MIT Electronics Research Society | (617) 253-2060
Nancy gives a lecture on how to github:
It’s nail painting night at MITERS!
nancy edits on 2 dec 2011:
for reference, I talked (actually mostly I evangelized open source hardware and mentioned rise of EE but not really meche-oriented version control, then most people already knew how to use git & github) about:
You have to start building somewhere, so MITERS frosh Walter came by this past week to add a sound system to his bike!
It doesn’t have to be complicated, spectacular, or outlandish to be built at MITERS!
This is a cross-post from muffin’s blog!
Over the weekend, Dan disassembled a laser printer that he found in the trash. He was able to tear it down to the point where he could fit a board in the (quite linear) print path and gave it a go. To his dismay, the board jammed and nicked the heating drum. I came over and we decided that by removing a metal guide and chamfering the edge of the circuit board, we’d have better luck – and we did! The print quality turned out pretty good, but the toner wasn’t fusing to the board. We figured that it was either a heat/pressure issue or a charge issue and called it a night.
The next day, Dan and I went to [miters](http://miters.mit.edu) to improve the process. We tried a whole slew of ideas include charge compensation, increasing roller pressure, and pre-heating the boards to get the toner to fuse. The last one did the trick. Although print quality isn’t 100% there yet, we’re certain that we can hammer out those last pixels and get this process rolling. We etched my first lab in 6.331 – a 4MHz 50-ohm line driver with 2 watts of output power.
More to come next weekend!
Because documentation is good, I hear…so here’s documentation of an old-ish (circa this June) project.
Inverter is a fullbridge of CM400 IGBT modules, matching transformer is something like 20:1. The whole thing resonates at ~65KHz. The driver is a simple fixed-frequency oscillator.
Sorry ’bout the lack of video…seems like I was too busy setting things on fire and forgot to video it =( Remember kiddies, setting a CDE940 film cap on fire=Terrible Idea!
I made nyancake! It was more difficult than I thought it would be. “In other news this week, hall thanksgiving feast. Nyancake makes its appearance. Trickier than I thought. Sprinkles did not turn out at all (too fine featured), cake should not be too moist (add flour). Bake at ~325F for ~1.5hrs, then (when brown on “top”) pull out and invert. Let cool for ten or twenty minutes, then gently shake out. Make sure to use cooking spray as mold release!” This used $17 worth of food-grade silicone, and I just barely made it by adding a top to the mold with foam to displace the silicone where it wasn’t needed in the mold.
As a whole, jello is much more recommended, but has more limited post-processing (aka adding food coloring / frosting) options.
I finally managed to not eat poptarts long enough to drag them from Shaw’s, the grocery store, to the media lab shop (this has taken me 2 months, hah). Now I have replicated the work of http://www.lvl1.org/2011/07/15/new-laser-cutter/ and created laser-etched nyancat poptarts!
MATERIAL: LENS: THICKNESS: PPI: POWER (%): SPEED (%): EFFECT (cut/etch)
Poptart 2 n/a 500 40% 80% Light raster (will cut through sugar but not burn poptart)
Poptart 2 n/a 500 40% 50% Medium raster (will cut through sugar and lightly singe poptart)
Poptart 2 n/a 500 76% 50% Strong raster (will cut through sugar and darkly singe poptart)
on the universal laser x2-600 (co2, 100w).
An update from rapid-prototyping land.
I have access to a shopbot and CNC mill now, which means I can now create infinity nyancats!
(there was this really awkward moment in the media lab shop where these sponsor-y people walked in and looked around and took pictures. While I had nyancat on my screen and I was using this 50k shopbot 3d axis mill to … cut internet memes out of foam).
Foam to smooth-on liquid silicone (in this case, mold star slow, which has a long pot time to work with — 50 mins — but takes 4 hours to cure. the quick-curing oomoo 25 was out) to drystone final (similar to plaster — a white powder, mix with water and let stand for a few hours). No release agents needed at any step, although I had to pry the silicone out of the foam, destroying the mold a bit.
Final drystone version had bad surface finish due to the bad surface finishing on the foam (I was trying to cut down on my shopbot milling time) — professor suggested coating foam version in gesso next time to create a better finish. I also lost a sprinkle on the foam somewhere, and was not careful enough pouring the drystone into the silicone mold as you can tell from the uneven depth of the sprinkles.
Aluminum paperweight (engraved on a CNC mill) > oomax silicone (cured in ~1hr) > drystone (cured in ~1hr) and a black smooth-on plastic (cured in 15 mins). There are tiny bubbles in the silicone version along the raised lines, probably because I needed to be more careful making sure the oomax poured all the way into the tiny etched grooves.
google images (nyancat) > Solidworks (3d model / dxf) > MasterCAM for the aluminum paperweight, Partworks for the shopbot foam mold.
and more pictures here:
Update– now we’re awarding $750 in total! Thanks to techfair — techfair.mit.edu
MITERS wants to give you money (“makerships”) to work on your own projects.
Apply here by Tuesday the 11th (it’s a short and sweet form):
The details follow…
We want to give you money for your projects. We’re allocating $500 a
semester toward grants for student (undergraduates only for now)
projects. (So requesting up to $100 or $200 is within reason, although
smaller requests are more likely to be granted).
MIT Electronics Research Society (http://miters.mit.edu)
Originally founded as a club to give MIT students free and open access
to computers, MITERS now features a mill, lathe, band saws, welders*,
and other hands-on tools, in addition to a host of oscilloscopes,
high-end soldering irons, and other EE prototyping tools. It’s a
member-run creative haven and build-anything-you-want,
*currently out of operation, we’re working on fixing
* Oct 11 — Last day of Columbus weekend — application deadline
* Oct 14 — Winners notified
* Dec 16 — (tentative) MEETERS (MITERS End of Every Term Research Showcase)
* Undergraduate (any school, as long as you come hang out at MITERS)
* Work on the project at MITERS as much as possible
* Present at MEETERS (probably Dec 16th)
* Maintain good documentation of their work as you progress. On your
website or on the MITERS website is fine. (this is good for your
future/present portfolio too)
Judging: Names will be stripped from proposals, then I’ll email
everyone on the miters-keyholders list (about 20 people) for voting
and discussion (coolness / technicality will come into play here).
Final decisions will be made at general meeting Friday Oct. 14th
(affirmative action in encouraging new makers / underclassmen will
come into play here*), and winners notified by that Saturday (Oct
*Yes, I am explicitly stating that you should not be intimidated by x
crazy project you see on the MITERS site. All you really need is
enthusiasm for making things — the rest will come naturally as you
ask people at MIT / MITERS for help with your crazy idea.
Why: We are funding this to convince more people to join MITERS and/or
Money distribution: You would come to Friday build parties (every
Friday @ 7pm @ MITERS) and pull up website(s) for us to order your
parts from. This way we cut through the reimbursement craziness and
don’t even step near cash-grant sinkholes. If you absolutely want your
part but can’t make it, I’ll create a spreadsheet doc that our
treasurer, tylerc, can check.
Build parties: Basically, a bunch of people who like making things
comes to hang out at MITERS. No dancing involved [yet].
Majors: We don’t care what major you are. And we’re definitely not
pure 6-1. We’re self-funded, so not directly tied to any department.
If you want a copy of what you submitted here, just email me and/or
save it elsewhere before you submit.
Short little video of a modified IKEA leaf canopy now-turned planetarium. Who said etextiles were only for clothes!