Why You Should Own A Sewing Machine

This could probably be any of our grandmothers at work. George Grantham Bain Collection [PD], via Wikimedia Commons
This could probably be any of our grandmothers at work. George Grantham Bain Collection [PD], via Wikimedia Commons.
In our hackspace, we’ve opened a textile room in the last month. We have high hopes for it as a focal point for cosplayers and LARPers as well as the makers of wearable electronics and more traditional textile users. Putting it in has involved several months of hard work bringing a semi-derelict and previously flooded room that was once the walk-in safe for our local school authority to a point at which it is a light and welcoming space, but a surprising amount of work has also had to go into winning the hearts and minds of our community for the project.

Putting it quite simply, textiles aren’t seen as very cool, in hackspace terms. You know, Women’s stuff. Your mother does it, or even maybe if you are a little younger, your grandmother. It’s just not up there with laser cutting or 3D printing, and as a result those of us for whom it’s a big part of making stuff have had to fight its corner when it comes to resources within the space.

Yet not so long ago when I brought a pair of worn-out jeans into the space on a social night and hauled out our Lervia sewing machine to fix them, I had a constant stream of fellow members passing by amazed at what I was doing. “You can repair jeans?” they asked, incredulously. For some reason this prospect had not occurred to them, I was opening up a new vista in clothing reincarnation, to the extent that before too long in our new facility I may be giving a workshop on the subject as the beloved former trousers of Oxford Hackspace denizens gain a chance of new life.

The Oxford Hackspace textile room.
The Oxford Hackspace textile room.

One of the odd things about this seeming gulf between makers and textiles is that it works in both directions. Just as my hackspace friends had struggled to see the worth in textile work, so do my textile enthusiast friends often fail to bask in their level of technical achievement. Think about this from a hardware hacker perspective: their every project involves making a three-dimensional object in a flexible material that both fits an individual wearer perfectly and looks good on them, and all this by hand in a 2D medium using only tape measure readings and squared paper assuming they’re making their own pattern. Not a CAD package or rendered preview in sight! That’s 1337 levels of awesome, yet they take it for granted as something the’ve always done, because their mother or grandmother showed them how.

Now perhaps you’ll understand why we have high hopes of our textile space, these are people who can make anything, just the sort of members who’d be an asset to our space if we can attract them.

So you might be asking, that’s a description of textilists and one hackspace’s work in the field, what’s in it for me? Stick around, and we’ll take a look at the sewing machine not as your grandmother’s prized possession but as the original home machine tool, and maybe after you know something of how it works you’ll see why you should make space for one in your workshop.

Know Your Stitches

The most basic method of sewing involves doing it by hand, with a single needle and thread. The stitch you’d be most likely to create in this way is backstitch, in which you go back against the direction of sewing every other stitch to lock the line of stitches and stop it coming apart if a thread breaks. It’s very slow, and requires a considerable amount of skill to achieve a good result. It’s something you occasionally need to do even if you own a sewing machine, but unless you are making super-accurate recreations of historical clothing it’s not something you’ll use for a whole project.

An illustration of a sewing machine producing a lockstitch. NikolayS [CC-BY-SA-3.0], via Wikimedia Commons.
An illustration of a sewing machine producing a lockstitch. NikolayS [CC-BY-SA-3.0], via Wikimedia Commons.
The sewing machine can’t do a backstitch with a single thread as you might expect, it’s very difficult for a machine to pass the thread though the fabric in its entirety on each stitch. Instead it uses two threads to create a stitch called lockstitch, in which each thread stays on its own side of the fabric and interlocks with the other thread only through the holes made by the needle. The upper thread comes from a spool on the top of the machine while the lower one comes from a bobbin mounted underneath its operating surface. The action of making the lockstitch has been performed by a variety of mechanisms since the invention of the sewing machine, but in the majority of those you’ll encounter it is done through a rotating hook that surrounds the bobbin. This hook picks up a loop of the upper thread pushed through the fabric by the needle, and wraps it round the lower thread from the bobbin before the needle and upper mechanism pulls the upper thread tight back up through the hole. This produces reliable and consistent stitching that can be repeated at very high speed.

You can see that there’s a lot going on here: the machine has to supply the thread at the right speed and tension, hold the fabric in place, move it forwards at the correct speed, and keep the whole lot in synchronisation. Sewing machines are complex beasts.

Know Your Machine

A sewing machine has a needle mechanism over a flat surface, suspended from a horizontal arm to give enough bed width to position the work as necessary on either side of the needle. The overwhelming majority of machines have the horizontal arm coming in from the right, coming from a vertical arm that usually contains the motor and significant parts of the drive mechanism. On the extreme right hand side of the machine is a wheel on the outside that rotates as the mechanism operates, this might historically have had a hand crank or pulley for a treadle or external motor to power the sewing. It serves to allow the operator to manually advance the stitches very slowly, or to back off the mechanism. On older machines it will be a large metal pulley that harks back to the hand-cranked or treadle days, while on newer ones it will usually take the form of a plastic knob.

The various parts of a sewing machine. [Public domain], via Wikimedia Commons
The various parts of a sewing machine. [Public domain], via Wikimedia Commons.
To the left of the pulley are the two arms containing the gears, shafts, or belts transfer motion to the needle and down to below the bed of the machine. The controls to select functions and adjust stitch length, a bobbin winder, and a light are usually mounted on the outside of the arms, and the spool of thread sits on a pin on top of the machine

At the far left of the horizontal arm and the bed, we have the business end of the machine: the needle, and the bobbin assembly. We’ll consider these from the top downwards, as they are all roughly in a line in that axis.

On most machines you can remove the plate or cover on the end of the horizontal arm that conceals the mechanism. If you were to remove it and look at the end of the arm face-on you’d see the end of the drive shaft with a crank that drives the mechanism that raises and lowers the needle. This crank also operates the thread take-up lever which normally protrudes from the front casing, this has the thread looped round it and has the function of pulling the loop of thread back up through the fabric on each individual stitch. There will also be a thread tensioner, similar to a pair of washers clamping the thread with the force of a small spring.

The arm end mechanism of a classic Singer 185K. The tensioner and thread take-up lever are on the right, while the lamp and presser foot lever are on the left.
The arm end mechanism of a classic Singer 185K. The tensioner and thread take-up lever are on the right, while the lamp and presser foot lever are on the left.

Vertically the entire height of the machine at the end of the arm will be two bars. Towards the front of the machine will be the needle bar with the needle attached to its bottom, while behind it will be the presser foot bar. The presser foot at the bottom of this bar serves the purpose of holding the fabric down on the bed of the machine, and can be raised or lowered with a lever on the back of the machine.

Below the presser foot is the bed of the machine, and below that is the bobbin and hook mechanism described above. Either side of the needle are a pair of toothed dogs that act on a crank to “walk” the fabric past the needle.

If you have followed the description in the last few paragraphs you will now have a good idea of the working of a simple straight-stitch sewing machine. These were the standard from the middle of the nineteenth century until sometime in the 1960s when domestic machines capable of other stitches such as zig-zags or dual-row stitching appeared. These machines have an extra mechanism that allows the needle to move from side to side as well as up and down, something controlled at first by selectable cams but on more recent machines by a microcontroller.

Once you have a sewing machine, what might you do with it? Of course, like any other versatile tool or machine, the answer is limited only by your imagination or your favourite search engine. And there should be no reason for you to have to use if for making garments if that’s not your thing, there are a huge number of places a maker can find use for a bit of textile work in their projects if only they have the means to work in the medium. I make the occasional garment project and have been used for a few Halloween costumes, but by far the most use they see are in repairing and modifying things I already have. From fixing the frayed edge of my day pack to mending those treasured but past-it jeans and saving a caravan holiday when my friend’s awning was found to have a rip, they are as important tools to me as my multimeter or oscilloscope.

Finding The Machine For You

If you’ve made it this far and fancy looking for a sewing machine to grace your own bench, where should you start? Given that this is a product which has been in production for over 150 years, you have a huge array of machines to choose from.

It’s worth beginning at the end of the market that you might not expect us to tackle first, and look at new machines. A new machine might cost more than a second-hand one, but if you buy wisely you should be able to secure plenty of modern features without breaking the bank. Of course just like any tool it is possible to pay a four or five figure sum at the top end of the market, and if that’s the course you take you’ll get what you pay for in the form of a very high quality machine. But if that describes you then you probably won’t need our advice. We’re more interested in the other end of the market for the purposes of this article.

The Brother L14, a typical budget sewing machine from a quality manufacturer.
The Brother L14, a typical budget sewing machine from a quality manufacturer.

If you take a look at any department store website, you’ll find a range of budget sewing machines. At the bottom end of the price range, some of them are astoundingly cheap coming in at $50 or under. These are usually own-brand machines aimed at younger users, a sort of “My first sewing machine” product. It’s probably best to view these machines as having more in common with a toy than your grandmother’s trusty Singer, and avoid them. You can make all sorts of things with one, but do not expect it to be robust, or to last long when used for heavy-duty work.

Happily on the next step up from the toy machines are the base models from quality manufacturers. These share the metal components and reliability of their more expensive brethren, but lack some of the premium features. They will normally have a range of stitches, but their mechanisms will be entirely mechanical rather than computerised. If you have somewhere above $100 to spare they make an excellent choice for someone seeking a workaday sewing machine.

In the second-hand market you have that century or more of machines to choose from, and some machines can command eye-watering prices while others are almost worthless. It’s best to start with the more recent machines and move backwards in time to catch the sweet spots.

Oxhack's Jones, as it happens another Brother in disguise. Inexpensive and unfashionable, but loads of features and just as good at sewing as it was when it was new.
Oxhack’s Jones, as it happens another Brother in disguise. Inexpensive and unfashionable, but loads of features and just as good at sewing as it was when it was new.

Most premium machines from the late 1960s through to the 1990s have all the modern features of the day such as the range of stitches, and were depending on the manufacturer built to a very high standard. They are however quite heavy and extremely dated in their appearance, so can often be found in very good condition in the want-ads for not a huge amount of money. A quick scan while writing this piece finds a range of similar machines including ones from very expensive manufacturers advertised for similar prices to the toy machines mentioned earlier. Exchange rates are in a state of flux at the moment so it’s probably unwise to do a conversion, but £25 to £50 seems to get you a lot of features if you don’t mind a machine that’s sewed a few shoulder pads in its time.

Older machines come from an unbroken line stretching from the 1850s to the 1960s. They all perform very well the single task of stitching in a straight line, and by the early twentieth century their design had evolved to the point at which they were all fairly similar mechanically. The earlier models made before about the First World War are probably best considered for our purposes here as museum pieces, it is the later ones from the second quarter of the century onwards that should interest us.

Earlier machines like the one in the black-and-white picture at the top of the page were made to be objects of beauty in their own right. They were richly decorated, and there are collectors who buy them for this decoration. As with any field in which collectors move in their prices can thus climb to the point at which a buyer looking only for a usable sewing machine is priced out of the market for them.

A Singer 185K from the late 1950s. Brown was fashionable then.
A Singer 185K from the late 1950s. Brown was fashionable then.

The good news for us comes from mid-century fashion. In the 1950s the decorated machines with their curved castings were seen as ugly and outdated, and customers demanded clean lines with modern hues. Thus the manufacturers took the machines they had been making for decades and reclad them in more angular bodies painted with contemporary colours. Fashion is a funny thing, because these dull brown and green sewing machines are now unwanted and unloved, despite being mechanically identical to their curved and decorated predecessors. This is good news because it means their worth is much less, and persistence may well net you one for something close to beer money.

These 1950s and early 1960s machines are built to an extremely high standard, and will sew anything you can throw at them. They’ll probably outlast almost everything else you own. You do need to summon your inner weightlifter to heft one, and they don’t lend themselves to easy shipping. If you can do without any fancy stitches they represent something of a sweet spot, and we’d recommend them as a good place to start if you can get your hands on one.

Have you changed your mind about textile work reading this article, and are you about to scour your parents loft for your grandmother’s forgotten sewing machine? On a hardware hacker’s bench a sewing machine is just another machine tool, and it’s probably one you can’t afford to be without.

Header image: US patent US2430932A.

A Modest But Well-Assembled Home Hydropower Setup

We have all opened an electricity bill and had thoughts of saving a bit of money by generating our own power. Most of us never get any further than just thinking about it, but for anyone willing to give it a try we are very fortunate in that we live in a time at which technology has delivered many new components that make it a much more straightforward prospect than it used to be. Electronic inverters, efficient alternators, and electronic battery management systems are all easy to find via the internet, and are thus only a matter of waiting for the courier to arrive.

Pelton Wheel
Pelton Wheel

[Frédéric Waltzing] is lucky enough to have access to a 135 foot (38 metre) head of water that those of us in flatter environments could only dream of. He’s used it to generate his own power using a modestly sized but very effective turbine, and he documented it in a Youtube video which you can see below the break.

He brings the water to his turbine house through a 1.5 inch plastic pipe, in which he maintains a 55PSI closed pressure that drops to 37PSI when the system is running. His Pelton wheel develops 835RPM, from which a small permanent magnet alternator provides 6.3A for his battery management system. An Enerwatt 2KW inverter provides useful power from the system.

This hydroelectric installation might not be very large, but its key is not in its size but that it can run continuously. A continuous free 6.3A charge can store up a lot of energy for those times when you need it.

Continue reading “A Modest But Well-Assembled Home Hydropower Setup”

Life on Contract: How to Find Clients as an Engineering Contractor

The following is my personal advice, it probably doesn’t apply to all contractors, but it’s certainly applied to me. When you start contracting, your most pressing question is probably “how do I find clients” so here’s what little I’ve learned so far…

1. Don’t

For some, contracting is seen as a potential escape route from the hum-drum of a dull, often political office environment. But contracting isn’t always the answer. Pay, while often better, is inconsistent. I’ve had clients pay two months late (and think it’s normal), pay the wrong amount (due to misunderstanding currency conversion) and just plain forget to sign off an invoice. Chasing down these invoicing issues will all be your job. Clients will say “we’ll definitely hire you” and then a contract will never happen.

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Botnet Recall of Things

After a tough summer of botnet attacks by Internet-of-Things things came to a head last week and took down many popular websites for folks in the eastern US, more attention has finally been paid to what to do about this mess. We’ve wracked our brains, and the best we can come up with is that it’s the manufacturers’ responsibility to secure their devices.

Chinese DVR manufacturer Xiongmai, predictably, thinks that the end-user is to blame, but is also consenting to a recall of up to 300 million 4.3 million of their pre-2015 vintage cameras — the ones with hard-coded factory default passwords. (You can cut/paste the text into a translator and have a few laughs, or just take our word for it. The company’s name gets mis-translated frequently throughout as “male” or “masculine”, if that helps.)

Xiongmai’s claim is that their devices were never meant to be exposed to the real Internet, but rather were designed to be used exclusively behind firewalls. That’s apparently the reason for the firmware-coded administrator passwords. (Sigh!) Anyone actually making their Internet of Things thing reachable from the broader network is, according to Xiongmai, being irresponsible. They then go on to accuse a tech website of slander, and produce a friendly ruling from a local court supporting this claim.

Whatever. We understand that Xiongmai has to protect its business, and doesn’t want to admit liability. And in the end, they’re doing the right thing by recalling their devices with hard-coded passwords, so we’ll cut them some slack. Is the threat of massive economic damage from a recall of insecure hardware going to be the driver for manufacturers to be more security conscious? (We kinda hope so.)

Meanwhile, if you can’t get enough botnets, here is a trio of recent articles (one, two, and three) that are all relevant to this device recall.

Via threatpost.

Etching Your Own Metal

It’s been said that with enough soap, one could blow up just about anything. A more modern interpretation of this thought is that with enough knowledge of chemistry, anything is possible. To that end, [Peter] has certainly been doing a good job of putting his knowledge to good use. He recently worked out a relatively inexpensive and easy way to etch metals using some chemistry skill and a little bit of electricity.

After preparing a set of stencils and cleaning the metal work surface, [Peter] sets his work piece in a salt solution. A metal bar is inserted in the other end of the bath, and both it and the work piece are connected to electrodes. The flow of electricity removes some metal from the exposed work surfaces, producing whatever patterns [Peter] wants.

One interesting thing that [Peter] found is that the voltage must stay under 6 volts. This is probably part of the reason it’s relatively easy to etch with even a wall wort. Above that, the iron work piece produces a different ion which can clog the work surface and create undesirable effects. Additionally, since his first experiments with this process he has upgraded the salt bath with magnetic stirrers. He also gets the best results in a very cold environment.

There are many other uses for etching metals, too. Creating your own printed circuit boards comes to mind, but there are plenty of other uses as well. What will you do with this technique?

Hackaday Prize Entry: A Cluster Of Exoskeletons

The current trend of 3D printed prosthetic hands have one rather large drawback: you can’t use them if you already have two hands. This might seem like a glib objection, but one of last week’s Hackaday Prize posts pointed this out rather well – sometimes a meat machine needs mechanical assistance.

BEOWULF, [Chad Paik]’s entry for the Hackaday Prize, is the answer to this problem. It’s a mechanical exoskeleton for grip enhancement, stroke rehabilitation, and anyone else that doesn’t have the strength they need to get through the day.

This project solves the problem of weak arm strength through – you guessed it – 3D-printed parts, a linear actuator on the forearm, and a few force sensors on the fingertips. Control is obtained through a Thalmic Labs Myo, but the team behind the BEOWULF is currently working on a custom muscle activity sensor that is more compact and isn’t beholden to VC investors. You can check out a video of this exoskeleton below.

Continue reading “Hackaday Prize Entry: A Cluster Of Exoskeletons”

A Spreadsheet For Guesswork

Ever wish you could guess more precisely? Or maybe just make your guesses look confusingly legitimate? Guesstimate could help.

It uses Monte Carlo simulations to add some legitimacy to the ranges given to it. For example, if you say the cost of lumber for your next project could be between 2 and 8 dollars a piece, you don’t typically mean that it’s equally likely to be any of those numbers. Most people mean that the boards are most likely to be around 3-5 dollars and everything lower or higher is less probable. Using different shaped distributions, Guesstimate can help include this discrepancy of thought into your pseudo-calculations.

It’s a neat bit of code with a nice interface. There is a commercial side to the project for those who want to collaborate openly or pay someone to host it privately. It has a few neat example models for those interested.

Does anyone use anything like this in their daily lives? Is there another similar project out there? This kind of thing is pretty cool!