Projects Abound!

Despite unseasonably nice weather, the members of OMG continue to work on their projects at the Makery or in their garages at breakneck speed. January is traditionally the perfect month for shunning the outdoors and basking in the glow of your computer monitor or, perhaps, the piercing UV glow of an arc welder.

 

Here’s a quick rundown of what’s in the works among the members of OMG:

Alex has made a LED matrix, for some arcane artsy purpose.

The Makery now has new modular workbenches for your hacking pleasure.

The aluminum forge is online, and continues to be improved.  Excerpt from Dave’s explanation,

“…welded together a frame for the tippy-forge last night. I still need to build the stationary part of the frame and put on a handle. What is pictured here is the moving part of the frame that lifts the forge to pour the metal.

After the welding was done we decided it was time to test the new concrete and the lid that Brandon installed recently. We had a couple of minor issues with the burner. There is some leakage of fuel around the input tube that we temporarily sealed with some duct tape. That lasted just long enough to get the aluminum to melt. The propane bottle was nearly empty and started to freeze up on us at the end, the gas pressure looked to be dropping off. We didn’t have time to get the aluminum up to proper pouring temperature, but it was hot enough to at least dump it out of the crucible. The clearance between the inside of the forge (a large soup can) and the crucible (some iron pipe) is a bit narrow, somewhere around 1cm, but the flame swirls around the body very nicely, and when the lid is on the hot exhaust flows over the pouring spout, which is welded to the crucible, which should help keep it hot so that the metal stays warmer when pouring.”

See something here that interests you?  These projects and more are in the works at OMG.  If you have a project you’d like featured on the site, send a photo and description to info@omahamakergroup.org.  Of course, if you’d like to get involved in a project, or need help with something you’re working on, check out the forum.

Until next time…

Makery Glowstick Fashion

Myself and Brandon Essler put together a glowstick holster and a glowstick bracer at yesterday’s meeting, continuing the trend of glowy maker high fashion.

The plan is to eventually wire these pieces up with some sort of LED infusion.

You’ll be able to view these in action at this year’s “New Year Revolution” event.



Maker High Fashion…the EL Coat

Actually, I’ll leave the judgment as to whether this is fashionable to the reader.  Taking a cue from the ready availability of electroluminescent tape/wire to the Maker community, and yes, the recent Tron movie (which re imagined the cult classic costuming in a decidedly more modern twist), it has become too tempting to ignore the possibilities and shaking up the norm.

And so, using white EL tape from Adafruit, two AAA battery packs, a coat I rather like from H&M, and a bit of sewing, viola!  My Jeff Bridges impression is complete, man.

So, project aside, this has got me thinking about the state of change in fashion in the modern age.  Making a coat like this is one thing…how you use it quite another.  I think the Steampunk community must also face this problem.  When you think a certain fringe fashion is cool, do you wear it only among those who also share your (weird) tastes, or do you let that freak flag fly, hoping to inspire?  Let the social experiment begin!

What is this “Variac” Thing?

A Variac (also known as an Autotransformer) is a variable transformer, which allows the user a convenient way to control the power to an AC appliance.  In our context, it’s typically used to adjust the output of a heating device. The variac currently at the Makery is a 20-amp model manufactured by PowerStat.  We’ve configured it to scale voltage only in the down direction, so that the output range is 0-110vac (or whatever line voltage happens to be).  The transformer is outfitted with standard AC outlet fittings, and is mounted to a board for easy transport.  It should be noted that this transformer is NOT isolated, so the output could still be hazardous, regardless of how low the voltage happens to be set.  As with most other equipment, the variac is stored in the TOOLS cabinet.

Easier Vacuforming with Sintra

One of the other projects enhanced by the Variac is the vacuformer.  It consists of two parts: a box with a heating element that melts plastic (background) and a perforated box which sucks the softened plastic down over a heat-resistant form (foreground).  Prior to the Variac, we’d had problems damaging the plastic sheet, because it was heated too rapidly.  Now, we can adjust the heat very precisely and results are much better.

Note: The reason for the incomplete formations in the black plastic (Sintra) is that both the objects used as forms were heavy, metal and cold; The plastic cooled too rapidly, before a good impression could be achieved.

The vacuforming equipment (both the heater box and vacuum bed) are stored in the “TOOLS” cabinet.  There are several shop vacs to be had, typically stored below one of the benches in the “less clean” area.

Acrylic Bender

The Makery’s recent acquisition of a Variac has rekindled interest in a few projects that had been on hold.  One of those projects was the Acrylic Bender that James had been working on. At it’s core, the bender is just a halogen bulb between two aluminum tubes full of circulating water. The idea is to create a line of focused heat to allow plastics to be bent accurately.  We found that it works equally well for acrylic and Sintra (Foamed PVC).  The Bender (along with the Variac) is currently stored in the “TOOLS” cabinet.

Pizza Potluck and Piezoelectric Presentation – December 13th

At next Tuesday’s meeting (December 13th), we’ll be doing a pizza/potluck dinner. The idea is that everyone throw in a few bucks for pizza and bring whatever else they’d like to share. Food is planned for 6:30, but it’s a pretty casual sort of thing.  If you’re interested, RSVP here.

The presentation for the meeting will be Dave, talking about the piezoelectric effect, and demonstrating how make Rochelle Salt (a piezoelectric material).

The piezoelectric effect is the linkage between an electric charge and the mechanical distortion of a material. It occurs in many materials, from crystals and ceramics to bone and DNA. We use the piezoelectric effect in many ways, but we most commonly encounter it in small speakers, audio pick-ups, and grill starters and lighters. Most commercial piezoelectric materials are engineered compounds that are relatively tough and exhibit a strong piezoelectric behavior, but are difficult to create for oneself. However, one of the earliest piezoelectric materials, Rochelle salt, can easily and safely be made at home, allowing us to explore the piezoelectric effect from the ground up.

Even if you’ve never been down to the Makery, or you’ll be a little late, please come join us!

Nerf Gun Mod Challenge Results!

Last night, the Makery hosted a Nerf Gun Mod contest, previously announced here.  We had 5 total entrants, after a few people had things come up at the last minute, and about twice that many spectators.

Appearance

Only Brandon and Eric made an attempt in this category;  Brandon did a functional “pseudo-steampunk” mod (with an extended brass barrel and integrated laser sight), while Eric gave his Nightfinder a complete color revamp using Sharpie markers (Which did come off on his hands).    Eric won almost unanimously, earning him an extra 10% in the distance competition.

Accuracy

The accuracy contest was run next, in a series of 8 rounds, with a point going to the entrant who could hit a whiteboard (At about 15 feet) closest to the center mark. The entrant with the most points won this category.  The contest itself came down to a shootout between Brandon and Dave, (2.5 points each) with Brandon emerging victorious. Eric (2 pts) and Kevin (1 pt).

Distance

This contest measured total distance to rest, thereby including any beneficial or harmful rolling or tumbling that a dart did. A slight accuracy component was involved, in that if a dart went more than 75 feet or so, it had to clear a 5 foot wide doorway.  The low ceiling also proved challenging to some contestants, as it limited the amount that a dart could be arced.

Distance was scored as “best of 8 darts”, with each entrant shooting all 8 in succession.  Brandon’s was the only dart to clear the doorway, making him the winner.  A few darts bounced off the wall, though.  Eric’s 10% bonus (2.2 paces, very scientific) was enough to propel him into 3rd place over Dave, leaving the results Brandon, Kevin, Eric, Dave, Patrick.

Conclusion

Overall, Brandon was the supreme winner, having taken first place in both categories.  Even with a smaller-than-expected field, everyone involved had a great time.  Thanks to all involved for making last night a success! A few photos from the event are below.

Home-made Hobbed Gears

At the Makery lately, Brandon and I [with some help] have been working on a CNC Hot-wire Foam cutter quite a bit like this one.  Ours is going to be a bit larger, capable of slicing up a 2×4 foot piece of foam (actually, the X is more like 5 feet than 4). For our Z axis, we are using a salvaged set of rails including a rack and pinion setup, but our X axis is entirely homebrew.

I’d initially lobbied for a belt setup similar to the X-axis on a Prusa Mendel, but Brandon objected on grounds of the cost for a 10 foot piece of belting.  He proposed instead using a piece of all-thread as a rack, and a curved gear as the pinion.  That was fine, but seemed like the gear would cost more than the belting. In the end, we decided to try making a gear, in the same way that extruder rollers are made for the 3d printers: Hobbing.

Tonight, I got around to trying to make the gear.  We’d settled on 3/8-16 all-thread, as it’d be sufficiently beefy as to not bend with a gear pressing against it, and to not sag under the weight of a mostly unsupported 5 foot span.  I grabbed a piece of (approximately) 1″ round aluminum from the scrap bin, and drilled a 3/16″ hole through.  I bolted the cylinder to a bearing I had lying around, and chucked it into a V-jaw in the mill vise, with one end floating free.  I chucked up a 3/8-16 tap in the spindle, and set the speed as low as it goes (I around 500rpm, I think).

From there, I aligned the tap so that the centermost full thread was parallel to the bolt through the work, so that I’d be cutting only on full threads. I used the Y-axis of the mill table to position the tap along the length of the work, and advanced the work onto the spinning tap by slowly feeding the X axis as the work turned. (The work spun freely in the bearing, powered by the tap cutting into the aluminum, like when a board lifts as a wood screw is driven.)

I initially had a bit of trouble with the work flexing in the chuck (as I was only supported from one end), but I overcame this by grabbing the outboard end of the bolt with my hand and keeping the bolt parallel to the vise jaws manually.

Overall, the process worked really well.  The tap cut nice, deep, uniform teeth into the aluminum. If I were going to do it again, I’d find a better way to hold the work (supported by both ends) in the vise; I’d also pick a better piece of material, as I didn’t bother turning the surface imperfections of out this one before I started.

TacitTheremin: A spatial awareness tool for the blind.

What’s this strange thing?  This is the TacitTheremin, a device which helps blind people understand their surroundings using ultrasonic sound ranging.  Designed to work in tandem with a cane, this device allows users to get a greater sense of what’s around them at ranges that exceed a cane and in any direction in which its pointed.

Inspired by the Tacit, an invention made by Grathio Labs, the TacitTheremin is a modification of that design concocted right here at the Omaha Maker Group.  It mounts to the wrist, receives distance measurements from an ultrasonic sensor, and outputs sound to the user through a speaker (low tones for far distances, high tones for short distances).  It ranges from 16 feet down to 3cm, 5 times per second.

See the original Tacit here.  The TacitTheremin is released under a Creative Commons BY-NC-SA License.

This whole project started as an attempt to replicate a Tacit (because the idea is just so darn cool), and in the end it turned out to look quite different, with different coding as well.  You can read about the epic journey in detail, and make your own for a friend (on an individual project basis).

But enough technical stuff.  See it in action!

Currently, this prototype is being field tested by a local Omahan named Mike, who happens to be blind.  Stay tuned for a followup video.

You can reach me with any comments, questions, or concerns here.  Just be sure and put “TacitTheremin” in the subject.  Alternatively, feel free to comment below!