Does it ever just kill you that someone in a factory somewhere got to have all the fun of assembling your bench tools? There are a lot of questionable circuit boards floating around the Internet, and they can replicate practically any section of a circuit. When it comes to putting a prototype these days you can pretty much just buy each block of your system’s overview flowchart and string them together. [GreattScott!] combines a few of these into a relatively useful variable power supply with current limiting.
Admittedly, this is more of academic exercise if your only metric for success is monetary savings. Comparable power supplies can be purchased for the same amount of local currency as the parts in this build. However, there is something to be said for making it yourself.
The core of this build is based around the LTC3780, a bit of silicon from LT that offers both buck and boost converting along with a current control mode. It’s useful for a lot of things. The here is rated for up to 130 watts of power, which makes is a decent amount of power for a bench supply.
With a few modifications, like replacing the world’s most untrustworthy potentiometers and adding a nice ABS box, the build is completed. Along the way, [GreatScott!] offers a few tricks for testing and some reminders of how not to make yourself dead when playing with electricity.
The end is a working lab bench supply project that can easily keep a hacker entertained on a lazy Sunday afternoon.
We’ll just come out and say it, [reboots] has friends with nice garbage. Sure, some of us have friends who are desperately trying to, “gift,” us a CRT monitor, hope dropping like a rock into their stomach when they realize they can’t escape the recycling fee. [reboots] has friends who buy other people’s poorly thought out CNC projects and then gift him with the parts.
After dismantling the contraption he found himself with nice US and Japanese made linear motion components. However, he needed a CNC controller to drive it all. So he helped another friend clean out their garage and came away with a FlashCut CNC controller.
Now that he had a controller and the motion components whirring nicely, he really needed a frame to put it all in. We like to imagine that he was at a friend’s barbeque having a beer. In one corner of the yard was an entire Boeing 747. A mouldering scanning electron microscope with a tattered and faded blue tarp barely covering its delicate instrumentation sat in another corner. Countless tech treasures were scattered about in various states. It was then that he spotted a rusting gamma ray spectrometer in the corner that just happened to have the perfect, rigid, gantry frame for his CNC machine.
Of course, his friend obliged and gladly gave up the spectrometer. Now it was time to put all together. The gantry was set on a scavenged institutional door. The linear motion frames were bolted in place. Quite a few components had to be made, naturally, of scrap materials.
Most people will start by using a handheld router for the spindle. The benefits are obvious: they’re inexpensive, easy to procure, and generally come with mounts. But, there are some definite downsides, one of the most glaring of which is the lack of true speed control.
Even routers that allow you to adjust the speed (a fairly common feature on new models) generally don’t actually regulate that speed. So, you end up with a handful of speed settings which aren’t even predictable under load. Furthermore, they usually rely on high RPMs to do their work. For those reasons, handheld woodworking routers aren’t the best choice for a mill that you intend to cut metal with.
[reboots] noticed this problem while building this machine and came up with an inexpensive way to build a speed-controlled spindle. His design uses a brushless DC motor, controlled through a hobby ESC (electronic speed control), which uses a belt to drive the spindle. The spindle itself is mounted using skateboard bearings, and ends in an E11 collet (suitable for light machining in aluminum).
With the ESC providing control of the brushless motor, he’s able to directly control the spindle speed via software. This means that spindle speeds can be changed with G-code, allowing for optimized feeds and speeds for different operations. The belt-drive increases torque while separating the motor from the spindle, which should keep things cool, and reduce rotating mass on the spindle itself. Now all [reboots] needs to do is add a DIY tool changer!
Virtual reality doesn’t feel very real if your head is the only thing receiving the virtual treatment. For truly immersive experiences you must be able to use your body, and even interact with virtual props, in an intuitive way. For instance, in a first-person shooter you want to be able to hold the gun and use it just as you would in real reality. That’s exactly what [matthewhallberg] managed to do for just a few bucks.
This project is an attempt to develop a VR shooting demo and the associated hardware on a budget, complete with tracking so that the gun can be aimed independent of the user’s view. [matthewhallberg] calls it The Oculus Cardboard Project, named for the combined approach of using a Google Cardboard headset for the VR part, and camera-based object tracking for the gun portion. The game was made in Unity 3D with the Vuforia augmented reality plugin. Not counting a smartphone and Google Cardboard headset, the added parts clocked in at only about $15.
Using corrugated cardboard and a printout, [matthewhallberg] created a handheld paddle-like device with buttons that acts as both controller and large fiducial marker for the smartphone camera. Inside the handle is a battery and an ESP8266 microcontroller. The buttons on the paddle allow for “walk forward” as well as “shoot” triggers. The paddle represents the gun, and when you move it around, the smartphone’s camera tracks the orientation so it’s possible to move and point the gun independent of your point of view. You can see it in action in the video below.
Tracking a handheld paddle with a fiducial marker isn’t a brand new idea; We were able to find this project for example which also very cleverly simulates a trigger input by making a trigger physically alter the paddle shape when you squeeze it. The fiducial is altered by the squeeze, and the camera sees the change and registers it as an input. However, [matthewhallberg]’s approach of using hardware buttons does allow for a wider variety of reliable inputs (move and shoot instead of just move, for example). If you’re interesting in trying it out, the project page has all the required details and source code.
This isn’t [matthewhallberg]’s first attempt and getting the most out of an economical Google Cardboard setup. He used some of the ideas and parts from his earlier DIY Virtual Reality Snowboard project.
A VMC (vertical machining center) is essentially a CNC vertical milling machine on steroids. Many CNC mills are just manual milling machines that have been converted to CNC control. They work nicely, but have a number of drawbacks when it comes to real world CNC milling: manual tool changes, lack of chip collection, lack of coolant containment, and backlash issues (which a manual machinist normally compensates for).
These problems are solved with a VMC, which will usually have an automatic tool changer, and an enclosure to contain coolant and wash chips down into a collection pan. They are, however, very expensive, very big, and very heavy. Building one from scratch is a massive undertaking, but one which [Chris DePrisco] was brave enough to take on.
The backbone of the cart is the Segway Mini Pro. An aluminium frame attaches to the Segway via an eye-bolt and two carabiners, the larger of which has some tape wrapped around it to reduce wear. A swivel caster is attached with u-bolts to support the weight of the rider along the middle of this makeshift go-cart. Pushing on a t-handle made of pvc — connected to the Segway’s knee brace with a simple strap — engages the motor in lieu of the normal lean-to-go-forward action. Turning is simply done by swinging the handle or pressing with your feet.
DIY medical science is fun stuff. One can ferret out many of the electrical signals that make the body run with surprisingly accessible components and simple builds. While the medical community predictably dwells on the healthcare uses of such information, the hacker is free to do whatever he or she wants.
If you had made it this far in your journey from project to kit, you would now have a box of electronic components, a pile of printed instructions, and a box of plastic bags, thin card boxes, or whatever other retail packaging you have chosen for your kit. You are ready to start stuffing kits.
It’s All In The Presentation
Your priorities when stuffing a kit are to ensure that your customer receives all the components they should, they can easily identify each component, and that the whole kit is attractively presented such that it invites them to buy or build it when they first see it. This starts before you have packed any components, you must carefully prepare each component into units of the required number and label them if they are otherwise not easy to identify. Pre-cut any components supplied on tape, and write the part number or value on the tape if it is not easily readable. You may even have to package up some difficult-to-identify components in individual labeled bags if they can not have their values written on them, though this incurs an extra expense of little bags and stickers. Some manufacturers will insist on using black tape on which an indelible pen doesn’t show up!
Take care cutting tapes of components, it is sometimes easy to damage their pins. Always cut the tape from the bottom rather than the side with the peelable film, and if necessary carefully bend the tape slightly to open up the gap between components for your scissors.
If you start by deciding how many kits you want to stuff in a sitting, list all the kit components and prepare that number of each of them in the way we’ve described. Then take the required number of packages or bags, and work through each component on the list, stuffing all the bags with one component before starting again moving onto the next. In time you will have a pile of stuffed kits ready to receive their instructions and labeling.
The next step will be to fold your instruction leaflet and pack it in the kit. Take a moment to consider how it can be most attractively presented. For example with a kit packaged in a click-seal plastic bag it makes sense to fold the leaflet such that the colour photo of a completed kit is visible from the front. And when you place it in the bag make sure that the PCB is visible top-outwards in front of it. A customer looking at your kit wants to immediately see what they are likely to create with it.
You can now seal the bag or box, the kit is packed. It only remains to give it a label that has all the pertinent information and is attractive to the customer. You will probably want to put your logo or web address on the label as well as any small print required, alongside the most important feature — the kit description. We’ve put a warning about small parts and curious children, you may also want to put any reglatory or compliance information here. For example in Europe you might have a CE mark and a WEEE logo. Once you have your design sorted you can run it up in your favourite label designing software – we used gLabels – and print as many as you like on sheets of sticky labels. We strongly suggest buying good quality branded labels, the extra money is well worth it when you consider that they will have much more reliable glue, and the extra cost per individual kit will be marginal. Pick a label size which fills a decent space and is easy to read on your packaging without being too big, we used 70mm x 37mm laser labels of which 24 can be had on a single sheet.
Your First Finished Product
It’s an exciting moment when you apply a label to your first fully packed kit and see for the first time what your customers will see: a finished product. You aren’t quite done though, because there is still the small matter of quality control. Take a kit or two from your batch at random, and count all their contents off against your list of what they should contain. This should help you ensure you are packing the kits correctly. Finally, give a completed kit to a friend who has never seen it before, and tell them to build it as a final piece of quality control. They are simulating your customer in every way, if they have no problems then neither should anyone who buys the kit.
Once you’ve built your batch of kits, you will now have the stock you will send out to your customers. Imagine yourself as a customer, if you order a kit you will expect it to arrive in pristine condition. You should therefore now take care of this stock of kits to ensure that it does not come to any harm, its packaging is as crisp and new when you send it out as when you packed it, and it has not attracted any dust while in storage. We would suggest having a separate plastic box for the stock of each kit in your range, and protecting the kits from dust with a lid, or by storing them inside a larger plastic bag.
As we’ve worked through this series of articles, we’ve tried to give you a flavour of the process of bringing an electronic kit from a personal project to the masses. We’ve looked at learning about the market for your kit, we’ve discussed turning a project into a product before writing the best instructions possible and now stuffing your first kits ready for sale. In the next article in the series we’ll talk about how you might sell your products, the different choices open to you for online shops, marketplaces, and crowdfunding.