Jason notes that I forgot to post a photo of the other Mendel parts I’ve been building for the MakeryMendel. Â Below are photos of a stainless steel heater tube (the one that I didn’t ruin by welding a drillbit to the inside) as well as the “order form” that Brandon sent me. His drawings aren’t anything fancy, but we seem to have gotten the job done. Â For scale, the bushing in the photo is 1″ OAL, and the threaded rod heater is 1.5″ OAL. Â The picture with the fire is a prototype plaster bushing that we were testing. Â It’d probably work, but we dried it a bit too fast and it developed a nasty crack.
People I meet via theÂ Omaha Maker Group often ask me what it is that I make. Â I try to avoid the “Everything” answer, popularized by Jason Uher, but it seems to be sort of the truth. Â Due to a renewed Â 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). Â 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. Â 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. Â 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 Â is just 8 banks of 14 (112 total) white LEDs soldered to a piece of perf-board and a connector for power. Â 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 bitÂ embarrassedÂ by my soldering job, so I won’t be posting any photos of that here. Â 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 ElectronicsÂ 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.
While the entire project might have cost a bit more than $5, this remote control plane built by Luke is still pretty inexpensive. Â Check out the videos of it flying at the park last Saturday.
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It seems like everyone had a great time at yesterday’s OMGWTFBBQ, and many people got their first opportunity to visit the Makery. Â Below are some photos snapped at the event; Â If you have more photos that you’d like included, either link them in the comments, or shoot an email to the list.
On an aside, we had more than a bit of food left over from the BBQ, so we’ll be cooking out again at Tuesday’s regular meeting. Â Hope to see you there!
I’ve started to accumulate quite a heap of old smartphones, and would really like them to either get useful or get gone. It was my initial intent to “simply” hook one up as a networked webcam, and have it serve images via HTTP, not unlike the units sold by everyone from Axis to Panasonic. Â Sadly, however, this proved more complicated than I’d imagined.
After quite a bit of procrastination and some help from the guys down at the Makery, I found a package called WebCamera Plus, which only partly fit the bill. Â Half of this packages’ functionality requires a client installed on a PC, where the actual web serving happens. Â Without that “server” PC, the best it can do is FTP photos out on a timed basis.
Adding insult to injury, about the time I was ready to bite the bullet and spend the $20 on this thing, the company sortaÂ disappeared. Â On the upside, the company’s website did resurface a few weeks later, with the software now priced at $9.99. Â The decision had already been made, however, to go in a different direction.
James demonstrates how to wind an extension cord to keep it tangle free and easy to deploy.
One of the features of the Makery (now the defacto name for the Omaha Maker Group’s space) is a standing webcam that publishes live photos of the space to the Internet. Â We have a few USB webcams hooked up to a PC running YawCam, which is a free (as in beer) webcam package written in Java. We run one copy of the software per camera (Copied into separate directories, as the config is file-based) and each serves its image on a separate port.
Initially, people were having problems accessing HTTP on non-standard ports, but Â we weren’t inclined to “use up” port 80 on our only IP address with just one webcam; With some help from the mailing list, I hacked together a Perl script that runs on our website hosting provider and proxies requests to the camera server’s separate nonstandard ports. It then re-serves the images on port 80 and also uses GD to return text images in the event of an error (like a timeout fetching the webcam image). This setup has the added benefit of masking the firewall’s IP address from the website, and would even support cameras on multiple IP addresses that look like a single image.
At Dave’s request, I also included “indicator pixels”, to coordinate with his “are the lights on” python script.
Overall (for my part, at least), it’s sort of a hackjob, but it seems to work pretty well.
Today was a pretty full, if short, day at the Makery; It started around noon, when the power was out as we arrived; It turned out to be a circuit breaker that must’ve tripped overnight somehow.
Once power was restored, work continued on both the robotic arm controls and the partition wall that now divides the overhead door area from the “kitchen table” area. Â The partition itself is made up of 5 4’x8′ Â panels, which are pinned and bolted together, and then painted.
Brandon also made quite a bit of progress on the “dis-armed” z-axis of the robotic arm he’s beenÂ dissecting. Using an Arduino and an old Traxxas speed control, he had the linear actuator going pretty reliably, though the speed control might be missing some magic smoke now… Â A short video of the arm is here.
Following last night’s meeting, a number of Panasonic Industrial robotic arms were dropped off at the Makery. These arms were used in some sort of assembly operation, and seem to have been manufactured (at least the motors) in the early 80s. A number of people hung around pretty late messing around with them, and had them moving under their own power on pretty short order.
There are some videos from last night, which are now available here.
Any ideas for what they could become? Brandon recommends that they NOT be used as an arm-wrestling simulator 🙂
The next regular meeting will be at the space on Tuesday, April 5th at 7pm. We’ve got two presentations:
Brandon will be showing his progress on the remote controlled Tricopter he’s been working on (as seen on this site); If you’re unfamiliar with exactly what a Tricopter is, it’s like a quadcopter with just 3 rotors.
Nick will be pre-presenting his paper on SCADA, an acronym used to describe the systems used to control the supply of electricity, water, gas, and so much more. Because of their high profile status, SCADA systems have been garnering a lot more attention from unsavory elements. This talk represents an introduction to SCADA systems and attempts to look at the challenges in securing them.
The space will be open starting around 5:30 on Tuesday through whenever people leave after the meeting. (Though the meeting typically runs from 7 to 8 or so). See you all then!