Sunday, May 27, 2012

To Case, or not to Case?



To "case" or not to "case"?  That is the question that a few hundred million people have to ask themselves each year, in relation to whether to protect their new smartphones.

The case for a case

The stance to put a protective case on a smartphone is generally taken by those who view the risk of damage as a losing proposition.  These folks fear that they will inevitably drop the phone with such destructive force that it will suffer damage from which operation cannot continue, generally, in the form of a cracked touchscreen, as seen below.
iPhone 4 - cracked front.  Works, but is a challenge.

It should be noted, however, that a smaller portion of the "cased" crew prefer to use a covering for their phone to express their sense of style, taste, or distinction.  Sometimes their sense of "good style" is debatable.
Personalized cases abound - but they aren't always elegant.


The case against a case

Many smartphone users choose to leave their phone in its natural state, unblemished by plastic housing.  Their primary concern may be appearance of the phone, and a secondary appearance is any cruft (crumbs, dirt, sand) that become trapped between the phone and the case, often still visible to the user.

Oakley’s ridiculous iPhone case: "If you’re ready to go mobile with some style, this is the case you’ve been looking for."  Are you JOKING?!

It should be noted that a huge savings in thickness presents itself, and the resulting pocketability (insertion and removal from pants pockets) is undeniable -- often the reduced pocketability is the number one concern of case users (citation needed ;-).  Pocketability is determined both by the ratio of thickness of hand + phone to the size of pocket entrance, as well as the materials used, and their static coefficient of friction.


The case for an anti-case: BEZL

A new 'case' is on the block and serves to address both the visual signature as well as usability and protection aspects of case debate.  The BEZL is a set of four corner bumpers that protect the phone when dropped onto flat surfaces, such as countertops, flooring, and parking lots.

Aesthetically, it's the most unique case I've seen, in that it expresses some appreciation of the beauty of the phone design itself, as well as protection from drops, while retaining ease of use (finger swiping between any two phone edges, and pocketability).  I believe there's plenty of room for phone personalization, between the empty back of the phone which could hold a graphic layer, and the bumbers have room for symbols and bedazzling, as desired. ;-)  Here's a product video:




Drop test of the prototype - I hear that Jos has dropped it over 20 times onto concrete, much to the surprise and slack-jaw of the Apple store employees!

Here's the application of the adhesive bumpers:


Go get a BEZL!

Monday, April 30, 2012

Thermal Solar Pool Heater - summary

Since there's plenty of interest in the thermal pool heater that we made last summer, I thought I'd try and do a post just to summarize what we're using, and how it's holding up.  (My original post is here.)

Here's a silly MS Paint schematic of our system:
Simple schematic showing intake, pump, coils (2xparallel of 3 in series) and return.

Main components are the coils and pump.  The pump was picked up off this surplus site is:
Diamond brand; Model No 312233-01; Consuming 120 Volt and maxing at 7 Amps (nameplate), yielding 1/2 HP, in a CSA Enclosure 3, Made in Italy.  I see that it's available as of 04/30/12 for $95, though I seem to remember paying less.
This pump is MORE than enough power, but with two smaller pumps, we didn't quite have enough juice, so we figured we'd go a bit overkill on this one.  For those wondering, we don't submerge this pump, but rather, it sits by the side of the pool, and so the electric cord (which goes through a watertight gland) doesn't come into contact with the pool water).

Our roof is about 15 feet above the pool water level (note that we crest the apex of the roof, and the coils are on the far side, for sun exposure).

The pump is controlled on a time-of-day timer, though someday I'd like to trigger it with a light-activated system, or possibly a water-temperature-activated system.  On cloudy days, I try and remember to flip the switch on the pump itself, to prevent it from cooling the pool.
The timer is an all-weather system, with a rain/splash guard, not meant for submersion.
The one I bought is $11 from Amazon, click here to see it.
 The coils are arranged into two banks of three coils in series, the banks are in parallel, to slow the flow of water somewhat, to increase heating.  Our flow rate is measured at 15 L/min which is almost 240 gallons per hour.  In the summer, I've measured the temperature from the roof at over 130 F during startup, and continuous around 110, while incoming water is 80 degrees, so I don't feel the need to slow down the flow.  The coils are detailed in my past article, but since posting there, We spray painted the PVC pipe black, as well as the zip ties, to reduce with UV exposure weakening.  Also, a commenter recommended making the PVC crosses at different diameters (6 inches per side), so that it's easier to thread the flexible pipe onto the coil.  LOVE that idea, thanks Ariel!

What we failed to do was to glue the straight PVC pipes into the joiners at the middle of each coil, so that when we went to reposition them a bit, the coils became un-attached.  So if you do this, go ahead and use a primer and glue for PVC.  Totally easy, and worth the $5.
All of the water-filled connections are holding up just fine after all that daily cycling.  I had serious doubts about the push-to-seal type of joints employed by this pipe (remember, it's DIG corp, SKU # 642176 at Home Depot, $80 for 1000 ft).


Finally, go check out the 

Separately, we have a photovoltaic (PV) solar panel powering an attic fan to keep the attic cool in the summer.  This is a related effect to the above project, where the cool water from the pool actually cools the roof as well.  Bonus!  We enacted both projects at the same time, so it's hard to say which had a larger effect on the summer temperature in the house, but I would bet money that the fan had a larger effect -- it was noticeable.



A Moveable Feast rides!

As I mentioned in an earlier post, I've been helping out with a friend's project to build a kinetic sculpture based on Ernest Hemingway's "A Moveable Feast."  While it's been a few months in the making, this past weekend we finally did our first public ride, complete with a full brunch course!  Here's a few photos and titles to give you the gist of things!

Here's the under-carriage showing how the 3 people on each side contribute to forward motion.


This is the rear end of the machine, showing the leaf-spring suspension, drive chains, and transmission/differential.

Here, OS is hanging and lighting the chandelier!

We decided to enter the Moveable Feast in the Pasadena Doo Dah parade, on April 28, 2012

We appeared at the end of this CBS news segment:

Once we arrived at the parade and set the table, the photographers couldn't get enough!
Underway, with a stilted-spectator, and the parade fans.
This gives an idea of the peddling, size of the wheels, etc.

Celebrating a wonderful morning brunch, with the fans!

We ended up winning the only award in the parade: the Czar's Trophy for Best Overall Entry!