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Category Archives: Making
Learn about Lockpicking from a Toool.. member
Would you like to learn about lock picking? Come to our meeting Tuesday July 10th @ 7pm.
The meeting will feature a talk from a member of Toool.us (The Open Organization of Lockpickers), Steve Beck.
Steve will cover three topics, two of which are a little more hands on-ish, the first will be a basic lockpicking talk, the second will be a re-keying talk with a demo and the third will be about making your own picks with a demo.
Stick around after the talk for socializing and Makery Shenanigans.
Balsa Bridge Bash Results (with movie of stuff breaking)
Results are in! 
After a run up of making throughout the week, the bridge competition began at the Makery last Sunday to test the designs of our participants. In all, there were 9 entries (some last minute).
In short, the rules:
Bridge:May contain only balsa wood and Titebond 2 wood glue.Must fit within a 50 x 20 x 10 cm rectangular volume.May not contain more than 6oz of glue by wet volume.Must have a smoothish road deck no less than 6cm in width.- suitable for a HotWheels-style car to easily roll overDeck ends must contact the upper surface of the test rig support planks.Deck must have no more than a 10% grade (where grade = 100 * (rise/run))Deck must accommodate the load plate.Some part of the load plate must fall across the midpoint of the span.There are no limits on construction tools or technique.Scoring:The load plate is 10 x 5 x 1 cm, and has a loading hook extending from the center of the bottom surface which requires 1 cm annular clearance through and below the bridge deck.Bridges will be loaded progressively (w/ minimum shock load), starting at 5kg and progressing in 1Kg increments to 10Kg.Upon reaching the maximum load, the bridge must hold for 1 minute.- Disputes as to whether a bridge ‘held’ will be resolved by voteBridges that fail will be ranked by the weight carried without failure and bridge mass.Bridges that do not fail will be ranked by the mass of the bridge.Testing:The open span between the support planks is 30cm.The open span is between rectangular, fixed, smooth, level, coplanar planks with a thickness of ~2cm.The bridge may touch the top or inner surfaces of the supporting planks, but may not touch any other surface, nor be affixed to any surface.The load plate will support a wire or rod from which the test load will be suspended.
And so, our bridges took to the field. Most, thankfully, were able to take the designated test weight. Ironically, the ones that didn’t pass the test seemed to fail because of over-engineering. The resulting bridges flirted a bit too close to weight limits and efficiency and ultimately couldn’t stand up to the test weight. The results:
As you can see, Dave K emerged victorious, with a design that was the lightest to survive the task of lifting 8kg, and which went on to lift 1452.61% of its own weight. Impressive!
By now you may have worked out that there is a category in the results called “Fail Weight.” Well, we at OMG like to test to the limits of design. Also, we’re all about 8 years old at heart and like to break things, filming the results in slow motion video if at all possible. So, without further ado…every last bridge getting destroyed/max tested to sexy music:
Join us for our next competition, to be held this Sunday! See the forum for details.
New Ring-Light
People I meet via the Omaha Maker Group often ask me what it is that I make. I try to avoid the “Everything” answer, popularized by Jason Uher, but it seems to be sort of the truth. Due to a renewed interest [by people who aren't me] in things that I’m making, I’m trying to do a better job of actually driving these projects to completion, and maybe even doing a slightly better job than I otherwise might. I’m also trying to do more projects that are more “grand” in scale (for example, building a power supply, instead of a really neat custom connector; Not that either of those are really grand, in the big picture). Below is one of these projects.
After lots of fiddling with desklamps and bounce cards every time I want to take a decent macro photo, I’d finally had it. I started looking into buying a ring-flash accessory for my digital camera, but found them to be alternatingly pretty expensive or in the realm of “I could build that”. So I did. Read on for the details and a few more photos.
I determined early on that I didn’t want or need a flash-tube-based solution (like the one built by Patrick), which is a reflective ring illuminated by a standard photo flash. I didn’t want to spend the money for a fancy “automatic” external flash, and didn’t want the headaches and setup associated with a cheap manual flash.
I did some initial research on running an LED illuminator on the camera’s hot-shoe trigger, but decided that it really wasn’t needed, as LEDs can just be turned on and off and don’t need to be “fired” like a xenon flash. My illuminator is powered by a simple pack of 4 AA batteries (ideally NIZN for the extra .3V).
The illuminator itself is just 8 banks of 14 (112 total) white LEDs soldered to a piece of perf-board and a connector for power. To make it run on 6 volts nicely (and to give me more input voltage range), I wired both halves of the LED array in parallel and then the two banks in series. I could have just put the banks themselves in parallel (and run the array on 3ish volts), but that would put my total current draw at over 800ma, which I opted to avoid.
I found a pretty neat online schematic designer, so I whipped up a schematic, in case you can’t picture what I’m saying:
From a physical standpoint, the LEDs are just soldered to the perfboard and surface-wired on the back side. I’m a bit embarrassed by my soldering job, so I won’t be posting any photos of that here. I cut the hole in the center of the board with a few forstner bits, and finished it out with a sanding drum in a Dremel. I plan on gluing a 58mm filter ring [generously donated by Don] to the back side of the board so that it can attach to my S5′s filter adapter. I’ll probably just Velcro the battery pack to the side of the camera, as this rig is mostly for use on a tripod.
One problem I have come across is the convergence pattern on the LEDs. At distances less than about 8″, there’s a bit of a dim spot at the center of the frame. This should be correctable with some sort of diffuser and a bit of tweaking of the LEDs angle.
As for the LEDs, they were ordered from Tayda Electronics for $8 shipped ($0.04 each, plus $2 shipping). At 3.1ish volts per bank, I’m under-volting them just a bit, but they seem plenty bright.
Below is a few more pictures of the light, plus a photo of another project, demonstrating the dim spot. More photos of the device will follow, as soon as I get it into a more final form.
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