Thank you for voting / Ponoko test fit pieces!

First – a big thank you to everyone who voted for me in the sparkfun / ponoko / Geekdad contestI won!

From here on out I will be documenting my process as I go from rough prototype to finished laser cut beer vending machine!

There will be an upcoming longer piece on how to design for laser cutting. I have been amazed as to how many variables you need to keep in your head, and I haven’t even gotten the pieces yet! It seems like once you get it all figured out it is very systematic, but my design wasn’t nearly as tight as it needed to be in order to be laser cut.

This post is all about prep work. I have been talking with Josh at ponoko, and he suggested that I cut a few test pieces to figure some things out. I am planning on using t-bolt assembly. The good thing about that is that it ought to withstand both the thermal rigors of being refrigerated and the physical stress of having 12 oz cans banging around in the machine. The bad thing is that it adds another unknown to the design. I decided to test a bunch of different slot and tab widths to find one that fits as close to perfect as possible.

One interesting thing about designing for laser cutting is that you can easily control the cut dimensions within 0.1mm, but you don’t have any control over the thickness of the acrylic. Due to variances in manufacturing, the 3mm sheet could be +_ 15%! On a 3mm sheet your thickness could be off by up to 0.4mm. This means that for a tab and a slot, you have to make the short sides precise, and the wide sides a bit sloppy. Definitely an interesting twist.
hit the jump for more laser-cut plastic action!

Missed out on Sparkfun free day? Buy it anyways!



So, like many of my readers I spent the morning watching firefox time out on sparkfun’s website. Eventually the clouds parted just in time for me to see the ticker go from 70k to 98k, to 100k. Just like that the first ever (annual?) sparkfun free day was over. I was bummed. Then I started thinking about it. Everything in my cart was something I wanted, and I did have a good time this morning, and I had a good time thinking about what I was going to get, and why. I have always thought sparkfun is a really cool company, and the fact that I can’t get this stuff for free isn’t going to stop me from buying it.


Right now there are probably a few thousand people still crashing the gates of sparkfun.com trying to get in on free day. It is over. They rewarded us with the chance to get free stuff. I personally am going to thank them by buying it anyways.


Thanks Nate, thanks Sparkfun!

Christmas gifts for geeks (pt 4) Arduino Edition

Christmas_lights

arduino Bare Bones Board Macro

Introduction - just in case you haven’t renewed your geek card for the past year (decade?) Arduino is a term that refers to a microcontroller on a board that has certain hardware and software ‘shortcuts’ figured out. It was designed to be as plug and play as possible, and to lower the barrier to entry for people who want to let their computer interact with the physical world. The programming language is fairly simple and very well documented, and it is a matter of minutes between installing the software and uploading your first program! Like I usually do, there is an amazon store here in case you don’t want to read my witty banter.

arduino – the meat and potatoes of this whole shebang.
The cool thing about arduinos are that even if you already have one, you canalways find a use for another! You can set them up to ‘talk’ to each other. You can leave a project set up after finishing it, or be able to prototype multiple projects at the same time. Also, there are a wide array of shapes and sizes (and prices) of arduinos, and each one is suited for a different application.

arduino

You can start out with the ‘classic’ Duemilanove. It is the original form factor, and most of the shields are built to fit this one. This is a great one to use for prototyping, and if need be you can use a smaller board in your finished project. If this is your first arduino I would recommend getting the kit which includes jumper wires, a breadboard, some LEDs, resistors and a pushbutton. That way you can start making things blink as soon as you get it out of the box!

arduino mega
MEGA - The arduino mega is just like the Duemilanove except that it uses a bigger chip, is a bigger board, and has more inputs and outputs. Most of the code is portable across the two. If you have a project that needs more i/o’s than the smaller chips, then this is right up your alley!

Click the link to check out the good stuff! Continue reading

Christmas Gifts for Geeks (pt 3) MAKE magazine

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make-magazine

There really are few magazines that I eagerly look forward to. There are even fewer that I can’t hold back from reading in the bookstore BEFORE my subscription arrives (I just can’t hold back!) MAKE is chock full of cool projects, ideas, and people. They have detailed build plans for some of their projects, and they are always a source of inspiration. To give a gift subscription click here of just go to http://www.makezine.com/ There seem to be a few different deals out there. Sometimes you can get a makers notebook for free, and sometimes you can get an extra issue. You get to pick your deal.


It should also be noted that their blog is one of my main interests on the internet. You can find it at http://blog.makezine.com/ and it is almost like a new issue that arrives every time you hit the refresh button!


Make seems to be about celebrating the unabashed love of technology, and I unabashedly love that. If you know of someone who might like it – get it for them. If you already get it – loan out a few copies to your friends. This magazine deserves some more evangelism!

CD robot V 2.0! Adding serial control to an old scsi cd duplicator.

My newest project involves reincarnating a very old (1998) cd duplicating robot. It is a DTP-1000 that was originally SCSI only. Due to the fates smiling down upon me I was able to pick it up on ebay for $11. I bought it intending to put an arduino in the place of the control board and probably have to do a lot of reverse engineering. The next day I happened upon this site where, amazingly someone has already opened one of these up and has instructions on how to enable serial control! I still am in awe of how lucky I got and really happy that DarkBane dropped all of that knowledge on the world.

There are a lot of pics below, since that was the one thing I could do to add to the fine directions DarkBane has already provided. Another thing is that in his command set he has two typos. I will quote his post after the pix and note the command set in bold.

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“Arduino Powered” CD Changing Robot

UPDATE!

Check out my new(er) cd robot project here. I grabbed an old scsi changer machine from ebay and have been working on adding serial connectivity to it. If it works, it will be a much simpler route!

One of my “always in my head” projects is a CD changing machine. I have seen the myriad of other projects out there, and this always captivates me, in that it is just out of reach, but it seems to be a fairly simple concept. I have been thinking and sketching on this one for SUCH a long time that I have decided to post it before it is fully polished up.

arduino powered cd robot - left side

The basic premise is I have an arm that swings up and down mounted on a platform that rotates 180 degrees. Both of those are positioned by hobby servos. On the tip of the arm there is two vacuum aided suction cups and some hdpe tubing.

arduino powered cd robot - front view facing right

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7 questions for my avid fans

Seeing as how I am constantly inundated by media requests – I figured I would use my podium here to ask the readers a few questions. I look at it as distributed googling really, and hopefully finding some vetted answers in the sea of confusion that is out there.


1) has anyone used CHDK here? It is a modified firmware for certain cameras, and seemingly it allows you to get very low level access to the camera. With it you can enable time lapse mode, Raw shooting, video, motion detection, and I think they are working on time travel. This seems like an amazing project. Does anyone have any success with it? Does anyone have any recommendations on cameras? Im kind of looking at the SD1100 and the SD600.

and lastly, does anyone have any recommendations on where to find said camera cheaply? I’m running dd-wrt on my home router and have a hacked xbox, so this seems like it is within my reach, just looking for people with experience in it.


chdk interface

chdk interface


2) does anyone know of any good anti flicker plugins for after effects (or anything else (on a mac)) that will remove the frame-to-frame luminance variations of a dslr time lapse?


3) does anyone know why frame-to-frame luminance variations happen on my d40 running in complete darkness with a manual lens and a flash?


4) does anyone know of a good guide to moving an arduino project towards a mass producible item? Lets say I would like to make a one board version of my arduino rss reader – how would I go about doing that?


breadboard arduino

breadboard arduino


5) How much does the average human heart weigh?


6) Does anyone know of a comparison between the online stock video sites from a submitter’s perspective? Does anyone have experience with any specific sites? (feel free to email me if you would rather not post publicly – “r” at this domain, no prefix.)


7) Enough about me – Why are you here? What kinds of projects brought you here, and what kinds of projects would you like to see here?


Thanks for your time, and hopefully your answers!

gmail notifier project (for dummies)

I’ve been really interested in doing J4mie’s Physical Gmail Notifier ever since it came out in February. I only recently dropped into the project and got to learn a lot about python, plists, and arduino auto-reset functionality. I’m going to share what I’ve learned because I think there are lots of other people out there struggling to make it work. This page doesn’t really offer much that J4mie didn’t already say – it just says it in a different way.

I’ll post the code below – one issue with the way J4mie posted his was that it appended line numbers to everything and messed with formatting. Python is _really_ picky about formatting! All of the files are zipped HERE. It consists of three documents –

1) one python script that logs into your gmail rss feed and checks your total number of new messages. It then sends either an ‘m’ or an ‘n’ to the serial port.

2) one arduino sketch that tells the arduino to turn on or off a light based on the serial input

3) one .plist file that tells your mac (sorry pcs!) to run the python script every 60 seconds. If you run windows or linux then I’m sure there is something you can do to schedule this. You could also just set it to loop until quit. (to quit a script in terminal hit control-c)

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DIY CNC router build update

It’s been quite a while since my router arrived in the mail. It came in mid winter and essentially stopped all cnc progress. It was much heavier than I had expected, and the gantry I had built wasn’t up to the task. The x and y axes were finished, but needed to be rebuilt stronger. The last few weeks has seen the end of summer weather and the return of my tinkering productivity. I have put in a ton of time thinking, cutting and swearing in my garage.

DIY CNC router as it stands

DIY CNC router as it stands

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Lego NXT vs Arduino

battle of the microcontrollersI have always been interested in Lego NXT. It seems like a really easy way to get into robotics, and programming. I have never really figured out how functional it is in the “real world” (whatever that means)
The other day a coworker was really pushing the idea on me telling me I needed to buy a kit because it was so easy to build things. Now I really struggle with the arduino most of the time, but I enjoy the struggle, and I know that if I ultimately build something then I can replicate it fairly cheaply. That is my issue with NXT. It is REALLY expensive. It is expensive for legos, it is expensive for a microprocessor, and it is expensive for the peripherals. I think I’m past the target age of these things, but regardless, I priced out how much it would cost for me to “replicate” an NXT kit with and arduino.

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