Champaign-Urbana Community Fab Lab
Champaign-Urbana Community Fab Lab

"Friends" Committee Notes, 12/16/2010

The CUCFL “Friends” held the first general meeting on Dec. 16, 2010. The next meeting will be 20 Jan 2011 (tentative). Please find attached notes from the Dec. meeting. — REMcG, acting chair Full post and discussion here: http://www.fabhub.net/showthread.php?56-quot-Friends-quot-Committee-Note… Friends meeting_12_16_2010
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“Friends” Committee Notes, 12/16/2010

The CUCFL “Friends” held the first general meeting on Dec. 16, 2010. The next meeting will be 20 Jan 2011 (tentative). Please find attached notes from the Dec. meeting. — REMcG, acting chair Full post and discussion here: http://www.fabhub.net/showthread.php?56-quot-Friends-quot-Committee-Note… Friends meeting_12_16_2010
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New Facebook Page for the Champaign-Urbana Fab Lab

We’ve created a new Facebook Page for the Champaign-Urbana Community Fab Lab: http://www.facebook.com/pages/Champaign-Urbana-Community-Fab-Lab/177273545636056 In addition to actually using the page, links to posts on the Fab Lab website are automatically posted to this page’s wall. We’ve also added a “Share” button to our website that will allow website users to easily link to content using dozens of social networking services. Lastly, since I post on cucfablab.org far more often than I post on Facebook, I’ve set up my Facebook account to automatically share items that I post in “Luke Scharf’s Blog“.  If anyone wants to see how to set this up, let me know and I’ll either show you how to do it or post a writeup.
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Luke's Fab Lab Cheesecake Platter v1.0

Goal: Create a cheesecake platter and trophy for a series of cheesecake competitions related to the Fab Lab. Bill of Materials:
  • 1 24″x12″x1/4″ sheet of clear acrylic
  • The attached design-file (cheesecake_platter.svg or cheesecake_platter.pdf)
Design:
See attached .svg (easily editable) or .pdf (straight to the Epilog print-driver) file.
Photos:
Luke's Cheesecake Platter - Perspective ViewLuke’s Cheesecake Platter – Perspective View Luke's Cheesecake Platter - ComponentsLuke’s Cheesecake Platter – Components
 
Epilog Settings: Standard settings for 1/4″ Acrylic:
  • Raster:
    • Speed: 100
    • Power: 35
  • Vector:
    • Speed: 8
    • Power: 100
    • Frequency: 5000
Future Improvements:
  1. Flip platter: Flip the platter so that the artwork is on the bottom, rather than on the serving surface.
  2. Reduce the play between the components:  There’s a bit of play between the tabs and the plate, probably because of the kerf of the laser — so it’s easy to pick up the top tray and leave the base on the table.  Gravity holds it together nicely, though, and this version is likely to work with a wide variety of materials, such as acrylic from different manufacturers, and even 1/4″ plywood.
  3. Improve the artwork:  The pixilated Fab Lab Logo really does evoke the “digital” in “digital fabrication”, but some of the stray pixels can be distracting.  There are also some unrealized possibilities for decorating the legs.
  4. Improve the speed of fabrication: Using line-art for the platter graphics could greatly increase the speed with which this project can be made.
Intellectual Property:
Luke's Cheesecake Platter - Perspective View
cheesecake_platter
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Luke’s Fab Lab Cheesecake Platter v1.0

Goal: Create a cheesecake platter and trophy for a series of cheesecake competitions related to the Fab Lab. Bill of Materials:
  • 1 24″x12″x1/4″ sheet of clear acrylic
  • The attached design-file (cheesecake_platter.svg or cheesecake_platter.pdf)
Design:
See attached .svg (easily editable) or .pdf (straight to the Epilog print-driver) file.
Photos:
Luke's Cheesecake Platter - Perspective ViewLuke’s Cheesecake Platter – Perspective View Luke's Cheesecake Platter - ComponentsLuke’s Cheesecake Platter – Components
 
Epilog Settings: Standard settings for 1/4″ Acrylic:
  • Raster:
    • Speed: 100
    • Power: 35
  • Vector:
    • Speed: 8
    • Power: 100
    • Frequency: 5000
Future Improvements:
  1. Flip platter: Flip the platter so that the artwork is on the bottom, rather than on the serving surface.
  2. Reduce the play between the components:  There’s a bit of play between the tabs and the plate, probably because of the kerf of the laser — so it’s easy to pick up the top tray and leave the base on the table.  Gravity holds it together nicely, though, and this version is likely to work with a wide variety of materials, such as acrylic from different manufacturers, and even 1/4″ plywood.
  3. Improve the artwork:  The pixilated Fab Lab Logo really does evoke the “digital” in “digital fabrication”, but some of the stray pixels can be distracting.  There are also some unrealized possibilities for decorating the legs.
  4. Improve the speed of fabrication: Using line-art for the platter graphics could greatly increase the speed with which this project can be made.
Intellectual Property:
Luke's Cheesecake Platter - Perspective View
cheesecake_platter
  Continue Reading

Christmas Tree Christmas Tree Ornament

The other day I  found an object on Thingiverse that I wanted to make because it’s close to Christmas. THE Christmas Tree Christmas Tree Ornament! The design can be found here: http://www.thingiverse.com/thing:170 Making it was easy enough. I knew that the pattern from Thingiverse would give all the parts for two trees so all I had to do was stack up the circles in order of size and then split them into two groups. groups of circles Then I put them together making every other layer one of the really small spacers. making trees Now, one tree is bigger than the other, but by moving a few of the last circles off the shorter tree to the bigger tree they balance out quite nicely. The last touches were the strings on the top and two small bits of string on the bottom to hold the stacks together. Now I have two little tree ornaments to hang…. if only I had a big tree to hang them on. two trees
two trees
making trees
20101213191530.jpg
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Intelligent Toaster Project

“May I Just ask one question… would anyone like any toast?” In so far as  
  • most electrical components today are offered as surface mount technology (SMT)
  • fine pitch surface mount components require special care in soldering, to avoid solder bridges (shorts) between leads
  • high pin count SMT devices, and especially four-sided components (PLCCs, quad flat packs, etc.) can suffer from assembly skew if the leads are soldered “sequentially”
  it follows that a bulk reflow mechanism is a desirable resource. Specifically, a device that can  
  1. warm an entire (small) PCB to a target preheat temperature (perhaps 150 F)
  2. rapid heat (“flash”) the top surface of the board to solder reflow temperature (e.g. 400 F) for a controlled amount of time
  which will cause all of the solder joints to melt concurrently. The SMT component(s) will then be free to self-center on the copper lands of the PCB, courtesy of surface tension. Further, as long as the amount of solder (paste) on the board is minimal, the individual puddles of solder should collect on the individual copper lands, and not bridge across them. Also courtesy of surface tension. In commercial facilities, this can be done with hot air, infrared, vapor phase, and convection ovens. Of these, the easiest to fabricate (personally) is the convection oven.   Mission statement Adapt a toaster oven for computer control. Provide temperature sensing and heater element (on/off) control; develop a “temperature profile” editor (software) to allow the user to “draw” a target temperature profile for the oven to follow; develop real-time software to control the oven according to the profile.   First guess at required resources  
  • toaster over
  • PC
  • temperature sensor
  • solid state relay (120V, 1300W switching capability)
  • small PCB to serve as cable connection point (with DB9 serial port connector)
  • (maybe) microcontroller, to sit between the PC and oven, to provide USB interface as well as watch-dog shutdown (failsafe mechanisms(
  Note: the following content belongs on separate pages. However, at this time, I am unable to create visible, persistant content. But as long as I remember the URL to this page, I can keep coming back to it…   9 Dec 2010 Purchased 2nd-hand toaster oven from Twice is Nice, the First Presbyterian Church resale shop on Elm Street, in Urbana.
  • Hamilton Beach model 336. 1300W. $2
Spent 30 minutes with steel wool (and sand paper) removing burnt-on food residue. This unit will characteristically be operated at high temperatures; best to remove organics now…   Test run. 2″x1″ pcb (scrap) with a 0.5″ piece of lead-free solder (wire) on top.
  1. “Baked” until 250F (assuming that the front panel thermostat still works). 5 minutes.
  2. Cranked thermostat to “Broil”. Solder melted with 30 seconds!
  3. Cool down (to the point that I felt was safe for a stranger to touch) took 20 minutes Frown
It may be desirable to position the PCB closer to the top heater element. However, it may also be wise to provide tin-foil “hats” for silicon, to avoid top-browning…   Need for next time:
  • oven mits
  • tongs (needle nose pliers are not adequate)
  • oven thermometer (to check front panel thermostat)
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Discussion on Fab Academy Hosting & Participation for Spring 2011

NOTICE A DISCUSSION ON FAB ACADEMY HOSTING & PARTICIPATION FOR SPRING 2011 AT CHAMPAIGN-URBANA COMMUNITY FAB LAB WILL BE HELD ON THURSDAY DECEMBER 2 @ 5:30 PM THE PROGRAM: http://academy.cba.mit.edu/about/index.html A Fab Academy prep video (Fab Lab videoconference at mcu.cba.mit.edu) is set for 9:00 am Boston time over the polycom next week on Tue Dec 7 – attend if you can! RSVP
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