Thursday, March 8, 2018

DIY Thermal Vision Camera for < $100

Now, you too can see heat maps of human bodies or car engines like Predator - or identify cold spots and drafts in your house like a home-energy expert. And with a little DIY electronics knowledge, you can do it really inexpensively.

Although the sensor is only an 8x8 array, you can interpolate the readings to emulate a finer grain, and with a little coding, adjust how the temperatures are shown.

A big price-drop on Panasonic's AMG8833 8x8 Grid-EYE thermal sensor array has finally allowed hobby electronics suppliers to create a fun and useful thermal camera at a price everyone can afford - less than $50. Compare that to the more than $250 for a FLiR dev board with an 80x60 grid.

As you might expect at this price point, there are limitations. The sensor is only 8x8 pixels and has a range of less than 25 feet (7 meters). You will not be able to identify enemy paintballers from across the battlefield, and you can't get a full-house image of your heat loss. It requires a brain (Arduino or RasPi) with I2C, libraries and a graphics screen. Most people reading this probably already have a microcontroller and screen, so that's no big deal. But faster processors will give you smoother video feeds.

Here's a great teaser video from Adafruit on how to make this into a cute camera version.

Looks cool right, then see the full tutorial and make one of your own.

Adafruit has two versions of the sensor module: a tiny breakout board (item# 3538) and a Featherwing daughter board (item# 3622) made to snap right into any of their Feather boards. And of course the best thing about getting the Adafruit version is their high quality libraries and well written tutorial. They even have a tutorial on hooking it up to a Raspberry Pi

Sparkfun has also released a breakout board (SPX-14568) from their experimental SparkX labs. It uses their QWIIC connection system and also has a library for Arduino.

All the tutorials I've seen so far use a graphic display. But you could display the output on NeoPixels, on a servo-array or translate it into sounds. You could draw images with sparklers. Since you also have access to the raw data you could store time lapses. Combine this with traditional movement and distance sensors for more accurate navigation for your robots, or add another layer to your home security system. If you can code, you can create anything you want.

For less than $50 you get a useful sensor that's far more than a toy - definitely worth checking out for a wide variety of uses.

Wednesday, March 7, 2018

Comfort Food - An Abstract Concept

Comfort food means different things to different people. It might be a bowl of Mac-n-Cheese or a plate full of your grandmother's homemade cookies. It's an abstract concept, this comfort food, because "comfort" is such a subjective feeling.

I got to see a sick friend perk up and feel better after a stop at one of their favorite roadside diners - complete with original 70s era décor and an ambience of continuing after-school employment. This place is classic.

My friend's food choices might not have been what a doctor would have ordered for gastrointestinal distress (it involved chili, cheese and lots of fried items), but the positive affect of the food was undeniable.

The kind of place where "all the way" means mustard and ketchup - perhaps to match the bright original décor.

Or maybe it wasn't the food itself that had the positive affect. Maybe it was the childhood memories of family and friends and high-school escapes that helped my friend feel better.

Either way, there is still a place and a function for the few genuine roadside diners remaining in our landscapes. Adding some checkered tiles and reprinted posters might help a chain restaurant get more customers. But it's the real mom-and-pop ships, with the third generation of kids from the same families doing their stint at the register and fryer, that established that original emotional connection and still give the chain shops their meaning.

These old diners might not have a clever name for every burger variation (it's a hamburger with ???, not an outdated car brand) but the people at the register might know (because they know you) that extra mayo means a LOT of extra mayo, and they know to leave the fries in a little longer because you like them crisp.

I think that's what made my friend feel better, visiting with something unchanging and familiar when they were wondering if they were ever going to feel normal again. Just being in the diner and seeing it so eternal and unchanging confirmed that. yes, things would continue and some things can still be counted on.

BTW, I have no history or emotional connection to this place - I was just there for the food... but my fries were extra crispy, just like I like them.

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Sunday, March 4, 2018

Welded Washer Bowl - Flawed but Finished

Admit your faults and make the best of them. That's true for personalities and projects. I tried to make one of those spectacular bowls made out of welded washers and the project failed horribly because I have a flawed personality.

I have already described how I painted this bowl in a previous post. In that post I promised to "tell the story of my own idiocy." So here is my official, "I fail a lot too, so you have no real excuse not to try making things, we all fail, just do it" post for this month.

welded washer bowl fail
Good idea, bad execution - just add some spray paint.

I looked at how-to videos on YouTube and thought, "Hey, that's simple enough - I can do that." Well I couldn't do that, but I do have some legitimate reasons why this bowl isn't as pretty as the ones on Pinterest.

First, I only had a few hours of stick welding experience. They had taught me how to do horizontal, vertical and overhead tee-welds using the same thick stock and forgiving 7018 rods. We had about half of a class left free at the end of the short course and the teacher said we could do our own projects.

I had some washers that were too big to use in even my largest jewelry or other projects, so I said I wanted to make a washer bowl. The teacher advised against it but let me do it anyway, perhaps knowing that public failure after a strong warning is also a good teacher.

The teacher, a patient and skilled mentor, knew that I should wait until I had access to the MIG machines in the next round of classes. The YouTube videos also used MIG. But I could lay down a 6" multi-pass bead so obviously I could do anything.


The poor suffering teacher did the best he could, handed me some 6013s and warned me that they would sputter and splatter and be generally more fussy than the 7018s, especially on coated metal.

He also mentioned that the washers were much thinner than the stock we had been taught on, so I needed to be careful not to burn through the washers. He also warned that the washers were of various thicknesses, so joining thin to thick ones would be different than the single thickness plates I was used to. And he also noted that welding a tiny joining face would feel different than the solid metal plates we had practiced on.

Sure, sure.... dude I can lay down a bead 85% of the time and barely stick it on starting. I'm good to go.

He was right. I was wrong. The bowl sucks. I learned a lot.

First time welding metals of various thicknesses and sizes plus first time using 6013s gave... ummmmm... various levels of quality in the welds. You can see the results of my learning curve by comparing the upper right quadrant with the rest of the so-called bowl.

All I have to do is use the same speed and settings as I did on the thick plate stock, right? Wrong... I burned through most of the first few tries before I even knew I had a spark. These thin washers don't act anything like what I was used to.

Still not the prettiest welds, but at least I didn't burn away more metal than I deposited.

Everything the teacher warned me about turned out to be accurate. You can tell which part of the bowl I started with. It's the part with drippy holes where the weld should be. As I started adding more washers though, I realized I just needed to tack them, not lay down a bead.

Be quick with the stick young grasshopper.

So most of my welding problems turned out to be personality flaws. Luckily for me, I am also stubborn.

But I own spray paint, so all is not lost..

The bowl is way too ugly to use inside, not even worth grinding down. It will never grace the table at a dinner party where I casually say, "Why yes, thank you... but I didn't buy it... I made it myself in my first welding class." Nope, not gonna happen.

But maybe if I add enough coats of paint I can find a place for the so-called bowl in a remote corner of the yard.

So if it's not good enough to display in bare metal, maybe some spray paint will help hide the errors.

It's still not pretty enough for use inside, but maybe add some sphagnum and some ferns, set it outside, way back in the corner of the yard where no one ever walks.

If ivy is the best friend of bad architects, a large mass of ferns may become the best friend of a bad welder.

And just so you know, the teacher did come to look at the bowl and said, "Hmmm, that's not as bad as I thought it would be." He, of course, knew exactly where I started welding and where I started to understand just by looking at the welds. I think he was just happy that he had managed to teach me enough that I could learn from failures and adjust - not well, not fast - but still learn and adjust on the fly.

I might be an idiot, but the teacher is an extremely skilled welder and also a really good teacher. I also took the Intro to MIG class and learned a lot - both what I should do and, like this project, some things that I think should have worked but didn't.

I've made fun of myself a lot in this post. But I should point out that the teacher also helped me learn how to successfully weld basic components in a reasonably proficient way. Repetition, knowledge, examples, repetition and more repetition means that I can actually do some basic welds. I am grateful for his patience and help, his insistence that I stick to the basics until I could do them well, and then allowing me to fail in such a way that I learned WHY he insisted I do it a certain way to begin with.

Seeing the results of doing things both the right way and wrong way is good preparation for when I don't have an expert to ask before every weld - which should be very soon (hint).

And finally, to those five artist friends who keep talking about taking a welding class but never do (you know who you are) --- you see how bad I am at it and I've shared it in public. Now get over to the local community college or trade school and take the introductory class. It's cheap, it's fun and it's actually pretty easy if you follow directions.

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Thursday, March 1, 2018

Hack Your Game Controller - Part #1 the Teardown

Everybody dreams of hacking their game control pad and making it control something else. Maybe to run their RC car, a robotic arm, or maybe their home theater system.

Other folks need to mod their controller so they can use it better. Not everyone has full use of both hands, yet most game controllers require two hands. What if you want to reconfigure the buttons and place them elsewhere, or turn them into foot pedals.

Either way, the process of modding requires a medium level of electronic knowledge and some crafting skills. There are some good tutorials out there for hacking specific controller models to do specific things. That's great, but what if you don't have that specific controller. Or what if you want to do something different than the what the tutorial shows you.

I've seen too many people start modding their controllers and then stop because their model or their needs are too different from the tutorials. Also, I don't know of any good generic introductions to hacking and modding game controllers.

I was one of those people who gave up the first time I tried it, and it has taken me more than three years of tinkering with electronics to learn enough that I can take parts from multiple tutorials and mix them together to work with my controllers. Now it all seems so simple, not even worth writing a tutorial on.

But I recently saw another person starting the learning process and remembered how overwhelming it could be. So I thought I would do a series of simple videos to help get newbies started - to teach enough of the basic concepts so that they can pick out the useful parts from other how-to guides.

The first step is look inside some game controllers. Then poke around and notice the differences and similarities in various models. That's what this video does - we tear down three old game controllers and have a quick look around.

(Or go directly to the YouTube video on my channel)

Just cracking the case and looking around can be really scary for first timers. Having buttons and switches falling out, not really understanding how it all works, where the electrical signals come from or where they go - it can be overwhelming.

Remember back to when you didn't really understand the difference between digital and analog signals, and you didn't "just know" which components did what. That's who these first few videos are designed for. So be patient, the real fun stuff is coming up after we cover the basics.

In this video we salvage a few parts, just cut them right off the PCB and leave the wires dangling and unconnected. Savage!!! The next video will explore how to re-use the parts we scavenge in this video. We'll look at the buttons and the joysticks and get a better understanding of digital versus analog signals.

We'll even explore how we can hook these salvaged parts up to an Arduino microcontroller. And all these concepts will be useful if you want to simply relocate buttons using your existing controllers.

As the series grows I will make a project page. There is a lot of good information out there on modding game controllers, so as the concepts are introduced I will link to these videos and tutorials.

If a few of you crack the cases of your controllers and rip parts out to use elsewhere, then this video will be a success.

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Wednesday, February 28, 2018

3d Printed Door Handle Extension

Making useful and functional parts was a big reason for me getting a 3d printer. I made this door handle extension in a few minutes and thought it was such a good example of the power of 3d printing that I would share it.

3d printed door handle extension in Fusion 360

I know I post about a lot of fun 3d printed stuff ( like bikini tops or shadow casters or even jewelry ) but I also design a lot of stuff for everyday use. You know, the boring replacement knobs or obscure parts for outdated equipment. Most of the time I think it's so boring I don't bother to post about it.

After all, you can buy a new knob cheap, and who wants to spend three hours designing a replacement part for an almost dead power tool anyways? But people seem to like this project, maybe because it's a brand new object instead of a replacement part.

Check out the Instructables guide - I put all the details there. If you like this type of project then let me know and I'll post more useful (if somewhat more boring) projects with 3d printing.

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Sunday, February 25, 2018

My Cup Runneth Over - 3d Printed Bra v1

Support your local makers - I'm doing my part with this 3d printed bra. Yes, that's right... a custom bikini top bra cup designed in Fusion 360 and printed on a hobby level 3d printer.

Okay, so the project started as a hat. Think "fascinator" base or mesh ball-caps. I wanted to see how different types of French curves joined together when bent. I knew different curves could result in any shape from a cone to a perfect sphere, or onion domes to flattened rounded-corner cylinders. But I had never really designed something with a variable curving shape. Hats looked like a good item to test with. Little did I know.

So I started experimenting with curves and shapes and bending --- and voila, I had my first piece of 3d printed lingerie instead. It not only  turned out better than I expected, I decided a 3d printed bikini top is way more useful and fun than a hat anyways - pretty happy with this failure discovery.

3d printed heat formed mesh bikini bra cup
Bright pink bikini bra cup printed on a 3d printer and designed in Fusion 360. It's a bit of over designing, but it sure was fun.

I've been experimenting with heat-shaping 3d printed panels recently. Sure, I can print the model pre-shaped, an all in one standalone print. I could have easily printed this object pre-bent and ready to wear. But as I discovered when printing my mini-terrarium greenhouse, it's sometimes a lot quicker to print flat objects and assemble them.

My first experiment with heat-forming 3d-prints was a simple bowl made from a flat 3d-printed sheet, which turned out okay. Good enough that I wanted to try something more complex.

The bowl shaping experiment relied on the patterns within the perforations to allow deformation when heated. The corners in the pattern are arranged so that the surface can bend in three dimensions without significantly changing the structure. That technique worked fine, so I wanted to add a second variable to better control the shape.

I know a little about traditional pattern making for clothes. I also have some experience shaping and heat-forming foam panels into costumes and props for cosplay. So I figured heat shaping PLA wouldn't be that much different.

I also wanted to use this series of tests to better understand just how curves affect the final shape. I have Fusion 360 and Meshmixer and several other programs that could take the final shape and create a cutting pattern for me.

(I had to print a couple of quick failed experiments before I remembered that I needed to use those traditional pattern making skills though. Not always the smartest cookie on the shelf.)

But the software makes most of the decisions when I use those techniques, and I really wanted to understand how to do it manually. I think when I understand pattern making better I can probably force or at least suggest settings for the programs to give me better patterns.

This is the first experiment that gave me the smoothly varying curves I was after. It was a very simple pattern, but it was also the first time I used splines (aka French curves) instead of simple arcs. The result is a lot closer to a single, flowing shape and less like the segmented domes I got when I used simple arcs and lines.

That's when I decided to declare, "This is now officially a bra." Well, half a bra... okay just one cup. But still, it's a much more body-friendly form than anything I had created before.

3d printed heat formed mesh bikini bra cup

Also notice that the decorative-infill pattern is simple. It is NOT designed to flex and deform. That means this sheet of plastic reacts to bending in a manner very similar to that of paper or non-stretchy cloth. It's really just the way the two curves join that makes the final shape so much smoother.

If I combined the deformable-mesh technique from the bowl experiment with the spline-curve edges from this experiment, the plastic sheet should begin to behave more like cosplay-foam or stretchy cloth. Then... print it in flexible filament to actually make it comfortable to wear. That's the next phase of experiments.

And yes, there should be more experiments with 3d-printed fabric and clothing coming soon. But understanding the traditional methods of pattern making is still an essential skill. For instance, my 3d-printed chainmail is pretty flexible. But to get it to fit properly at any large scale, like a vest or corset, I will still need to create differently shaped pieces of the mail just like you would with old-fashioned cloth.

pattern for 3d printed heat formed mesh bikini bra cup
The pattern in Fusion 360. You can see the different types of curves on every edge. Sure, it's 3d, but the principles are the same as used in traditional clothing patterns.

So no matter which direction I go, I must get better at pattern making. Right now, I have my hands full just with this, but I can already tell it's going to be a fun journey.

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Tuesday, February 20, 2018

Four Seasons in February

Nature, my old and dear friend... what's up with you lately? I know it's the shortest month of the year, but do you really need to get all four seasons into 28 days?

A local pond showing all four seasons at the same time. The right half is still frozen solid at the shadow line of the trees. But the grass is beginning to green and there is a distinct pink tinge of fledgling buds on the tree. And as I walked the perimeter in shirt sleeves the ice cracked loudly as it settled. Don't get me wrong, I enjoyed the experience, but I don't know what to expect next.

First it was a deep cold that froze the lakes and streams. Then it was floods. Then some snow. And now we are expecting temperatures in the seventies.

And today you went from sun and a gentle breeze to thick fogs rolling for near zero visibility. I spend a lot of time outdoors enjoying your beauty, so I have clothing and gear for any of your looks.

But not knowing if I need ice cleats and hand-warmers or Bermuda shorts and flip-flops is kind of confusing me.

You know, never mind. I will just try to get out and visit you regularly and enjoy or time together. You do whatever you need to do and I'll find a way to discover the joy you provide.

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Friday, February 16, 2018

T-Shirt Haiku from DIY Scraps

Create poetry with up-cycled T-shirt scraps. Turn your old tees into one-of-a-kind works of individualized art.

Someone donated a bunch of old T-shirts for my (failed) attempt at making 3d printed templates. So I found myself with lot's of tees that didn't fit me/ I slashed a few in my experiments, but I still had lots left over/

I figured I could make a few hoods and scarves and pillows. But what could I do with all those free swag tee shirts from 2014? Too bad I couldn't just use elements from each of the designs and make something new.

Or wait... maybe I could. I do have scissors and I do have fabric glue. Heck, I even own a sewing machine if I wanted to get serious.

So I sat down with the scissors and a bag of old shirts during the Olympics and started cutting out words from the front and back of 20 shirts.

It was a perfect task. Unlike most of my hobbies I could start and stop with no ill effects. I didn't lose my train of thought, the tee didn't dry, crack, sag or over-process in any way.

I enjoyed the parts of the Olympics I wanted and the holes in the tee shirts stayed just as they were and when I came back I just started cutting again.

What I thought would be a tedious task turned out to be a lot of fun. In fact, I think it helped me enjoy the Olympic events even more.

Nervous about whether your fave is going to make it into semi-finals - well cut apart some tee shirts.

Your favorite might be getting knocked off the podium - make the cuts extra ragged. Heck the more ragged and nervous looking the better, just makes it look really hand made.

Of course making the scraps into a work of art is another story. Once I realized that I could never color coordinate or match sizes or fonts - well then it became fun again and I had some flashbacks to my teen tears and rebellious designing. Shew, this adulting in design thing had messed with my sense of freedom and spontaneity.

So this was a good, I got a sense of fun back, made something fun from discarded clothes, and even found a bright-sided silvered-lining to the filed craft-knife experiments. This was a fun win.

Of course my short poem writing skills had also atrophied. But I listened to some music, realized the lyrics actually made no sense and if they could do it then I could do it, I composed three amaze-balls poems in just a few minutes. And I think I got back with my teen self here as well.

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Saturday, February 10, 2018

What's Inside an Old Humidifier

What's inside an old ultrasonic humidifier, and is there anything worth salvaging? The short answer is YES, lot's of fun stuff in there.

Someone donated this old ultrasonic humidifier for us to tear down. I hoped we could get the speed control and maybe a fan out if it. But I didn't know if everything would be on a single PCB and therefore difficult to salvage. Luckily, all the main components were separate and the PCB only supplied the power.

So we wound up getting a bunch of good components that we can re-use. We also got some nifty tidbits that will be good for prop building. Check out the short video to see what we found...

It looks like the humidifier had gotten hit with a power surge. But this thing was sturdy and it still sort of worked, if very weakly. There was almost no mist or air coming out of it. Once we cracked the case we could see why. The surge had run in and fried the AC components. It's surprising that it still worked at all, but it made it easy for us to decide to salvage it instead of repairing it.

We tested the salvaged components and they all worked fine. My two favorites are:
  • An all-in-one power switch with speed control and LED indicator complete with housing
  • And a magnetic reed switch type sensor along with a floating circular trigger magnet.
Both of these still worked perfectly. We also got some nice heat-sinks, some JST connectors, a small cage fan and several oddly shaped items perfect for use in cosplay or prop building,

Knob and Controls
The speed control is perfect for an Arduino project. It has three completely separate circuits going into the same housing to control three functions. There's a high current circuit to the on/off switch, a mid current to potentiometer, and a light-duty circuit to the LED.

I also noticed that they were using the potentiometer more like what I think as a rheostat. Even though the potentiometer has three tabs, they were only using two. But the tabs are accessible, so we can always add the traditional third line of the circuit.

With this configuration, you can turn the project on, then control an analog input with a single knob. The LED can be pulsed or blinked to give visual feedback.

And it's in a great housing that's really easy to mount into any project. It's circular and flat, so no weird shapes and curves to match. Just cut a hole, a big hole, into any enclosure and you have a very nice control panel - sweet!

Water Level Sensor
My other favorite find was the magnetic reed switch and magnet combo. This sensor is already on a slim PCB with a handy JST connector. And the floating ring-magnet is already sized to trigger the switch.

That's going to make using this as a water level sensor so much easier. These sensors and magnets are cheap to buy, but configuring them can be a hassle. When they come pre-matched and sold for use in fountains the price goes way up. So to get these for free was a pleasant surprise.

Overall, I'm very happy with the haul from this old humidifier. And the video was fun to make so I might start recording more teardowns. We have a room full of donated items, a huge random collection of semi-junk to tear apart and explore - loads of fun for the whole family - and much better than experimenting with items that still work.

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Thursday, February 8, 2018

Making a 3d Printed Bowl with a Hairdryer

Fun 3d printed project with none of the technical hassles. People sometimes shy away from 3d printing because it looks so complicated. I wanted to make something simple that people could play with and easily customize, a little something that they could hold in their hands and shape with nothing but a hair dryer and some light pressure.

Plus, if people can touch it and control it, shape it with heat and get comfortable with the material, then they might be more interested in learning about 3d printing. It's not so scary once you realize it's just regular plastic that has been heated up until it can be bent and sculpted. That's why they call it "thermos plastic" after all.

Expando changoooo...  take a simple home hair dryer a to a thin PLA 3d print and you can shape it and bend it into any form you want. The best (and worst) of both worlds.

So you can see where the lines started to string and the lip got deformed, but that's mostly from a lack of control with the hair dryers.

I knew that thin 3d prints could be reshaped with a common hair dryer, so I designed a simple lattice that I could print really quickly.

I have played around with these types of lattice structures before. I've made them out of paper and craft-foam and even cloth. So I knew a few shapes and cutting patterns that expand nicely when they get deformed

I hoped that the 3d prints would expand and shape nicely, and more importantly, I hoped that they would hold there shape and remain sturdy once they cooled back down.

The paper and foam versions are fun to play with,  but they don't hold their shape when released. They collapse back into a flat sheet. It's fun to make accordion shapes that you can stretch and twist and bounce, but I wanted the lattice to keep it's shape.

So 3d printer plastic (specifically PLA) seemed like a good bet.

It started life as a flat sheet.

Then it got heated and pressed onto a sphere to deform the lattice.

And it worked really well. The PLA did stretch and expand much like the craft-foam, but it held it's shape perfectly when it cooled down.

There are some issues I want to work on. You'll notice that the print became "stringy" and the edges are warped. I printed the lattice so thin that the individual "print lines" acted as strings and I turned the hair dryer on high, so the strings became so flexible they actually got blown around by the air. I wanted them to separate and expand uniformly, not like a wild hair day. Even the edges got softened and deformed.

The fix should be easy. I can print the lattice thicker, I can use a lower heat and blower setting - or I can even put the lattice into a toaster oven and let it gently drape over a form from the force of gravity.

And I could make a simple frame to hold the edges so that they don't deform while the center of the lattice gets all rubbery and stretchy. Lots of ideas to play with.

This is just a simple bowl. But the same technique can be used to create jewelry like bracelets and necklaces. A more advanced maker could create hats and other fashion accessories. Those 3d printed arm and leg braces that you've seen, well they are often heat formed for the final fit.

And individual parts can be "welded" together to form larger pieces. So the brim and bowl of a hat could be printed separately, formed to the user's liking, then be combined into a finished hat.

More importantly, most people are comfortable drawing a flat 2d design. And they have bent various materials for years with their bare hands.

With this technique anyone can draw a simple 2d pattern, print it out in minutes, then heat form it into the shape they want. Once they do that, maybe they will want to start doing the same thing in 3d.

Just another way to gently introduce people to 3d design... muhahahaaaaa.

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Monday, February 5, 2018

DIY Solar Heater - It Really Works

I've read about these for years so I finally made one - and it works - 120F heated air within minutes of getting put into the sunlight. It's simple to make, easy to use, super rugged and best of all, it's almost completely free.

Basically, it's stacks of aluminum cans that have been painted black You punch a hole in each can so the air can circulate, then caulk them together into long tubes. Put the tubes into a box with a clear cover and insulation and you've got yourself a free solar heat collector.

Whoa, this thing is heating up quickly. I could feel the warm air rising up from the openings in the top of the cans and the thermometer confirmed it, Not bad for a stack of old aluminum cans.

I did the first few steps, made the tubes and spray painted them matte black, then stuck them in a window to test. I'm impressed enough with the results that I think I will make the box for them. The tubes heated up the air to at least 120 degrees in a few minutes. (Might be higher, but that's as high as my thermometer went.) The cans are just warm to the touch and the air rises gently from the openings in the top. So they're comfortable to the touch with no danger of burning or fire, yay.

The tutorials and associated forums have all kinds of details and suggestions to make these heat an entire house. The best type of glass for maximum light transmission, the correct hole size for best air flow, the best type and thickness of paints for maximum heat gain etc.

But I'm not going to cover an entire wall with these or heat my entire house, so I'm just going to improvise without much concern for maximizing efficiency. I have some speaker cabinets I gutted and some scratched plexiglas.  Perfect for a small experimental version.

I will probably just heat a small storage box with it or maybe create a warm place for the wandering neighborhood felines. I probably won't bother adding a fan or even a auto-closing vent since I'll just be letting some warm air into an otherwise unheated space.

This will be a good excuse to use up these scrap items, finally get them out of my way and make something that's actually useful all at the same time.

Like I said, I've known about these solar collectors for years. But I had always lived in warmer climates where cooling was more of a concern than heating. And buying the lumber and glass made it too expensive for a toy project (spend 20 to save 5).

Now, however, I have access to both cool weather and donations at the Maker Group. Suddenly, I have all kinds of materials at my disposal - too many sometimes, like "I need to clear out this entire room" quantities of scrap materials.

I do have some experiments I want to try. Does putting gravel inside the cans affect heat generation and retention? Do metal screens work just as well - there are tutorials that say they do. What about old floor tiles? I have half a box of broken tiles Can I paint them black and use them as collectors, or maybe use them to store the heat overnight.

Looks like we've got six more weeks of winter, so I've still got time to experiment.

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Thursday, February 1, 2018

Slash and Run - I Think I'm Done

I've slashed several tee-shirts over the last few days and I think I've finally gotten this whole 3d printed template idea out of my system. Can't really call it a success in traditional terms, but I found out a lot of things. More importantly, I squashed a nagging idea from years back that wouldn't go away until I actually tried it.

I seem to be writing more about this failed attempt than my more complex (and successful) projects. I will return to writing about the highly technical detailed successes soon, but I just felt like I needed to document a silly project once in while.

I think it's because I know there are other makers out there who do the same thing. We all do it, follow an impulse even though we know it might not be the smartest design choice. It's part of the creative process. So continue to play with useless things, make bad choices and try to fix them. Because somewhere underneath, there's a reason you are working this set of problems - sit back, buckle in and enjoy the ride.

Okay, so the template worked fine. But it definitely wasn't worth all the effort.

What did I learn from all this?:

The 3d printed templates did work, but they are more trouble than they are worth

Any time saved during cutting was destroyed in the printing process. If I saved two minutes per cut tee-shirt, I would have to do a lot of shirts to make up for the hour of printing time.

PLA can be cut with a craft blade, and it will get cut after a few uses. Every template got nicked. especially after I started thinking "Hey, I got the hang of this." Not good for high volume, speedy production work.

The "clamping action" derived from using a top and bottom plate didn't help at all. A single template on top worked just as well. At least I cut the printing time in half,

Using medium pressure and multiple strokes of the blade made the cleanest cuts. Trying to cut the cloth in one pass only worked with the sharpest, newest blades - and then only sometimes. It was more likely to drag the cloth instead of cutting all the way through.

The cloth dragged and stretched even when I had a slot in the bottom plate. I had hoped I could puncture the fabric and slice quickly the rest of the length. It didn't work, slashing with the edge of the blade wasn't any more effective than overly forceful use of the blade tip.

Any line shorter than an inch reads as a hole, not a slash. Tiny, intricate patterns just looked like there were a bunch of random holes.

Any slashes closer than 10mm looked like strings. Using 20-50mm spacing made it look more like what I wanted.

Well that clean precision look didn't last very long did it?

Got reminded that tee-shirt material stretches quickly and the clean cuts I made quickly turned into a blobby mess after a short wearing. All that work for five minutes of precisely cut look - then it turned into a tangled mess.

Got reminded that simple slashed in denim jeans are not very effective decorations. Denim does hold the shape of the cuts, so you need to cut an "opening" instead of a simple slash if you want the pattern to be seen. The slits might open up enough to be seen after  a few days of wearing or a good washing or two. But actually cutting sections out to make larger holes worked much better.

After all this designing and printing and testing I arrived at some conclusions:

Cutting the templates with a laser-cutter or CNC would be much quicker and, using chipboard or metal, would result in a sturdier product. I knew this already, but I only have a 3d printer, so I used it.

Maybe I don't need a template at all. I thought it would save me time and it did, but a minute a shirt isn't that significant.

No-one cares about perfectly spaced and cleanly cut lines for the level of designs these templates create. These are simple shapes, not complex lace patterns. And the cloth distorts so quickly the improvement disappears after a few minutes.

Just use a pair of good scissors or get a rotary cutter. They will work just as well as the templating system did for designs that are  this simple.

So was this a failure? Absolutely! I wasted several hours going down the wrong path. And worse yet, I knew it was the wrong path when I started. So why did I do it? Well, history I guess.

Like I said before, I had tried cutting tee-shirts when I was much younger and I didn't like the results. They were sloppy and ragged. I wanted clean, precise cuts. I kept thinking, "If I could only create template it would be much easier."

That idea stuck with me for years, so when I got a 3d printer I decided to try it. I tried it even though I knew a laser cutter or CBC would be a better solution, and even though desktop laser cutters are cheap these days.

I even knew that the cheap scissors I used back then were not appropriate for cloth. Now I own good scissors and can easily make clean cuts in any cloth.

And these days, there are the new rotary cutters that slice through several layers of cloth so cleanly and easily even I can do it.

But you must understand, I had once had an "IDEA" and that thing had stuck in my head for a decade or more. I must bring it out into the open and battle it on the physical level or it would always be bouncing around in my brain taking up space and time that could be used for something useful.

So I did it.

Now I can rest.

So no, this exercise wasn't a failure at all. It was a necessary step for a certain type of warped designer-mind. I won, I killed the silly notion and I have proof of my victory It was a lot of work, but now I can move on to other ideas.

It wasn't a brick wall, it was just a reflection of something else.

And the project wasn't a total loss. I got some other ideas during the process. One involves open flame torches, metal plates and old jeans. Another involves heat bending flat 3d shapes. If either idea works like I hope, evenly a little, I will share the results.

My final thought - get a frikkin laser cutter if you want to do this kind of stuff - that's what they are made for and why they've become so popular. Slap a tee-shirt on the platter and cut out any shape you want in a matter of seconds. If you want to do a lot of tee-shirt and other clothing modifications, invest in the equipment best suited for it. 

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Sunday, January 21, 2018

Good Enough to Start With - Cut and Run

I got something right on the first try, then spent a full day trying and failing to make it better - only to realize it didn't really need to be improved. But like most dead ends, I learned a lot of useful stuff along the way.

Last week I posted about a 3d printed template for cutting, slashing and modifying fabric. The design was a success, both because it was easy to customize and print new designs with only a few minutes work for each pattern, and because it actually helped making clean straight cuts in tee-shirts.

Not satisfied, I continued to think of new ways to use this approach until I reached the limits of the first design. I wanted bigger better, smaller faster, simpler yet more complex designs. Are you beginning to suspect I might have gotten carried away?

Sure, the template worked. But I noticed that any design with the slots closer than about 10mm started to create problems. Common tee-shirt fabric, being all stretchy and flimsy, was particularly problematic. It would stretch, gather and distort when the cutting slots got too close together. This really sucked because slashing old tee-shirts was the original impetus behind the entire concept.

I also noticed that very thin or slippery fabrics like sateen, or very thick fabrics like denim didn't always work very well. If I was careful, I could do both. But I had to take care to hold the template just right and position and lay out the fabric correctly.

A simple, first try success wasn't good enough. I had to make it better. I had a serious case of designer fever.

What I needed were some cleats or ridges and matching grooves to really clamp down on the cloth and hold it in place.

So I started a redesign of the entire template system. I spent half of a day thinking about it and drawing simple sketches. What if I put cleats or ridges on the surfaces, maybe add matching indentations to really clinch the cloth and keep it from moving.

I did several sketches like that. I got a feel for a way to draw the "features" easily. And then started thinking about how to automate the process so that I could type in a few numbers and the pattern would magically draw itself.

The first (successful) version simply extruded shapes up from the ground plane, the cut or joined the shapes to create two slotted plates. But this new cleated, wavy system wouldn't work like that. Now, I had to extrude on two or even three planes and somehow coordinate the origins and geometries across multiple drawing steps.

That was kind of annoying. I had to redo all my old work/ And, because I wasn't sure which, if any. of the new shapes would work, I  needed to find the simplest method of automating multiple styles of cleats and clips and waves.

I couldn't find any one style that worked for all shapes, so I wound up generating several different files with completely different automation strategies.

Getting a flat face to match with another flat face is easy. getting curved and notched faces to mate with other curved faces with varying distances between them, well that isn't nearly as easy. Especially if the surfaces curve in all directions at once.

Automating that process is even harder. Boy did I learn a lot.

Or what if I made the entire surface wavy - yeah, that would really lock them together.

I spent about a full day concepting then drawing and automating these new designs. I was getting closer, but also getting frustrated. Then I went back to look at the results from the first tests and realized something.

I didn't need to do all this.

Seriously, I'm never going to be cutting two hundred strips of cloth that are only 2mm wide. That's just ridiculous. Look at any example of slashed tee-shirt mods. They have a few (10-20) cuts and the strips are at least an inch wide, not a hundred tiny cuts.

This project was supposed to be about slapping down a template on a worn out tee and making 10 or 20 relatively straight cuts in a few seconds.

I had gotten carried away and was trying to create a process that would rival the precision of a laser cutter. Why do that?

So I stopped the design and tried to feel better about the day I had just lost to stupidity. It was probably the easiest part of the day. I did actually learn a lot, and any time you find new ways of doing things it's a win. If not today, then sometime soon.

There are parts that I can still use in this design. I can use some of the new ideas in other projects. I'm working on a metal and paper embosser where these techniques are useful. A lot of these ideas are also applicable for sliding joints for lids and cases. And this exploration helped me get a better grasp on basing multi-plane geometries off a single origin point.

So like most failures, I got a lot of useful information to use. So maybe that day wasn't a complete loss after all. Now I'm off to cut up more old shirts.

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