Stepper motors divide a full rotation into hundreds of discrete steps, which makes them ideal to precisely control movements, be it in cars, robots, 3D printers or CNC machines. Most stepper motors you’ll encounter in DIY projects, 3D printers, and small CNC machines are bi-polar, 2-phase hybrid stepper motors, either with 200 or — in the high-res variant — with 400 steps per revolution. This results in a step angle of 1.8 °, respectively 0.9 °.
In a way, steps are the pixels of motion, and oftentimes, the given, physical resolution isn’t enough. Hard-switching a stepper motor’s coils in full-step mode (wave-drive) causes the motor to jump from one step position to the next, resulting in overshoot, torque ripple, and vibrations. Also, we want to increase the resolution of a stepper motor for more accurate positioning. Modern stepper motor drivers feature microstepping, a driving technique that squeezes arbitrary numbers of microsteps into every single full-step of a stepper motor, which noticeably reduces vibrations and (supposedly) increases the stepper motor’s resolution and accuracy.
On the one hand, microsteps are really steps that a stepper motor can physically execute, even under load. On the other hand, they usually don’t add to the stepper motor’s positioning accuracy. Microstepping is bound to cause confusion. This article is dedicated to clearing that up a bit and — since it’s a very driver dependent matter — I’ll also compare the microstepping capabilities of the commonly used A4988, DRV8825 and TB6560AHQ motor drivers.
This article is the fifth in a series looking at the process of bringing an electronic kit to market from a personal project. We’ve looked at market research, we’ve discussed making a product from your project and writing the best instructions possible before stuffing your first kits ready for sale. In this article we’ll tackle the different means of putting your kits out there for sale.
Given a box of ready-to-sell kits, what next? You have to find some means of selling them, getting them in front of your customer, making the sale, sending them to the purchaser, and safely collecting their money. A few years ago this was an expensive and risky process involving adverts in print magazines and a lot of waiting, but we are fortunate. The Internet has delivered us all the tools we need to market and sell a product like an electronic kit, and in a way that needn’t cost a fortune. We’ll now run through a few of those options for selling your kits, before looking at shipping, marketing, and post-sales support in the final article in the series.
I bet the hand saw really changed some things. One day you’re hacking away at a log with an ax. It’s sweaty, awful work, and the results are never what you’d expect. The next day the clever new apprentice down at the blacksmith’s shop is demoing his beta of his new Saw invention and looking for testers, investors, and a girlfriend. From that day onward the work is never the same again. It’s not an incremental change, it’s a change. Pure and simple.
This is one of those moments. The world of tools is seeing a new change, and I think this is the first of many tools that will change the way we build.
Like most things that are a big change, the components to build them have been around for a while. In fact, most of the time, the actual object in question has existed in some form or another for years. Like a crack in a dam, eventually someone comes up with the variation on the idea that is just right. That actually does what everything else has been promising to do. It’s not new, but it’s the difference between crude and gasoline.
My poetic rasping aside, the Shaper Origin is the future of making things. It’s tempting to boil it down and say that it’s a CNC machine, or a router. It’s just, more than that. It makes us more. Suddenly complex cuts on any flat surface are easy. Really easy. There’s no endless hours with the bandsaw and sander. There’s no need for a 25,000 dollar gantry router to take up half a garage. No need for layout tools. No need to stress about alignment. There’s not even a real need to jump between the tool and a computer. It can be both the design tool and the production tool. It’s like a magic pencil that summons whatever it draws. But even I had to see it to believe it.
Imagine this: you come home after a day at work. As you open the door, your nose is the first alert that something is very, very wrong. Instead of the usual house smell, your nose is assaulted with the distinctive aroma that means your dog had an accident. The smell is stronger though — as if Fido brought over a few friends and they all had a party. Flipping the lights on, the true horror is revealed to you. This was a team effort, but only one dog was involved.
At some point after the dog’s deed, Roomba, your robot vacuum, took off on its scheduled daily run around the house. The plucky little robot performed its assigned duties until it found the mess. The cleaning robot then became an agent of destruction, smearing a foul smelling mess throughout the space it was assigned to clean. Technology sometimes has unintended consequences. This time, your technology has turned against you.
This scene isn’t a work of fiction. For a select few families, it has become an all too odoriferous reality just begging for a clever fix.
When the story of an invention is repeated as Received Opinion for the younger generation it is so often presented as a single one-off event, with a named inventor. Before the event there was no invention, then as if by magic it was there. That apple falling on Isaac Newton’s head, or Archimedes overflowing his bath, you’ve heard the stories. The inventor’s name will sometimes differ depending on which country you are in when you hear the story, which provides an insight into the flaws in the simple invention tales. The truth is in so many cases an invention does not have a single Eureka moment, instead the named inventor builds on the work of so many others who have gone before and is the lucky engineer or scientist whose ideas result in the magic breakthrough before anyone else’s.
The history of computing is no exception, with many steps along the path that has given us the devices we rely on for so much today. Blaise Pascal’s 17th century French mechanical calculator, Charles Babbage and Ada, Countess Lovelace’s work in 19th century Britain, Herman Hollerith’s American tabulators at the end of that century, or Konrad Zuse’s work in prewar Germany represent just a few of them.
So if we are to search for an inventor in this field we have to be a little more specific than “Who invented the first computer?”, because there are so many candidates. If we restrict the question to “Who invented the first programmable electronic digital computer?” we have a much simpler answer, because we have ample evidence of the machine in question. The Received Opinion answer is therefore “The first programmable electronic digital computer was Colossus, invented at Bletchley Park in World War Two by Alan Turing to break the Nazi Enigma codes, and it was kept secret until the 1970s”.
It’s such a temptingly perfect soundbite laden with pluck and derring-do that could so easily be taken from a 1950s Eagle comic, isn’t it. Unfortunately it contains such significant untruths as to be rendered useless. Colossus is the computer you are looking for, it was developed in World War Two and kept secret for many years afterwards, but the rest of the Received Opinion answer is false. It wasn’t invented at Bletchley, its job was not the Enigma work, and most surprisingly Alan Turing’s direct involvement was only peripheral. The real story is much more interesting.
When was the last time you went to a library? If it’s been more than a couple of years, the library is probably a very different place than you remember. Public libraries pride themselves on keeping up with changing technology, especially technology that benefits the communities they serve. No matter your age or your interests, libraries are a great resource for learning new skills, doing research, or getting help with just about any task. After all, library science is about gathering together all of human knowledge and indexing it for easy lookup.
It doesn’t matter if you’re not a researcher or a student. Libraries exist to serve everyone in a class-free environment. In recent years, patrons have started looking to libraries to get their piece of the burgeoning DIY culture. They want to learn to make their lives better. Public libraries have stepped up to meet this need by adding new materials to their collections, building makerspaces, and starting tool libraries. And this is in addition to ever-growing collections of electronic resources. Somehow, they manage to do all of this with increasingly strained budgets.
The purpose of this article is to explore the ways that libraries of all stripes can be a valuable resource to our readers. From the public library system to the sprawling academic libraries on college campuses, there is something for hackers and makers at all levels.
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.