Author Archive

Chicago’s Inaugural Group Telepresence Experimentation Event

This weekend, starting Friday May 23 at 8pm and continuing until Sunday May 25 at noon, Chicago will have its very first TeleHackathon.

Join the members of Pumping Station: One and South Side Hackerspace: Chicago in connecting our respective spaces in innovative, ridiculous and primarily useless ways. Imagine a lamp in one building with no apparent switch – yet it toggles on and off at random. That’s because it’s an IP lamp! The switch is at the other hackerspace!

Almost, but not entirely unlike, this!

Come out for the whole thing or a few hours, we’d love to see you here (or there! It’s the internet!) Make a thing talk to another thing that’s somewhere else, learn about internet communications, or just get your hack on. See you there!

 

-Derek

19

05 2014

Mini Maker Faire – or “How I annoyed hundreds of people”

On March 26th, our PR director forwarded an email to one of our mailing lists. This email detailed the Chicago Northside Mini Maker Faire, which was to happen in a little over a month. I decided that PS:1 needed to have a presence there, and it couldn’t just be a booth with some folks sitting behind it talking about hackerspaces all day.  An electronic project was very much within my skillset, but I didn’t want it to become yet another ‘how to solder’ class — they had one or two of those already. I wanted something that could be assembled quickly and offered a chance to talk about electronics if the assembler was interested. If they weren’t, they should have a fun doodad to walk away with.

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The final revision of the board art

I needed a project, something that would engage kids and adults. Something that was easy to assemble, cheap and offered a chance to learn a little bit about electronics (but didn’t require it!). I recalled a field trip I went on in high school. We went to an engineering firm or something, and they had us assemble little crystal radios on card stock. There were just four components that twisted together on the back, then you hooked up the crystal earset and bam! crappy radio.  I settled on a crappy optical theremin – using a photoresistor to modulate the pitch of a buzzer.2014-04-27 20.28.52 Thinking about it, I decided I could probably manage something pretty cool with five components or less if I used a microcontroller of some sort. I settled on the Atmel ATTiny45, which is an AVR in an 8 pin DIP package. Some clever folks have already ported the Arduino libraries to work on these small chips, so all I had to do was come up with a design and write a few lines of code. I won’t bore you with excessive details, you can check out the github repo.

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I had a number of parents and teachers assemble kits, too.

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Justin helping someone out

I learned a lot with this project, and  I think some other people did too. I had kids as young as 5 assemble these boards with guidance, some of them with surprisingly little help. Everyone seemed to like them, and I ran out of components for kits. I’m calling it a huge success, and I hope that this project is replicated and taken to other faires, expos and ‘learn electronics’ nights.   –Derek

08

05 2014

Mini Maker Faire in Chicago at Schurz High School – May 3

Reserve your spot to the third annual Chicago Northside Mini Maker Faire! Tickets are FREE to the public, but by reserving early you guarantee your spot. Now you can e-sign the media release on Eventbrite and skip the line! As always, your generous donations allow those who cannot otherwise afford Maker Faire to attend for free. Recommended donations are $10/adult, and $5/child under 12.

http://www.eventbrite.com/e/chicago-northside-mini-maker-faire-2014-tickets-10903088431

Pumping Station: One will hopefully be there with a table. Come visit us!

 

–Derek

10

04 2014

Caught in the Shop

I was walking through the shop tonight and saw something awesome happening. I took some crappy photos to show you (and I’m not sorry about it!).

That's a big piece of metal

Our Cold Metals area host, Mike, holding a big piece of metal. He’s going to turn it into a smaller piece of metal.

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Mike and Dean work on centering the piece.

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This is the part they’re trying to reproduce. This is a pulley for our new(ish) Johnson horizontal band saw. You’ll note that it’s bent. It’s also incorrectly sized, so there’s a bushing that’s been inserted that you can’t see. This bushing has no key, so the pulley was fairly noisy and inefficient.

 

 

25

03 2014

Adding digital speed indication to a drill press.

There’s a big bin of 5 digit, 7-segment displays sitting in our electronics lab. It’s the sort of thing that cries out for a project. I found one that’s the perfect shape for a digital speed readout for our big drill press, whose mechanical RPM indicator was broken.

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Testing out the display PCB. It’s got 3 16 bit shift registers.

The display was pretty simple to reverse-engineer. There’s a header on the back that’s connected directly to the relevant pins on the first shift register. Apply power, fire up a basic sketch built around shiftOut(), and away we go.

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My test rig, showing that the RPMs pretty close.

My code (patches welcome!) is not terribly complex. Basically I use a Hall effect sensor to trigger an interrupt every time a magnet glued to a wheel in the drill press passes. The time between interrupts is used to calculate RPM.

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Magnet + Hall effect sensor.

All told, I spent maybe four or five hours on this project. It’s probably the simplest possible solution to the problem, and my total investment is less than $10 in parts. And we’ve got an accurate readout of the speed of this big drill press.

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Complete system.

I’m out

-loans

13

03 2014

3D Printed Replacement Parts

Our shop has a few Black & Decker drills. They’re not contractor grade tools by any means. I was using one the other day for a project, and as I was walking back to the tool crib to put stuff away I was idly clicking the drive direction switch back and forth, as one does with a drill. I heard a snapping noise and the button now moved freely, no longer engaging the electrical switch responsible for direction reversal. Bummer. I figured I’d pop it open and see if I could repair it.

B&D Drill

The drill in question

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The factory part that broke. Note the distressed, white plastic at the bottom center.

The issue was a small plastic pin that engaged a switch with a matching cutout. Not a very complex mechanism. I drew the part up in Sketchup:

drill-fix

 

I skipped the nicely radiused leading edge, but this part is otherwise dimensionally similar to the factory piece. My initial attempts to use an entirely 3d-printed part failed, as the ~3mm pin was just not large enough to get a sturdy printed feature. I decided to drill it out and use a #2 screw to replace the pin. This one should outlast the rest of the drill.

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At this point you might be wondering why I didn’t do that with the original part to begin with, and that’s valid. My only answer is, “Because I didn’t think of it.”

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The part’s installed, and the drill is back in the tool crib.

It’s a simple result, but it’s the sort of thing I love about 3D printing.

-Derek

 

07

01 2014

Silicon ReSEMblance

Every year, the UIUC chapter of ACM has an student-run conference called Reflections|Projections . One (rather excellent) speaker at the 2013 conference was the well-spoken (and wickedly-smart) Todd Fernandez , who spoke about the state of the semiconductor integrated circuit industry. As a nice bonus for those brave souls who asked, or answered, a question during his talk, he was giving out junked silicon wafers. Not being much of a brave soul myself, but realizing that the wafer would make for an awesome sample in our now-functioning Scanning Electron Microscope (SEM), I answered a question about Moore’s Law and scored a wafer.

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Here’s a picture of a similar wafer we had on hand (Not the one we put in the SEM. We shattered that one.)

Saving you a trip to Wikipedia: the wafers are slices of an impressively large and pure single crystal of silicon (known as a boule) on which semiconductor devices (such as transistors) are fabricated. These devices are usually incredibly tiny and incredibly numerous.

What happens after that is that the SEM rasters a beam of electrons across the surface of the wafer sample and, in this particular case, utilizes its ability to detect secondary electrons kicked off the wafer by the beam. Because the surface is the important part and because the SEM’s resolution is so amazing, before we mounted the sample, we had to sterilize it in an acetone bath suspended in the space’s ultrasonic cleaner.

 

Now the cool part. Because, if you look at the picture below, you can easily see leads on the wafer that are 4 microns in width (and resolve gaps between the leads that are 2 microns wide). For reference’s sake, the diameter of a human hair is given as 100 microns on average. And that is awesome.

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Many thanks to the exceptional Ryan Pierce, who helped me with this every step of the way.

 

-Jerry Lebedowych

22

11 2013

A 3D Printed Pinhole Camera

It started simply. On October 3rd, I tabbed over to XChat and saw a highlight waiting for me:

<NegativeK> loans: http://www.thingiverse.com/thing:143882

Clicking the link took me to a Thingiverse page for a pinhole camera.

<loans> NegativeK: why am I not printing that right now

<NegativeK> Print that camera, loans, and I’ll share some dev kit and chemistry

So it started. Over the next week or so I spent some amount of time in front of the Lulzbot, coaxing the camera into existence. The prints all went fairly well, with no catastrophic issues. I had to print a body, a filmholder carrier, tripod mounts and shutter parts, and a ‘lens’ tube. I’d estimate it was less than 10 hours of printing, all told. I assembled the camera using with ABS slurry and fasteners, only needing to do a little bit of touch-up here and there to get everything fitted. I tested for light-tightness in a dark room with an LED flashlight. I made a pinhole out of some aluminum cut from a soda can. I took a stab at the ‘dimple and sand’ technique, though I think it’s something that will take some practice.

PINH5AD and shutter parts

The body/lens combo, shutter parts and tripod mount.

Shutter assembly

The completed shutter assembly.

Now I had a mostly-finished camera. The last ingredient was to be some adhesive-backed velvet, which would act as the gasket material. Someone (Everett), however, couldn’t wait. So on Sunday the 13th, we loaded up some film holders and cobbled something together in true hackerspace fashion.

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Don’t judge me. Then we carried the mess out into the alley, because we wanted to minimize exposure time. We set up to take a picture of our rollup door, because what else is out there?

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Metering was accomplished with a DSLR and a piece of scratch paper. This camera’s ‘lens’ is f/225 and the film was ISO400. We calculated a 12 second exposure time. We double checked everything, pulled the dark slide out, prepared a timer on a cell phone. Then we hit go and opened the shutter. Twelve long seconds went by, I was sure I was ruining the photo by shaking the camera  with the hand that was operating the shutter. Then the phone beeped, the shutter closed, and we were done.

Not being the sort to waste time, we quickly moved into the processing phase. I haven’t developed film since a high school photography class, but Everett was ready to go. It went down at the shop sink (In the newly cleared hot metals area), and soon enough we had our exposure. The negative looked good. Surprisingly good. Scanned with a DSLR, we had our photo:

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It isn’t perfect, but it’s a result. It’s even a reasonably well-exposed result, considering. The camera will benefit from a more precisely manufactured pinhole.

Our next goal is to try some exposures on positive paper, which is a process that gives you a print directly. The downside (maybe not?) is that it will be an hours-long exposure. We’ll see how it turns out.

 Until next time, hackers. -Derek

20

10 2013