Tag Archives: electronics

The Process of SkeinMinder Design

It’s been a pretty busy couple of months!  I’ve been going full speed on SkeinMinder design, whipping it into production-ready shape.  When I show the pre-production Minder to my non-engineery friends, they tend to get a glazed look in their eyes, shake their head, and think that I’ve somehow magically conjured this mysterious circuit-board-thing out of thin air.  Well, it’s not magic, though it still feels kind of magical when you email files off and get real parts in the mail.  And it’s even more magical when those parts actually work just like you expect them to.  OK, maybe there is some magic involved.  And magnets.  There are definitely magnets.

But seriously, how does one techie chick with a computer and a small home workshop (and maybe like 12 years of PCB widget manufacturing experience) pull off a serious product design?  Let’s find out!

First, I cobbled together a proof-of-concept model out of off-the-shelf-parts, jumper wires, and breadboards.  (Apparently the original electronics breadboards really were boards used for cutting bread.  Crazy, eh?)  This let me play around with the idea without spending a lot of money.  A lot of ideas seem simple at first, but when you actually try to implement them, they grow in complexity.  A proof-of-concept allows you to suss out the main technical challenges right away.  Most of the software development I’ve done, and probably the setup with the most winding hours on it, is my initial messy-looking jumble-of-wires POC model:

Not too inspiring-looking, huh?  I cobbled together an Arduino Mega2560 processor board, an LCD and some buttons on a breadboard, and I started off with a Powerswitch Tail for turning on and off AC power.  Pretty much all of these parts are plug-and-play.  I didn’t even solder anything.  After a couple months of pulling C programming out of very dusty corners of my brain, I had something that totally worked.  Yay!

You might think that at that point, the majority of the work was done.  Heh.  The real work had just begun.

Ok, so I had this thing that totally “worked” on the bench.  Too bad that I couldn’t move it from the bench for fear of the wires coming loose.  Not to mention that when I wiggled some of them, weird things would happen.  Enter Phase 2 (aka, the ??? phase).  I needed to make a prototype.  And not just one that I could move around, but one that I could give to someone else to use.  Other people will always do things you didn’t expect.  Especially in the SkeinMinder’s case – every dyer has a slightly different setup.  We have different brands of winders, different swifts, we wind different numbers of skeins at a time of different types of yarn.  It was impossible to sit on my couch and predict how all of those factors would affect the Minder’s behavior.  So I got my first prototype into the hands of a dyer friend pretty early.  I wanted to know if the assumptions I made about how the Minder would be used corresponded to the reality of how it was actually used.

Better-looking, right?  The prototype was a first shot at parts I thought I would actually use in the production unit.  The Mega2560 was totally overkill for the job, so I switched to an Arduino Pro Mini with the 328P chip.  I soldered the breadboards together, wired up buttons and connectors, and shoved everything in a generic box.  I still kept the 120VAC switching as a separate Powerswitch Tail unit, though I also started to prototype my own power-switching unit using a Sparkfun SSR kit.  I also bought a lot of experimental parts at the time.  I think I went through 8 LCD displays, at least a dozen large buttons, and probably 50 small buttons until I got the look and feel that I wanted.  While simultaneously making sure the parts were readily available and wouldn’t make the Minder too expensive.  It turns out that 90% of good engineering design is being good at shopping.

One person testing your design is great, but more is better.  I decided to form a beta group of about 5 companies, all with different winders and winding needs.  I put out a few feelers to friends and colleagues, and happily got immediate and highly interested responses.  That was incredibly inspirational and motivational.  I had been trying to decide how “real” to make the beta units.  I knew I couldn’t hand-wire 5-10 more units like I had the prototype, there was too much wiring, too much potential for mistakes or intermittent connections.  After seeing those responses, I pretty much knew my answer.

Twelve years of experience with making electronics widgets has taught me this: when you think you have everything totally designed for production and set, you generally will learn something new from those units and need one more revision.  It seemed like the right thing to do was this: make what I considered to be completely ready production units, and deliver those to the beta group.  They’d still probably need one more revision, but it was not likely to be major.  I want to have a pretty well vetted design before launching a Kickstarter campaign for the SkeinMinder.  Pre-selling a mostly new design as a production unit is really just a recipe for missed expectations and a faking-your-own-death-on-the-internet style of disaster.

Designing for production, then.  Let’s do this custom circuit board thing!  This is probably the most magical step to most people.  It’s still pretty darned cool to me too.  I mean, I basically play an advanced version of connect-the-dots for a while and generate something that looks like this:

SM Processor Snapshot

And then I upload and order it and get a rendering that looks like this:

And then the actual part comes in the mail and looks like this:

And then when it’s all soldered together, it looks like this:

And when the code is loaded and it’s up and running, it looks like this:

Ideas to reality, just like that!

While I was designing the circuit boards (there are 2 in the SkeinMinder), I was simultaneously developing the mechanical box design and layout.  There are a lot of mechanical constraints – connectors are a certain size and some are relatively fixed, the LCD is a certain height, the small buttons are a different height that need to be adjusted to correspond to LCD height, the big red button is a certain depth, the power switching parts need clearances and heat sinks, the buttons need to be far enough apart to push easily, and NEVER FORGET TO LEAVE ROOM FOR MOUNTING HOLES.  To top it off, circuit boards are generally priced by the square inch.  So the smaller you can make them, the less expensive they will be to make.  Does this sound like a bunch of conflicting requirements that requires a good deal of spacial awareness to resolve?  :)  I love it.  Hate Rubik’s cubes, love tricky circuit board layout.

When the circuit board design was done, the final mechanical enclosure design basically fell out of it.  I do have fancy circuit board software, but I don’t have fancy mechanical design software.  Plus, the box itself was an off-the-shelf part, so I really just needed to make drawings for the custom machining operations that indicated hole size, shape, and location.  It was a total pain in the ass, but I managed to browbeat my circuit board software into spitting out some 2D mechanical drawings.

SM Mech Drawings

Which the box company turned into much nicer drawings.

Polycase_snip

Which UPS has told me has turned into boxes that are shipping to me today!

Some of you might be asking yourselves “Couldn’t she have saved some money on the beta units by drilling those holes and cutouts by hand?”  Uh, actually, no.  ABS plastic is a pain in the ass to work using hand tools.  It tends to melt and spooge out of the way instead of cut nicely.  Holes turn out oblong for no apparent reason.  The centerpunch always manages to slip at the last minute, making your hole locations off so you have to drill them out.  I did manage to do one box by hand, and it’s even good enough for some very controlled beauty shots, but I wouldn’t give that ugly ducking to a paying beta tester, that’s for sure.  If I’m going to make a production unit, it’s going to look like a production unit.

Lastly (I know, right?  There’s yet another thing?!), there was the overlay design.  I originally thought about having a custom membrane switch made for the top.  They’re the style used on a lot of kitchen appliances and cheap remote controls.  They’re relatively flat plastic but have little domed buttons you press.  Well, a full-on custom membrane switch with the integrated buttons and flexible circuitry was prohibitively expensive.  Even in quantities of 100, they were still $50ish each.  Not including setup costs.  So that wasn’t gonna happen.  The next best thing (and much less expensive thing) was a custom plastic label with embossed sections, which would stick to the top of the cover and over physical button stalks that would poke up through holes in the cover.  It was mechanically more complex for me to implement because I had to coordinate button placement on the circuit board , hole cutouts in the cover, and embossed sections on the overlay.  But they’re  only about $8 in qtys of 100, have good tactile feel from the physical buttons, yet have the same professional look of a membrane switch, so they’re a much better solution.

Overlay_snip

I should also mention that the overlay is the one place where I sought external professional help.  As much as I’m good with dyes and yarn and circuit boards, I am not so good with graphic design.  I mean, I have a discriminating eye and can tell you what I like and don’t like and why, but when I put something together myself, it tends to look like it was done by an engineer.  You know?  Everything is too square and neat.  I’m fortunate to work with a terrific graphic designer (who is also a terrific knitter), Kimberly Roy, who put the finishing touches on the SkeinMinder.

Why the fancy overlay in the first place?  I mean, why not just use a sticker with some holes for the buttons?  Well, if you’ve ever done a boatload of yarn winding, you’ll know exactly why.  It’s pretty dirty business.  Dust and tiny little yarn fibers go everywhere and pile up, and I don’t want them to get into the enclosure and muck up the button works.  It’s also nice to have a clear plastic layer over the LCD, to protect it from scratches.  Plus, it also gives the enclosure a tiny bit more splash resistance for when you knock your beer over.  :)

So, yeah.  That was pretty much my July and August right there.  Everything from designing circuit boards to specifying enclosures, to designing overlays.  I can’t even tell you how rewarding it is to see it all coming together.  My poor friends are getting pictures of electronics and texts with A LOT OF CAPSLOCK AND EXCLAMATION POINTS EVERY DAY!!!!!

Are you ready for a peek?  Fortunately you can’t see my really badly hand-drilled misaligned holes though the paper overlay mock-up.  :)

Drumroll, please.  May I present….

The SkeinMinder ™

Not bad for a techie chick with a computer and a small workshop, huh?

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So What’s Next? Part II (finally!)

Electronics

If you know me in real life, or if you’ve been following me on instagram, this next part won’t be a surprise because you’ve probably seen some pictures like this:


If you only know me through fiber, here’s a little background to catch you up.

I didn’t always dye yarn.  In fact, yarn is somewhat of a 90 degree turn in the great “My Life Thus Far” story.  I graduated from college in the late 90’s with a degree in engineering, and spent about 11 years designing and building autopilots for small unmanned aircraft, also called UAVs.  I worked for small companies, on fast-paced projects with small teams and limited budgets.  I learned a ton about how to design electronics and build them in the 100s to 1000s, using entirely domestic manufacturing.  It turns out that this is highly applicable to building just about any device that uses electricity.

It’s fun to see how much the maker movement is exploding right now.  There are so many great kits and parts that make getting a project going SOOOOO much easier and cheaper than it used to be.  I mean, we used to do a lot of simple quick-turn prototype boards to test out some new sensor and see how it integrated with our existing electronics, or lay the groundwork for using it in a new design.  Now you can buy a lot of that stuff from Sparkfun or Adafruit for under $10.  It’s really given me a renewed excitement about electronics, and my brain is abuzz with ideas for linking things together, and making useful gizmos that will help a dyer out.

Above is an early peek at the guts of a project I’m currently working on and hope to launch on Kickstarter later this year. This one goes out to all of you folks who are tired of babysitting your skeinwinder.  You’ve stood there for hours, watching it count up to 200, then flipping the switch to turn it off.  You’ve known that there has to be a better way, a way that won’t turn you into a brainless zombie staring at a tiny LCD, zoning out and only realizing it when it’s at 247 and then having to stop it in a panic and manually unwind 47 turns and manage a spaghetti pile of yarn that hopefully won’t get tangled and make the next skeins a nightmare, and……..yeah, we’ve all been there.  What you need is:

The SkeinMinder

The SkeinMinder ™ keeps watch for you.  It turns your winder off when it’s done winding your custom 423 yd skeins off of cones.  It turns your winder off when it’s done re-skeining from your 2 yd dye hanks into your 1.5 yd final put-ups.  It turns your winder off when there’s a giant snarl that brings everything to a screeching halt.  It minds your winder, so you’re free to get back to the dyepots.  So you can use that brain of yours to create and sell more awesome yarn.

The SkeinMinder is not an electric winder.  It’s a single control box, about the size of a….package of Trader Joe’s Authentic Feta Cheese?  Box of uncondensed soup?  1 lb bag of coffee?  Brick? – that sits on a table.  You plug it into the wall, you plug your winder into it, and you attach a very simple rotation counter and magnet.  It has one big red GO button and some smaller buttons for changing the rotation set point and other stuff.

I really want it to have a super giant red button like this one in the final version.  We’ll see if it works out.

Think you could use something like this?  Want one right now?  Please fill out this very short questionnaire, it’ll help me get an idea of your current setup and needs.

Have no earthly need for this, but know a hand-dyer or two who might?  Please help me spread the word.  Email them, share this post on whatever social media you hang out on, or do it the old fashioned way and tell them when you see them next.  Thanks, your help is very much appreciated!

At this very moment, the first handmade (with love) prototype is currently being put through its paces by my friend Sincere Sheep, because you never really find out what things suck until you give your project to someone else.  :)  Which is why Uncle Alpenglow NEEDS YOU!  I need FIVE highly motivated and communicative individuals to be early beta testers of the next version, which will be the first pre-production Minders.

What do you get?  You get to be in on the ground floor of development for an exciting new product in your industry, even before the Kickstarter campaign is public!  You get an early version that is hand-assembled, but made with production parts.  You get it at a discount, with a free swap-out for the final production model.  You get to make your needs known, and help tailor it to be the most useful yarn tool EVER.  You also get my undying (or maybe dyeing?) love and a thank-you pile of naturally dyed yarn if you’re into that sort of thing.  I’m looking for businesses with some specific needs, so please fill out the questionnaire.  Be sure to select the “Yes!  Me, please!” button.  If it looks like you’re a good fit, I’ll let you know!

If you just want to be kept in the loop about the SkeinMinder and the Kickstarter campaign when it happens, please let me know with the form below.  There will be lots of yarny goodies for the fiber person who wants to be supportive of small hand dyers, but does not need a SkeinMinder themselves.  :)  Just wanted to let you know.

I also want to let you know that this is just the beginning.  I have ideas for even simpler tools.  I have ideas for a really really REALLY really really cool drop spindle.  I have more ideas than I can shake a soldering iron at.  I can’t wait to turn them into reality.

Read the next SkeinMinder post


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