Wednesday, November 30, 2011

Flo's V8 Cafe

So my son wanted a Cars 2 birthday party.  We went and bought plates and napkins with Lightening McQueen and all the other characters on them.  We made some games, and put up decorations. One of my tasks for the decorations was to make a sign for Flo's V8 Cafe to put by the food.  Well the sign in the movie (and at the Disney attraction) is a neon one, and a plain copy drawn on paper just wouldn't do.  So I picked up some EL wire and made a copy of the sign that lights up.  It was a pain in the ass to do, but everyone loves it and it was worth the effort.  Here's a pic of the sign from the Cars attraction at Disney Land
Here's a pic of my sign.

I think my version is a pretty good copy.

So how do you go about recreating a neon sign in just a few short days?  Well, I'd love to have the workshop and skills to make it out of real neon tubes and such, but no such luck on either count.  What I do have is some electronics background, mat board, poster board, cross connect wire, toothpicks, an awl and a source for some EL wire.  First order of business was to draw out the basic shape of the sign

I'd love to say I drew that freehand, but I cheated and used a projector and traced it out.  Next task was to find something to use in place of neon tubes.  EL wire was the obvious choice.  I ordered up some pink and aqua to match the photo of the real sign from Disney Land.

And this is how it looks when it is turned on.  It looks much better in the dark.  The party is at night so it works out well.

What I didn't realize until after the order came in was that I needed more wire than I had bought.  It comes in 8.2 foot sections, clearly that should be enough for this small sign, right? Wrong.  What I should have done before finalizing the order was to estimate the actual length needed.  I did this once the wire came in and I planned out the wiring path.  I was about 2-3 feet short.

So I ordered some more pink EL wire and got to work laying out what I had on hand.  I poked holes in the mat board with the awl and fed the wire through and shaped it to match the sign.  I poked smaller holes along the path of the EL wire to use to secure the wire to the mat board.

Once I had a section laid out how I wanted, I looped some small copper wire (any wire would have done, but I have several spools of cross connect wire on hand that worked well once stripped of the insulation) through the small holes and around the EL wire.  On the back I tied the copper around some toothpicks to secure the location of the EL wire.

Once the wire is secured on the back, it holds the EL wire firmly in place on the front side.  You don't really notice the small loops of copper wire when the sign is on.  If it bothers you, I'm sure that mono filament fishing line or something like that would work as well, but the wire is easy to tighten by simply twisting it up instead of having to tie a bunch of small knots.  I had thought of using zip ties, but they are very wide in comparison and would have been visually distracting.

I wasn't able to do the whole pink portion with what I had on hand, but the sign was definitely turning out well.

I got more pink in the mail and finished up the rest of the sign in the same manner.  The final result turned out great.

Monday, October 24, 2011

Air rockets!

So this past weekend I built an air rocket launcher with the kids.  I got the plans from MakeZine and got the parts from the local hardware store and from Amazon.  I modified the plans a bit, and generally used them as guidelines and used what I could find in the hardware store and made a few improvements along the way.  I added a schrader valve directly to the air tank and also added a pressure gauge so I could dial in the pressure for each launch.

The valve is the same sprinkler valve as in the plans.  I used two 9 volt batteries in series with a momentary switch on a long wire for the release.

The results were great.  We turned many heads in the park when we were launching.  With each launch I turned up the pressure to see how high we could send the rockets.

A few burst because of the high pressures.  The rockets we made did not have tape all the way around the tube body, leaving a spot for the rocket to burst.  The next batch of rockets we make will be taped all the way around to avoid this failure mode.  It was a lot of fun and fairly inexpensive at ~$20-30 for the total build.   The sprinkler valve was the most expensive part at $12 from amazon, the rest was the pvc and the gauge.  I had a handful of 9 volt batteries around, had the pvc primer and cement from an old plumbing repair a few years back and dug the switch, cross connect wire and small piece of perfboard out of the junk pile on my electronics bench. I may rebuild the trigger switch to be a nice hand held thumb switch or make a box to hold a plunger type switch, but those would just be for show, it works great now.

And a quick change of the rocket launcher tube and I have all the makings of a nice potato cannon, but that'll be a project for when the kids are a little older.  The rocketry was fun, but who doesn't like shooting stuff with a cannon you made your self?  I can't wait to bring this out in a few years with a new front end for launching projectiles instead of rockets.