Shmoocon 2012, 757 Labs and Harbor Freight
Last weekend was quite exciting, as a few members of 757 Labs built a project for Shmoocon. It was an audience feedback moose that took feedback via an internet website and visually (then audibly) responded. The eyes were BlinkM LEDs and the audio feedback was done by means of a Harbor Freight airhorn kit powered by ham radio power supplies.
Of course, being a con project, it was a bit last minute. Planning and software started much earlier, but it's just how things go. One huge last minute issue was when a relay failed. This relay was supplied with the Harbor Freight airhorn kit, and was used to switch the high current load of the compressor by means of the the microcontroller which was triggering the relay by means of a MOSFET.
After only a few tests the relay seemed to fail. One would guess the transistor failed, given that it's a 40 amp automotive relay. This failure, however, seemed to echo some online comments about the air horn kit.
Before heading to Radio Shack, I popped the top on one of the relays and low and behold, it's a lie. The 40 amp relay is really a fake case on a 5 amp relay. It was purposely made to look like it was a heavy duty 40 amp automotive relay, when it is not! I've heard about Chinese vendors doing this with capacitors, but never have witnessed it in real life. So here you have it, the 40 amp relay included with the Harbor Freight air horn kit is a lie.
The fix was ultimately to go to Radio Shack and pick up some replacement relays. A few taxicabs and a few Radio Shacks later relays that looked pretty similar to the Harbor Freight ones were in hand, but the Radio Shack ones weighed quite a bit more. We had 3 of the air horn kits, and sourced 3 replacement relays. The air horns draw at least 20 amps, so there is no way the supplied 5 amp relay (mocked up to look like a 40 amp relay) would last very long.
Relays before removal of cover. "40 Amp automotive relay":
Relays after removal of cover. It's really a 5 Amp PCB mount relay:
Unfortunately this delayed the airhorns until mid-day Saturday, as the Radio Shack nearby in the city closed early.
I wonder if Harbor Freight knows their supplier is lying to them?
Circuit Board Creation – First For The Lab
Members of the lab have finally started creating custom circuit boards for projects. The first is a custom board based on the electronics done for last year's high altitude balloon launch. The purpose of the board is for this year's entry into the Hackerspaces in Space high altitude balloon contest.
It took numerous tries, but progress has come around! More information to come once the board is fully populated.
Currently we're using the technique of transferring toner to a glossy surface, then ironing it onto the copper PCB surface, then etching with cupric chloride or ferric chloride.
iRobot iCreate-Based Robot Project
Jamie is working on building a ROS-based robot that looks pretty exciting. It's an open source robot which, once assembled, offers a good starting point for software creation. It uses a Microsoft Kinect, a netbook, and a iCreate (based on the Roomba vacuum cleaner).
Angus of Hines Design Labs cut the acrylic on his laser cutter as it's larger than the lab's. More info to follow on this neat project!
First 757 Labs Hackerspace Passport Stamp Granted!
Mitch Altman of the hackerspace Noisebridge in San Francisco made a large quantity of Hackerspace Passports and has been selling them at a remarkably low price. These neat little passports were created with the idea that hackerspaces could create stamps for them, and stamp the passports of visitors that come to their space.
On Saturday October the 22nd, 757 Labs had two visitors from the HacDc hackerspace in Washington, DC. ITechGeek and HaxWithAxe arrived around midnight after visiting the Fredricksburg, VA hackerspace. The good news is our members created a temporary stamp by laser etching wood and acrylic. The acrylic didn't absorb the ink well enough, but the wood version did the trick! ITechGeek is the first visitor to 757 Labs to receive a hackerspace passport stamp and 757 Labs is the first stamp in his passport. While the physical stamp is beta, it's the permanent design of our stamp.
Some great news is that Angus has cut the design on his engraver in real stamp rubber. He also improved the second layer stamp which wasn't ready yet, but is to be stamped in UV ink.
In the past, 757 Labs has welcomed visitors from Houston's TX/RX Labs, Freeside Atlanta, All Hands Active in Ann Arbor Michigan, The Cowtown Computer Congress in Kansas City, one visitor from the Netherlands, HacDC, and most likely some others. If you're coming to the area, feel free to drop us an email, jump on the public mailing list (link is over on the right), or join #hackerspace on irc.757.org to catch someone. We can easily accommodate any time/day.
In the future, for those participating with the hackerspace passports, we'll have stamps for you!
Solar Boiler Update
I've gone through quite a few iterations of the solar boiler. The current version uses a 47" Fresnel lens to focus sunlight down to about 1 square inch. The sunlight will focus on an evacuated tube that will transfer the heat into water. The aim is to boil the water and turn a steam engine, ultimately turning a motor and feeding clean energy into the grid. The solar boiler can now pivot in two dimensions allowing it the ability to track the sun as it moves from east to west from the morning until the evening and from north to south as the sun moves between winter and summer. The next step is to build in the tracking system which will consist of two stepper motors that will turn screws pivoting each of the two dimensions to follow the sun. We'll then tie in an MCU attached to some photocells to track the movement of the sun. After the tracker is built the boiler section is next. Honestly, I'm a little nervous about pressurizing steam. That episode of the mythbusters where they blew up the water heater has me a little on edge.
A Long Cray Supercomputer Weekend
Some more progress was made on getting the Cray J932SE supercomputer running at the lab. Using information from the logs of the friendly people at Cray-Cyber and doing some hacking on our own, we made it through part of the install process that hasn't been reached before. That is the good news. The bad news is there is a program or two missing from the Sun Workstation that appears to be required to actually install the UNICOS operating system on the computer. Feelers are out on the Internet and hopefully we will figure it out soon! Stay tuned.
Finalizing the Laser Engraver
VaShadow jumped in and pushed the laser engraver project ahead and now it's near completion. When we left off, Vex had completed the embedded controller that handles the pulse width modulation of the CO2 laser. Thanks to VaShadow, the engraver is now nearly encased in a box setup to keep the work area clear and push any bad smells out of the lab. TJ cut the metal that lines the inside of the box around the laser bounce area. The box is adapted from the original Meistergram layout and includes some needed adjustments.
Chances are it will be running again today, only this time with a nice safe enclosure! Many thanks to VaShadow for helping on this!
CNC Router Progress
Someone recently asked in a comment what the progress is on the CNC router project. The good news is the Bosch T-nut parts *finally* arrived from L&H. Combined with some M5 screws from the local American Maintenance Supply, I was able to mount the NSK linear slides to the Bosch extrusions. I also picked up some bolts to mount four corner parts to the underside of the frame to elevate it, making room for the center drive down the middle for the long axis.
The next step is to cut and drill out the aluminum plate that will form the sides of the gantry. I also need to get the proper saw blade to cut the aluminum extrusions so I can mount the 45mm x 90mm extrusion across the gantry. Cutting out the hole for the stepper motor seems like it is going to be difficult.
Progress is happening, just a bit slowly. The good news is the next post that is going to contain information about the laser engraver project. :-) It's rapidly progressed.
6-Axis Robot Comes to Life at a Lower Level
The 6-axis American Robot Merlin arm that was kindly donated to the lab by our friend Ken Kurzweil shows new signs of life! Nathan and Adam have been working with it recently. They are working on adding more support to the open-source EMC2 software for 6-axis robots, including teaching pendant support. A DIO card is needed for the host computer to facilitate hooking up the optical encoders and additional stepper drivers.
Here is a video of the robot motors moving based on sine and co-sine functions controlled by the lower HAL layer of EMC2:
One Printer to Rule Them All or Makerbot 3D Printer Now Alive
If you have been by the lab in the last two months, you may have noticed the addition of a new 3D printer: A Makerbot Thing-O-Matic. This device grants us the ability to print objects using ABS plastic (think LEGO brick material) or PLA (a "green" alternative made from renewable material). Check out this young inventor explaining 3D printing.
So, what does this mean for the lab? It means that we now have another piece of equipment in our growing tool set to aid us in our projects. Whether serious or just goofing around (such as scanning people at the lab and printing mini-figurines), the 3D printer is available to members who have taken the training class. The first class graduated two weeks ago and now it is time for the next round for those who are interested.
A little bit about the build process and our results:
The Makerbot Thing-O-Matic is available as a do-it-yourself kit or, for a higher price, prebuilt. We chose the kit, which came in one box with everything seen below (except for the soldering iron, courtesy of Kyle).
Unboxing
We put about 16 hours total into the build, spread out over the course of a week. In the beginning you have to choose one of three types of "build platforms," which is where the material is extruded onto. The kit provides just enough parts to build only one of the three. We elected to use the Automated Build Platform. In theory, this platform allows us to print dozens of items without any intervention. Once an object is printed, the object rolls forward using a conveyor belt where it is pushed out into a collection bucket. After the platform is cleared, the printer continues to print the next object. Our choice in platform may change over time but has been printing quite nicely over the past month as shown in the image below.
Automated Build Platform assembled
Everything went together pretty easily, for the most part, requiring only two small hacks: A single stepper motor driver cable was lengthened as it was too short and an extension connector to the power supply was built to accommodate the Automated Build Platform.
Makerbot build coming together courtesy of help from DJ Mike and Harold (once again sharing some great soldering and electronics knowledge)
Once the installation was completed we had to install and learn some new software that is used to drive the system. You can use most any CAD or modeling package (such as Google Sketch-Up, Blender, AutoCAD, etc.) for designing parts. All that is required is to export the model to .stl (stereolithography file). From here, you use ReplicatorG and open the .stl file after which you have access to a number of settings for "slicing" the model before printing with the Makerbot.
Printing a part
ReplicatorG uses built-in Skeinforge scripts to provide literally hundreds of minor tweaks and changes to fine tune and control your results. After completing calibration (or at least calibrating to a point we considered decent), we started moving to increasingly complicated builds. We have spent the last month running print after print, tweaking settings to provide a good starting point for those interested in printing.
Larger parts
We are pleased to open this tool up to more members of the lab for use in projects. If you already know any of the many CAD or modeling packages out there, you can make your own designs to print. Of course, we are also supporters of the open source design movement found over at Thingiverse. Spend some time browsing and you may find what you need already created or easily adapted!
If you want to get started, the first step is to take a class on working with the machine. More details on the specific settings we use (currently tuned for our cold environment) and how to use, best tips, etc. on our Wiki.
Enjoy and happy printing...
Location
@757Labs
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Links
User Groups
- 757 CCC Comic & Cartoon Creators
- 757 Objective C Group Objective C and Cocoa programming group.
- 757 Python Users Group
- 757.rb Ruby Users Group
- HR Geeks Hampton Roads Geek Community