Acrylic Chill Box Build

This past week saw a few major steps in the chill box. This post describes building the acrylic container holds the parts and the plantings..

Cole came over to my (Jerry) home on Friday to work on the container.  I had a couple long (8×2′) sheets of 1/4″ acrylic.  We picked one and then cut it in half with a jig saw. The cut was pretty rough but it allowed us to put the resulting panels into the open door of the laser cutter.  We cut them down to three 24″ x 9″ and some 9″ x 9″ panels. The long ones are for bottom and sides, small are for ends and dividers.

[slickr-flickr tag=”ChillBoxAcrylic” descriptions=”on” flickr_link=”on” sort=”title” ]

To make assembly easier, we etched 1/4″ grooves around the edges of bottom and across side panels for the other panels to sit in.  This worked fairly well, except for some alignment errors that resulted in a ridge along the edge of bottom panel. Also the Corel Draw document used distinct overlapping lines. When etched, each line was rasterized and drawn in total – where they overlap was etched twice each pass, making a pocket.  Learning Experience!  Also, these wide grooves were rendered as rasters and when doing the short cross grooves, there was a LONG time spent moving between them…. Etch 1/4″, move 14″, etch 1/4, move 12, etch 1/4″… on each raster line.  To speed things up, I split the three cross pieces up into three separate jobs. The result was faster total time… although this may have contributed to creating the pockets.

Next we figured we need to etch some things into the side panels and cut some ventilation slats in the chiller area.  I spent some (too much) time updating the Maui Maker logo and placed it along with “Chill Box” text in the planter area.  I figured we would etch these into the inside for better effect so I mirrored the image horizontally so the text would be readable.  Then I mirrored vertically so I could etch in one pass. It wasnt until everything was complete that I realized the 2nd mirror had reversed the text again. When viewed from outside that one side’s text is backwards.. Learning Experience!

For the ventilation slats, we could have gone with a big hole or simple cutouts, but thats too easy and simple.  I opted to get artistic.  On one side I created a set of sine waves of different frequencies.  This took a fair bit of time as I learned how to make such lines in Corel Draw, offset them and then join the lines to make a cut out area.  Learning Experience!  To increase the open area, I added some circles.  Unfortunately I did not check the results closely.  When the waves were cut, a couple points were very close together, and effectively broke through where they shouldnt have.  Learning Experience!!

A Handful of Elementary Particles

For the other side, I thought, hmmm, Garrett’s E8 diagrams are pretty cool and would result in a lot of holes for wind to blow through (no reflection on his Theory of Everything). I popped over to the really cool E8 Elementary Particle Explorer site and came up with something half decent. I emailed the image to Garrett with background, just to get a sanity check.  He quickly returned my email with an even better diagram, specifically with axis, labels, etc removed.  I dropped this into the Corel Draw and ZAP! we had a mix of Agriculture and Theoretical Physics.. Fitting for our rather diverse maker group.

Laser settings for etching and cutting the 1/4″ acrylic:

  • Raster: 400dpi, Speed 20%, Power 100%; Required 2 passes to get good depth
  • Vector: Speed 5%, Power 100%, 5000Hz; Required 3 passes to completely cut

After all the etching and cutting was done, I setup my Festool table for assembling the box.  Actually, I had it setup after we cut the pieces and was checking fit, measurements, etc at stages all along.  The table is rather nice with large holes into which special clamps are inserted. These hold the work pieces securely in place.  I put a couple scrap pieces of wood between the clamps and acrylic so as to get a good straight edge and distribute the compression forces.  When all the pieces were cut, etched and test fitted, I squeezed a bead of Weld-on #16 acrylic cement into the grooves on bottom and side panels and assembled. (Note for next time – Have someone else around to help hold pieces in place.) The I put clamps on the top edges near or on the end/center panels, padding the metal clamps with some scrap cardboard. I left the whole thing dry in the clamps for 24hours. The end result was pretty nice looking – although there were a few places where the glue squeezed out and got some of the paper stuck. These can be touched up somewhat afterwards, but the larger one will leave a permanent blemish.

Completed Acrylic Chill Box in clamps

Lessons learned:

  • Acrylic stinks when etched/cut. We need a ventilator that scrubs the exhaust. Commercial ones are expensive but perhaps necessary. Perhaps we can make one using simple water tower-in-a-bucket?
  • Acrylic should be lasered with protective paper still on. Our piece had paper removed before we got it, but it scratched in handling. Also the vaporized acrylic can deposit on the non-etched surface. This can be cleaned using a soft scrub designed for light scratch removal.
  • Check cuts and etches using cardboard standins.
  • Always watch the cut – especially with cardboard. The burnt edges may have embers that continue to smolder, or burn outright.
  • Laser jobs always take longer than expected. Most of the work is in the setup, eg CAD work.
  • Laser rasters take a long time to run, plan the burn portions for efficiency, and have other productive work you can do while watching over the etch.
  • When assembling lots of pieces, more hands can be very helpful.

We have a Container!

We have talked about using containers to create our space.  Cole, Tommy and others have played with various designs on their own for a long time.  The Community Work Day folks have said we could put containers on their space.

Our First Container, at its old home.

So when Cole found a 40′ High Cube, Aluminum container on Craigslist Tuesday, I called.  Yesterday, I bought it. It is in great shape and already has two ventilation turbines installed. This will help keep it cool, especially down in the valley. It will be delivered to CWD’s Pu’unene location on Tuesday May 3. Exactly where it goes is still TBD, but we have strong opinions (there arent a lot of great options).

La'a Kea Community Farm Building

The idea is to get a second container, placed about 20′ to the side and roof these over. Then we can put rollup doors over the open area. The result will be similar to the La’a Kea Community Farm building recently constructed on Baldwin Ave, Paia. This one doesnt have the rollup doors.


So next week, we will have a container in which to meet on thursday. However, there wont be any power, etc so it will get dark real quick. The build out of infrastructure will happen over the next few months. Then we will have a real home! Yippee!!

If you have other ideas for tricking out the building, please post! and/or come and discuss.  Here’s an example I found via google search…

Paul Stankey container home outside of Duluth, Minnesota

April 21 meeting and Chill Box build night

We had another build night on April 21st at CWD Puunene.  We are progressing slowly. Cole and I arrived before 5pm to take over from CWD people.  They are putting in a security system in a week or three, and we should have our own access after that.  Meanwhile they are continuing to upgrade the building. There were a couple good guys in hazmat suits setting up to strip the lead based paint from the building as we arrived.

Early on, we had several people come by to chat. Amit stopped in after work to see the space and chat about the nice solar panel he is loaning us for the Chill Box project. Jim came with three nice big deep cycle batteries and a charger. Power system is shaping up! Matt and Patricia from CWD came in for a while to give support and chat. Later in the evening, Ben W came and spent a bit of time cleaning up the spam in our wiki.

As usual, here’s the flicker set:

[slickr-flickr tag=”April-21-2011ChillBox” descriptions=”on” flickr_link=”on” sort=”title” ]

Chiller System

Cole has been working on the chiller and container box. He got the hot side fan/pump and copper block attached to the peltier, and plumbing on the soil side.

There are several different sized fittings with the copper block, pump and pipes. The flexible tube we started with last week has been reduced to a few short pieces that help with the connections. The main soil section is now aluminum pipe. The metal helps conduct cold well, so we get good condensation and soil chilling. Copper pipe would be more conventional, but we were concerned about the copper affecting plants. Aluminum is a good heat conductor and less of an effect on plants. A T-fitting and valve lets us add water and bleed out air bubbles.

Cole picked up a small planter box and has been hacking away at making the parts fit. We need to work this fair bit to avoid kinks, and get the electronics into the package as well. We decided, at the end of the night, that a custom acrylic box would be much preferable. It will allow us to show off the setup and learn how to laser cut and fabricate with acrylic! Looks like more educational aspects of this project keep popping up!!

We did get the chiller fully setup and working on the hacked power supply. It chilled very nicely with condensation coving the aluminum quickly, and none on the plastic pipe. Then we decided to try out the 12v battery. We chose the big marine battery and it worked great!!


Jerry’s been working the electronics with parts arriving and code being written.

Cole ordered a RobotPower MegaMoto Shield to provide us with power control. The MegaMoto can be configured several ways and stacked for multiple motor controls. Each board provides up to 13A continuous power control with 30A surge. This should be adequate for advanced Peltier control, and also perhaps the pump systems. The MegaMoto looks like it will also be fun to try out on other projects later. 13A motor control on an arduino? Woot!

Power System

Amit has loaned us one of his Sanyo 205 Watt Solar Panels for the project. We should only need one of these but need to get a solar power charger/controller and some MC-4 connectors.

Sony HIP-205NKHA5 solar panel

came by after work to see progress and talk a bit about the solar panel he is loaning us. Jim came with a few deep cycle 12v batteries and a charger.

First meeting in Pu’unene space

We had our first meeting last night (4/14/11) in our new temp space in Pu’unene. Although there was a small turn out (5 total), I consider it a success. We did not so much talk about Makers, finding space, etc as we worked on projects!

Attending were myself, my son Brian, Cole Santos, Gabe Mott, and Matt Lane. Matt works with/for CWD (community work day) on their Community Garden project. He was basically stopping in after a full day in the field, but was happy to hang with us for a while. We chatted about the space, and potentials for container based buildings. We need to look carefully around the area in daylight sometime soon to see where we can site some – and get discussions going with CWD (and Maui Electric, etc) about this.

Here’s the full flicker setof images:

[slickr-flickr tag=”MakerMeet-April142011″ descriptions=”on” flickr_link=”on” sort=”title” ]

Cole and Chill Box

Cole had all the elements for his part of the Chill Box project. He was working on getting the cooling unit hooked up with new Peltier heat sink (water cooled hot side – awesome!). Unfortunately, the peltier we used last week didnt seem to operate. Perhaps we fried it without having proper hot side cooling? Fortunately, Cole just happened to have another peltier fridge in his car. Even though we lacked proper tools (gotta work on the traveling kits!) he hacked the peltier out and got it hooked up. It quickly made a very cold surface, so we put our water block on it and fired up the pump with hose…. oh yeah, filling the hose was not easy. Adding a T with a fill valve helped, but perhaps next time we do this step outside so as to avoid spilling water. We didnt have any heat conducting paste but the setup didnt do a whole lot to chill the water. Paste and a clamp will help but perhaps we have too much water/tube length. Perhaps a peltier just wont cut it… as people have cautioned us. Cole is going to look into a larger peltier and perhaps some DC compressor fridge/dehumidifiers.

JerryI and Chill Box

I, Jerry Isdale, got a bit of time to work on the SHT-11/15 Sensirion temp/humidity sensors we are using for Chill Box.  I found several sets of example code for running it on the Arduino. I found one from ?? that includes all the code with no C++ library.  The PracticalArduino site has a library based one (not mentioned in their good book). The Target23 example with library has some comm reset functions but needed some mods to the example to avoid name conflicts.

I had all sorts of problems not getting responses (error 1) from all the various PDE sketches.  After some close examination of the code I realized I had major operator failure – the data pins can be any of the 0-13 on my Mega board.  different examples had different values.  Once I synced up code with hardware, it works good.

I like the practical Arduino lib gives both F and C readings. I like softReset etc from Target23 lib.  I think we will create a mashup with assorted extra fixes when we put together all the code for Chill Box.

I brought the Vegitronix soil moisture and temperature sensors but didnt have time to try em out on the Arduino. I did find a project on web that shows how to use the moisture sensor.

I’ve also got some DS18S20 temperature sensor samples incoming (arrived as I wrote) from Matrix Orbital. There are some examples using this with Arduino. It uses a 1-wire protocol which lets you gang several sensors on one ‘network’.

A similar sensor LM-35, was used in an Instructable for underwater rov use. Technique looks like it could be used for the DS18S20.

BrianI and Arduino

BrianI (my son) worked on his arduino, and organizing his electronics box. He has the Arduino Experimenters kit and is learning (mostly self taught) how to program and wire up circuits. The kit is a decent basic intro to Arduino. It is available from several sources such as AdaFruit and Solarbotics for about $85. Documentation (experiments, etc) is available for download from the ARDx site (see links on adaFruit page).

Gabe Mott, ColorBox and Ideo Labs Kinect Physics

Gabe Mott, who is building the ColorBox, brought in his Kinect. There is a Kickstarter project to help fund some upgrades to the Color Box. Please help out! Earlier in the day we had found Ideo Labs Kinect Physics Demo. Its an OpenFrameworks based application with source available and supposedly could run on a Mac. I pulled down the FAT distribution of openFrameworks (of_preRelease_v0062_osxSL_FAT), which includes various addOns referenced in that article. Then we started trying to make it work in XCode…

My first test was to go into the ofxKinect/example (of_preRelease_v0062_osxSL_FAT/addons/ofxKinect/example) and build the application. After a minor bit of relearning to navigate Xcode UI, I managed to get the application running. We connected up Gabe’s kinect and Wow – it worked.

Next was trying to get the IdeoPhysics demo built. The blog page said it needed the ofxBox2d physics add-on as well as ofxKinect. I found that but had to renavigate XCode to figure how to create a new project with both app features.

Easiest way seemed to be to copy the example folder from ofxKinect to apps/myApps/IdeoPhysics. Then I opened the ofxKinect.xcodeproj file with XCode 3.2.5 and used Project->rename to rename it. (You cant simply rename xcode projects in finder as there are a bunch of internal vars/proprties that have to be changed.) The path depth (apps/myApps/IdeoPhysics) was needed to match addons/ofxKinect/example so relative path names inside the project still worked. The project rebuilt and ran identical to original – file moving worked.

Next I copied the 3 source files from Ideo’s googleCode release to the src folder in the project (overwriting the 3 files there) and rebuilt. First glance at the code indicated there were 4 image files used in the tumbling boxes, but these were not included in the Ideo repository. The code did not check for failure to load. I left this for now.

The compile first indicated the ofxBox2d addon code was not found. The ofxKinect example didnt use it so it was not linked into the project. I dragged the folder from Finder to the xcode project’s add-on group and trimmed out the examples folder.

Next compile indicated we were missing ofxTriangle and contourSimplify. I did a web search and found ofxTriangle as an addon. countourSimplify was a bit harder to find. After some digging I found the code over in Joel Lewis’s google code svn. There is probably a better link than that, but for now it worked.

Next up I got a whole bunch of errors about:

class ofxBox2dRect has no member named width
class ofxBox2dRect has no member named height

testApp.h defines

vector rects;

It seems that ofxBox2dRect does not have width and height members, at least as provided in v0062_osxSL_FAT. So I edited the ofxBox2d source In file ofxBox2dRect.h, after line 12, I added public variables:

float width;
float height;

then in setup() after line 31 I added:

width = w;
height = h;

and Eureka! it works!!

We bounced around some blank squares for a bit rejoicing.  Then Gabe made 4 colorful images and we dropped them into the project.  They needed to be located in bin/data so the app could find them when run.  And LO! we had bouncing colored boxes!

The four of us (Gabe, Cole, BrianI and myself) had fun playing with the app for a while. We noticed that when you go to full screen window, the boxes still (for most part) stop at the original bottom of the screen as if it was still there.

I transferred the code to Gabe’s Mac, and we rebuilt and ran it there – yippee it worked.

We cleaned up and packed ourselves out by about 10:15pm.

Some notes for future meetings:

  • bring full set of basic hand tools (screwdrivers, pliers, hammer, etc)
  • wear insect repellant
  • food will be attacked by ants
  • bring some foldup tables for added workspace, maybe some chairs

We have a space! Sharing with Community Work Day

Yippee!! We finally found a home.  Community Work Day has agreed to let us use part of their building in Pu’unene for work and meetings.  Later we can put shipping containers on the property and utilize those.

Community Work Day Site Entrance - right hand building is where we meet

The space is  located at E Camp 5 Rd, Kahului, HI 96732.  This is behind the mill near the Friends of the Library.  The road and location may not be in best shape, but the price is right – FREE!  Here’s the google map to location:

View Larger Map

Here are some more pictures of the building and the interior room we are using…

[slickr-flickr tag=”CWDSite” descriptions=”on” flickr_link=”on” sort=”title” ]

(see flickr set

Our first meeting in the space will be Thursday April 14 from 6-10pm.  Come One! Come All!!  We will talk about the ChillBox GGHC project, future classes, membership building, etc.

Maui Makers Needs New Logo

Ok, the turtle was picked a year or more ago by me – Jerry – as something simple and generic to denote Maui without getting too creative. I’m an engineerd not an artist/designer.  Now that its been in use a while, it is obviously in use elsewhere too. It is not distinctive enough to be *our* logo.  Several people have pointed this out – repeatedly. in less nice terms.

So ok, lets create a new one.  An idea I’ve had percolating around for a while was to continue with the petroglyph basis but add more Maker theme.  I found some human figures, some tool symbols, etc and started tossing them together in photoshop with my mediocre skills.  First I put in a wrench and the symbols for a laser and WiFi:

New Maker Logo with laser and wrench

Cole S. liked the basics but suggested an alternate:

Cole's version with wrench and proton canon

Brian T. suggested we use the symbol for a transistor instead of a laser. So I hacked one up:

Jerry's version with transistor

So now we turn to our community at large.  We need someone with some real design talents to tweak these (or come up with something entirely new).  It should be fairly simple so we can engrave it, make stickers, etc. It should be readable when scaled down and use minimal colors (B&W imho works just fine).


I played around a bit with the logo while making the acrylic for Chill Box and came up with this:

April 28th Maker Logo