[Oscar] wonders why hobby projects ignore all the powerful brushless motors available for far less than the equivalent stepper motors, especially with advanced techniques available to overcome their deficiencies. He decided it must be because there is simply not a good, cheap, open source motor controller out there to drive them precisely. So, he made one.
Stepper motors are good for what they do, open-loop positioning along a grid, but as far as industrial motors go they’re really not the best technology available. Steppers win on the cost curve for being uncomplicated to manufacture and easy to control, but when it comes to higher-end automation it’s servo control all the way. The motors are more powerful and the closed-loop control can be more precise, but they require more control logic. [Oscar]’s board is designed to fill in this gap and take full advantage of this motor control technology.
The board can do some pretty impressive things for something with a price goal under $50 US dollars. It supports two motors at 24 volts with up to 150 amps peak current. It can take an encoder input for full closed loop control. It supports battery regeneration for braking. You can even augment a more modest power supply to allow for the occasional 1 KW peak movement with the addition of a lithium battery. You can see the board showing off some of its features in the video after the break.
We love good pictures. You know, being worth a thousand words and all. So, after our article on taking good reference photos, we were pleased to see a reader, [Steve], sharing his photography set-up.
Taking good technical photos is a whole separate art from other fields of photography like portraiture. For example, [Steve] mentions that he uses “bullseye” composition, or, putting the thing right in the middle. The standard philosophy on this method is that it’s bad and you are bad. For technical photos, it’s perfect.
[Steve] also has some unique toys in his arsenal. Like a toy macro lens from a subscription chemistry kit. He also showed off his foldscope. Sadly, they appear to no longer be for sale, but we sometimes get by with a loupe held in front of the lens. He also uses things standard in our shop. Such as a gridded cutting mat as a backdrop and a cheap three dollar tripod with spring actuated jaws to hold his phone steady.
In the end, [Steve] mostly shows that a little thought goes a long way to producing a photo that doesn’t just show, but communicates an idea in a better way than just words can manage.
[Mr. Name Required] pointed us to a great video on the modeling of a replica Apple /// to the small scale needed to contain a Raspberry Pi by [Charles Mangin].
[Mr. Name] pointed out that the video was a great example of the use of reference photos for modeling. [Charles] starts by finding the references he needs for the model. Google image search and some Apple history websites supplied him with the required images.
He modeled the Apple /// in Autodesk 123. It has sketch tools, but he chose to craft the paths in iDraw and import them into the software. This is most likely due to the better support for boolean combination tools in vector editing software. Otherwise he’d have to spend hours messing with the trim tool.
Later in the video he shows how to change the perspective in photographs to get a more orthographic view of an object. Then it’s time for some heavy modeling. He really pushes 123 to its limit.
The model is sent off for professional 3D printing to capture all the detail. Then it’s some finishing work and his miniature Apple /// is done. Video after the break.
Have you ever wanted to own a full-sized ShopBot? What if some geniuses somewhere made a tool the size of a coffee maker that had the same capabilities? Does an augmented reality, real-time feedback, interactive, handheld CNC router that can make objects ranging in size from a pillbox to an entire conference room table sound like a thing that even exists? It didn’t to me at first, but then I visited the Shaper Tools office in San Francisco and they blew my mind with their flagship tool, Shaper Origin.
It’s impossible for me not to sound like a fan boy. Using Shaper Origin was one of those experiences where you just don’t know what to say afterwards. This is what the future looks like.
I’ve used a lot of CNC tools in my life, from my first home-built CNC conversion, to 1980s monstrosities that ran off the floppy kind of floppy disks, and all the way over to brand new state-of-the-art vertical machining centers. I had to shake a lot of that knowledge off when they demoed the device to me.
Origin is a CNC router built into the form factor of a normal wood router. The router knows where it is on the work piece. You tell it where on the piece you would like to cut out a shape, drill a hole, or make a pocket. It tells you where to go, but as you move it keeps the cutting bit precisely on the path with its three axes of control.
[S.PiC] has been working on a computer case styled to look like the Vulture mech from Battletech. We’re not sure if his serious faced cat approves or not, but we do.
The case is made from artfully cut plywood. We kind of hope he keeps the wood aesthetic. However, that would be getting dangerously close to steampunk. So perhaps a matching paint job at the end will do. In some of the videos we can how he’s cleverly incorporated the computer’s components into the design of the case. For example, the black mesh on the front actually hides the computer’s power supply intake fan.
The computer inside is a small micro-itx formfactor one. Added as peripherals to it [S.Pic] has pulled out the hacker-electronics-tricks bible. From hand soldered LED grids to repurposed Nokia LCD screens, he has it all. In one video we can even see the turret of the mech rotating under its own power.
It looks like the build still has a few more steps before completion, but it’s already impressive enough to be gladly worth the useful table space consumed on any hacker’s desk. Video after the break.
Many productive hackers bleed a dark ochre. The prevailing theory among a certain group of commenters is that they’re full of it, but it’s actually a healthy sign of a low blood content in the healthy hacker’s coffee stream. [Bharath] is among those who enjoy the caffeinated bean juice on a daily basis. However, he’d suffer from a terrible condition known as cold coffee. To combat this, he built an app-enabled, wirelessly chargeable, self-heating coffee mug.
We know that most hackers don’t start off planning to build objects with ridiculous feature lists, it just happens. Is there an alternate Murphy’s law for this? Any feature that can be added will? The project started off as some low ohm resistors attached to a rechargeable power bank. A insulated flask with a removable inner stainless steel lining was chosen. The resistors were fixed to the outside with a thermal epoxy.
However, how do we control the resistors? We don’t want to burn through our battery right away (which could end up more literally than one would like), so [Bharath] added a Linkit One microcontroller from Seeed Studio. With all this power at his disposal, it was natural to add Bluetooth, a temperature sensor, and app control to the cup.
After getting it all together, he realized that while the insides were perfectly isolated from the liquids held in the flask under normal use, the hole he’d have to cut to connect to the charging circuit would provide an unacceptable ingress point for water. To combat this he added the wireless charging functionality.
With his flask in hand, we’re sure the mood boost from not having to slog through the dregs of a cold container of coffee will produce a measureable improvement in productivity. Video after the break.
[prubeš] shows that parts printed with carbon fiber filament are as strong, or at least as stiff, as you’d expect. He then shows that his method for producing carbon fiber parts with a mixture of traditional lay-up and 3D printing is even stronger and lighter.
[prubeš] appears to be into the OpenR/C project and quadcopters. These things require light and strong parts for maximum performance. He managed to get strength with carbon fiber fill filament, but the parts weren’t light enough. Then he saw [RichMac]’s work on Thingiverse. [RichMac] designed parts with pre-planned grooves in which he ran regular carbon fiber tow with epoxy. This produced some incredibly strong parts. There’s a section in his example video, viewable after the break, where he tests a T joint. Even though the plastic starts to fail underneath the carbon fiber, the joint is still strong enough that the aluminum tube inside of it fails first.
[prubeš] innovation on [RichMac]’s method is to remove as much of the plastic from the method as possible. He designs only the connection points of the part, and then designs a 3D printable frame to hold them in place. After he has those in hand, he winds the tow around the parts in a sometimes predetermined path. The epoxy cures onto the 3D print creating a strong mounting location and the woven carbon fiber provides the strength.
His final parts are stronger than 100% infill carbon fill prints, but weighs 8g instead of 12g. For a quadcopter this kind of saving can add up fast.