trees are not so happy, and this whole painting thing is harder than it looks.
[Saint Bob] would certainly encourage you to stick with it, but if you have not the patience, a CNC painting robot might be a thing to build. The idea behind [John Opsahl]’s “If Then Paint” is not so much to be creative, but to replicate digital images in paint. Currently in the proof-of-concept phase, If Then Paint appears to have two main components: the paint management system, with syringe pumps to squeeze out different paints to achieve just the right color, and the applicator itself, a formidable six-axis device that supports tool changes by using different brushes chucked up into separate hand drill chucks. The extra axes at the head will allow control of how the brush is presented to the canvas, and also allow for cleaning the brush between colors. The videos below show two of the many ways [John] is exploring to clean the brushes, but sadly neither is as exciting as the correct [Bob Ross] method.
It looks like If Then Paint has a ways to go yet, but we’re impressed by some of the painting it has produced already. This is just the kind of project we like to see in the 2019 Hackaday Prize – thought out, great documentation, and a lot of fun.
I print something nearly every day, and over the last few years, I’ve created hundreds of practical items. Parts to repair my car, specialized tools, scientific instruments, the list goes on and on. It’s very difficult for me to imagine going back to a time where I didn’t have the ability to rapidly create and replicate physical objects at home. I can say with complete honesty that it has been an absolutely life-changing technology for me, personally.
But to everyone else in my life, my friends and family, 3D printers are magical boxes which can produce gadgets, weapons, and characters from their favorite games and movies. Nobody wants to see the parts I made to get my girlfriend’s 1980’s Honda back on the road before she had to go to work in the morning, they want to see the Minecraft block I made for my daughter. I can’t get anyone interested in a device I made to detect the algal density of a sample of water, but they all want me to run off a set of the stones from The Fifth Element for them.
As I recently finished just such a project, a 3D printed limpet mine from Battlefield 1, I thought I would share some thoughts on the best practices for turning fiction into non-fiction.
Telling somebody that you’re going to make their dreams come true is a bold, and potentially kind of creepy, claim. But it’s one of those things that isn’t supposed to be taken literally; it doesn’t mean that you’re actually going to peer into their memories, extract an idea, and then manifest it into reality. That’s just crazy talk, it’s a figure of speech.
Original sketch of the CURV II
As it turns out, there’s at least one person out there who didn’t get the memo. Remembering how his father always told him about the elaborate drawings of submarines and rockets he did as a young boy, [Ronald] decided to 3D print a model of one of them as a gift. Securing his father’s old sketchpad, he paged through until he found a particularly well-developed idea of a personal sub called the CURV II.
The final result looks so incredible that we hear rumors manly tears may have been shed at the unveiling. As a general rule you should avoid making your parents cry, but if you’re going to do it, you might as well do it in style.
Considering that his father was coming up with detailed schematics for submarines in his pre-teen days, it’s probably no surprise [Ronald] has turned out to be a rather accomplished maker himself. He took the original designs and started working on a slightly more refined version of the CURV II in SolidWorks. Not only did he create a faithful re-imagining of his father’s design, he even went as far as adding an interior as well as functional details such as the rear hatch. Continue reading “3D Printing Brings A Child’s Imagination To Life”→
