Monday, February 15, 2010

Custom Built Reading Lamp

I've been wanting to get this written up for a while now.  Sometime last October I was having a less that perfect day and stopped by Lowe's on the way home to hunt around for a couple of pieces I had been wanting to get for a lamp I wanted to build.  I picked up some 8x10 sheets of clear lexan, a copper post cap, some copper tacks and headed home.  Then I set about scrounging up the parts I needed to build the frame for what is pictured below - a sort of lantern style table lamp.


I took a piece of red oak I had left over from making a bench seat and squared it up with the table saw.  Then I pulled out an old piece of quarter round left over from making my root cellar and used the table saw again to segment it into four 10" pieces and then put slots for the windows in them.  These went together with a spacer made from 1/4 plywood which I had used to line some cabinets with.

To make the corner notches, I just set the rail on the table saw the width of the quarter round away from the blade and then cut the corners by flipping the piece over and rotating it 90 degrees each time.

I also used the table saw to size the lexan sheet.  Lexan is very hard and tends to chip, so I had to go slowly cutting it.  The top spacer was made the same way as the bottom but has one side cut short to allow the lexan on that side to be pulled up to maintain the bulb.  The quarter round was toe-nailed into the spacer with a nail gun and then glued with Tight Bond III wood glue.  This assembly was clamped and glued to the heavy oak base.  The base, I should mention, almost broke my hand.  I was drilling it with a flat drill bit on the drill press and had forgotten to clamp it down.   BAD.  At one point the bit locked up in the wood and it turned into a whirling wheel of death giving me some pretty awesome sub-dermal abrasions and bruises.  If I had decided on a rectangular base, I would probably have a broken hand or wrist.

Update 2/23/2011 - The Lexan has had a rattly sound in the slots for a long time, making the lamp noisy to turn on and off and seem cheap and fragile.  The other night I put a dab of hot glue in each corner inside the lamp where the lexan fits into the slots, top and bottom.  The whole structure is much more solid feeling now and sounds a lot more stable and sturdy when turning on and off.


I had most of the wire and couplings on hand, but bought the switch and the socket.   The switch was a threaded push button model so I was able to tap the oak with my tap and die set to accept the thread on the switch.  I thought that was pretty cool as it made for a very snug fit.  The cord was salvaged from an old alarm clock, which rests in pieces in a cardboard box on my desk with an array of other discarded items.

I soldered couplers onto the wires and crimped them.  The couplers are friction fitting and set up pretty tight when you jam them together.  Not wanting to expose the dust bunnies to the raw ends of the couplers, I sealed all the connections with some multi-temp hot glue which has to get pretty hot to melt and is generally non-flammable at low to moderate temperatures.  It does however seep into all the crevices, making an air and water tight seal.


The wood lamp frame was given a once over with some ebony polyurethane.  The lexan was treated with a coat of Testers Dull-coat spray to create light diffusion.  I tried a number of approaches to diffusing the lexan and the Dull-coat was the most uniform.  Plus, it can be cleaned off the lexan with goof-off or similar if I decide to try something different.   I put some of the copper tacks in the base for accent - not much but a nice touch, and then seated the copper cap on top.  Last of all I glued some sections of corner molding on the bottom of three corners to make feet to match the depth which the switch protrudes from the bottom.  This also allowed the wiring to not be crammed into the base but just tacked to the bottom with hot glue.  I had wanted to use white LEDs for the light element but wound up finding a 3 watt florescent tube bulb that was the same wattage and better illumination once it warms up.  A socket extender helped loft it into the middle of the lamp cage. 


I'm pleased with the final result.  Things I would do differently next time: pick a switch with less mechanical resistance.  I would also frame the lamp differently.  This thing is not going to suffer much abuse as built, but it looks nice.  I would make the top and bottom spaces thicker and dove-tail the rails into them for a solid fit.  I would also probably try to get tempered glass.  The lexan is fine for what is essentially a prototype, but it rattles and sounds cheap, and scratches easily.  I might also try to incorporate some brass next time.  Tempered glass and brass have a complimentary look to my eye.

I really enjoyed this project.  It gave me a lot of tiny challenges to figure out how to get certain things accomplished and let me put some of my meager skills to use which normally don't get a workout.   With a simple table saw, clamps, wood glue and some creativity, I think this project is doable by just about anybody.  Just be careful with that table saw (and the drill press!!).

Sunday, February 7, 2010

Get that dust out!

I was *this* close to getting a new computer this weekend.  Then I remembered some advice a friend of mine had given me that I had just recently passed on to others.  If your computer is very slow as of late and it once performed very well, don't just blame Windows or a fragmented hard drive.  Check the dust bunny quotient.

I tore my computer down last night and found: dust caked on the CPU cooling system, dust caked on a memory stick, dust all over the fans.

Dust on the fans makes them less efficient due to drag.  Air moving over the blades of the fan is slowed, reducing the amount of hot air, and hence heat, which can be displaced.  Displacing heat from your computer is essential to keeping the chips running in peak condition.  Too much heat in the chips causes electron flow to literally slow down as resistance is increased.

Dust on the heat sink for the CPU also contributes.  Not only can the fan not move air past the fins on the heat sink if dust is in the way, the dust acts as a blanket helping the heat sink to retain more heat.

Now this one I did not expect.  Dust on my memory sticks.  The fan for the CPU in my setup blows right on a memory module.  Dust was caked up to the point that I suspect it was causing a short on the surface  - just enough for the module to test bad on Boot.  So, after cleaning it, I got half my Gig of memory back!

To clean my system, I used the soft brush attachment for my vacuum cleaner AFTER removing the components from the case.  Trying to put a vacuum in your case could damage things, so be careful in there!

Happy computing!