todo, DIY vending machine (countertop and oshw)

Like this, but with arduinos. and caffeine. and breadboards. and 1/64” drill bits. and nyancat-etched poptarts. Oh, and open source. And constructable for less than $600.

(I get to the whole build-my-own vending machine thing further down the page. Got a bit ADD).

Well, in other news, my 2.008 group did not fall over themselves to build a PoV yoyo. This is okay. I will just make one or two PoV (persistence of vision) yoyo’s manually then. (you, dear reader, have just been saved from a pages-long rant as I sulked over the last few days :P)

In other news, in MAS.863, it’s waterjet and shopbot week! I’m super-excited.

<3 3-axis mill. Shopbot r awesome~

(look, someone made a giant scrabble set using the media lab shopbot:

http://mako.cc/copyrighteous/20110725-00

)
Mini projects this week:

[1] Shelving. make this (playatech’s plans — rec’d by fellow classmate novysan, who had fun with these at burning man. also rec’d “nomadic architecture” which sadly did not mean nomadic furniture like Walking Hexapod Racing Chair but rather furniture suited for nomadic humans)

http://www.playatech.com/index.php?deptName=03Bare%20Necessities&prodDesc=09Gear%20Gizmo

(aka shelving made from one sheet of $8 7/16” OSB plywood,

http://www.homedepot.com/h_d1/N-5yc1v/R-100091344/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053)

Artsy furniture (metal): http://dornob.com/open-source-free-flat-pack-plans-for-laser-cut-furniture/
Styrofoam furniture: http://dornob.com/laser-cut-styrofoam-seats-solid-3d-polystyrene-chair-design/

[2]  I have lots of marble leftover from our clock class, which some people took proper advantage of while I merely used lasercutter and acrylic:

classmate’s AWESOME marble koi fish clock

mmm, instant noodles. aww. I miss my old room.

Oh right, where was I?

Arduino vending machines. That’s right. Make a DIY “open-source hardware” vending machine. Not interested in the electronics of accepting money and such (although that’s what everybody leaps to help with that, despite me explicitly stating I’m more interested in the vending mechanism).

Research:
http://en.wikipedia.org/wiki/Vending_machine#Mechanism
www.discapa.com/eng/download/manualt/MTMacSpiralE — coin mechanism and spiral set? not sure what it vended
http://www.vending.com/vending_machines/combination_vending_machines/combo/manual/
So they’re called “augers.”

from: http://www.vending.com/vending_machines/combination_vending_machines/combo/manual/

Found! mcmaster-carr “Dry goods screw conveyors”

http://www.mcmaster.com/#auger-conveyors/=ecttus

 ?!?!?! $677 is the cheapest one?! holy shiznatz that is out of the question.

Smexy pdf images: http://www.screwconveyors.com/profile2006x.pdf
mmm online worksheet AND considerations pdf:  http://www.kwsmfg.com/products/Screw-Conveyors.htm, http://www.kwsmfg.com/pdf/KWS-0709PBE.pdf . So I want “shaftless screw conveyor”
Ewww, this just ‘cos it has a pic of a screw conveyor used in a slaughterhouse: http://drycake.com/equipment/screening/downloads/Screening_Catalogue.pdf
Making Things Talk mentions it briefly… I wonder where I get a “big screw” (via libproxy.mit.edu): http://proquest.safaribooksonline.com/book/hobbies/9780596510510/chapter-9dot-identification/301?reader=pf&readerfullscreen=&readerleftmenu=1

Interesting tidbits about vending machine locks: http://books.google.com/books?id=6tRcZtGADBcC&lpg=PA142&ots=KBqWOPS2Jk&dq=vending%20machine%20screw%20mechanism&pg=PA143#v=onepage&q=vending%20machine%20screw%20mechanism&f=false

NyanCAD: Correct motivation for learning CAD

I’m embarrassed to say how many hours I’ve wasted CADing nyancat paperweight for 2.008 now.
Off to go spend even more time producing CNC mill G-code using Mastercam for a machining appointment at 8am o__o

10/1/11 Edit:
Aha, so I realized (thanks to Steve, shop instructor extraordinaire) that there are many things wrong with my CAD. Sadly, I chose 5 mils spacing for the grid I used to trace nyancat. Turns out our smallest drill bit is 1/16” ( over 6 mils). Eheh. Also, I was planning on going 0.3” deep, which would take forever to mill out using 1/16”, as it can only go ~0.02” down per z-axis pass.

yea, milling fail.
that, dear friends, is the look of a lot of milling time.

I was halfway through the infuriating MASTERCAM too. Lesson learned: avoid branching as much as possible. See that right-most sprinkle that touches the cat’s head? Caused me no end of trouble!

Next step? Infinite Mastercam’ing. Instead of being a nice cavity with extruded nyancat, it’ll probably end up being closer to pedestal with a nyancat on top done in thin layers. I’ll also use a larger diameter tool to pocket out each shape and then contour with the 1/16”. So, first up, redo solidworks using 0.7” grid spacing (resize reference picture accordingly — btw, found under insert > sketch tools > sketch picture).

I’ll stick the files up on github sometime soon.

=====
Todo this weekend:
Saturday: Get ISP and PoV working, 6.131 lab writeup, MITERS misc. (project grants / safety / update website), PoV with partner 10am, Theater scene practice 2pm. Apply to summer jobs.
Sunday: 6.131 lab (1pm to midnight), 2.008 group meeting 7pm, watch a play (3 pm), go visit Sprout? (2pm)
Monday morning: lasercut cookies, document cookies and ISP.
Oh yea, speaking of ISP programmers, this week’s assignment was to mill ISPs using these desktop Roland Modela 3d mills:
So someone made an even tinier one that doesn’t need a USB connector (fits right into the slot): http://bardagjy.com/?p=628
Then someone riffed off of that and made one that has a break-off part for bootloading the chip:
http://fab.cba.mit.edu/classes/MAS.863/people/valentin.heun/2.htm

Machine Shop Safety: Yale and the Missing White Woman Syndrome

MITERS is a student shop on MIT’s campus. Funding-wise, we run independently of any MIT department, which is great since our projects don’t exactly fall into research all of the time. We also don’t have to pay rent or utilities due to being located on MIT property. However, this also means that for better or for worse we are subject to the scrutiny of MIT’s space administrators and Environmental Health and Safety staff.

MITERS runs a delicate balancing act that, for me, strikes home two contrasting trends: increasing paranoia (and safety) over the years (perhaps best dramatized by 9/11 and Homeland Security), and increased interest in the amorphous idea of the “maker movement.” I am torn. Sometimes I am skeptical; Traffic mentions that the number of deaths from parachutes leveled off and has remained constant despite increased safety measures; what happened was that better safety measures made people comfortable with taking greater risks. Sometimes I am cautious; Traffic also mentions that we are all overconfident drivers, believing the past predicts the future as we confidently take to the roads (one study showed that ambulance drivers, because of the urgency of their mission and contrary to what many would think, actually drove “better” — turning sooner and driving more smoothly — than the average driver).

Recently, the Yale death (I apologize to those still in mourning for this crass mention) has lead to scrutiny of the sort that makes all of us at MITERS a bit uncomfortable. Our machine tools are old and no one would mind a newer mill or lathe or better safeguards. However, we all seem to feel instinctively that too much scrutiny on any level is toxic to the creative haven of MITERS (and dear lord, apparently a ton of grad students will be moving into our building which will be fit for the Prime Minister of Singapore to look upon within a year or two — that’ll be interesting, but no point in worrying just yet). In reaction, my fellow MITERS officer Julian Merrick remarked that this situation seems reminiscent of Missing White Woman Syndrome, where there is a disproportionate reaction to unfortunate cases involving people of one class (white and female) as opposed to another (male, other ethnicity). Indeed, a google search turns up a thread on Practical Machinist remarking the same.

One surprising constant throughout the ongoing whole process, however, has been people’s appreciation of the output of MITERS. Uniformly, people have been supportive of MITERS, even if we may have different ideas of the kind of support needed. Ultimately, I am hopeful that we will emerge through this with better safety and our core culture intact.