Archive for April, 2014

Elephant

Marco/DIY3D mentioned the LeFabShop Elephant on the Makergear Google Group (defunct, now that MG started their own forum) and I had to print one for an upcoming presentation:

Elephant - on platform

Elephant – on platform

The leg shafts broke free after a bit of struggle and it now prowls my desk in search of handouts:

Elephant - standing

Elephant – standing

I like the semi-transparent crystalline effect of natural PLA, even if it’s not appropriate for an elephant…

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Headband Magnifier: Lamp Switch

One of my headband magnifiers has a headlight above the brim, an incandescent flashlight bulb powered by a pair of AAA alkaline cells, that hasn’t worked well since the day I bought it. This being a time of finishing small projects, I finally tore it apart and discovered that the cells and contacts were in fine shape (!), the bulb (remember bulbs?) worked, the wiring was OK, but the switch was bad.

Magnifying headband - lamp switch

Magnifying headband – lamp switch

The switch body seems to be firmly anchored in place, so I pried that red base plate off in situ, un-bent the silver-plated (!) spring-contact-actuator, and reassembled it in reverse order. No pictures, as it took less time to do than to tell, but it now works perfectly… most likely, for the first time ever.

Stop squirming! This can be much more painful…

Magnifying headband - in action

Magnifying headband – in action

I’m mildly tempted to hotwire the guts of a white LED flashlight into the thing, but that would require either another AA cell or a booster circuit and I’m not ready for that just yet.

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Bicycle Helmet Mirror Mount: Re-anchoring the Boom

My original dimensions for the helmet mirror mount used three sections of the inspection mirror shaft, with a short length of the fattest tube screwed into the azimuth turret:

Mirror shaft - 2-56 stud

Mirror shaft – 2-56 stud

Each section has a pair of brass leaf springs applying just enough friction to hold the next-smallest tube in place, with a rolled crimp securing the springs and preventing the smaller section from pulling out. My first version used that short length of the largest section and the next (for Mary’s helmet) used only the two smallest tubes; it’s rapid prototyping at its finest, except that I rarely discard a prototype that actually works.

Late last year I managed to pull the shaft out of the base while adjusting the length and watched those two springs flutter to the ground beside me.

After finding both of them amid the usual roadside clutter, I swore a mighty oath that I’d epoxy the base of the middle tube into the larger one, eliminating one non-functional adjustment point:

Bike helmet mirror mount - epoxied stalk base

Bike helmet mirror mount – epoxied stalk base

The heatstink tubing covers most of the evidence, but you can see a fillet of epoxy around the end.

Done!

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Old-school Lecture Hall Illumination

We attended a talk in the Taylor Hall Auditorium at Vassar College, which features lovingly restored lamps that illuminate the pull-up desks on each seat:

Vassar Taylor Hall - desk lamp

Vassar Taylor Hall – desk lamp

The housing consists of black-painted cast iron, with a 7 W (“Christmas tree”) incandescent bulb keeping it pleasantly warm to the touch. A metal conduit connects the lamp to the main conduit running parallel to the seat rows at the edge of each step. Another hole on the other side cast light upward toward the ceiling, perhaps providing general room light in the Good Old Days.

The restored seats are much wider than dictated by contemporary standards, perhaps allowing enough room for the classic conical skirts often seen in historic Vassar photographs:

Vassar Taylor Hall - desk lamp perspective

Vassar Taylor Hall – desk lamp perspective

That’s about 170 W of light down those two rows. I didn’t think to run the numbers at the time, but there’s gotta be a kilowatt of those little lamps in that auditorium!

And, yes, male pattern baldness affected a remarkable number of attendees…

 

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Waterless Urinal Target Redux

Spotted this (so to speak) on a journey:

Falcon Waterless Urinal -seashell target

Falcon Waterless Urinal -seashell target

Evidently, the bee is out and the shell is in…

Some backstory fills in things I never knew about the subject. There are, of course, lawsuits.

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Water Heater Anode Rod Status

The Whirlpool water heater anode rod is corroding nicely:

Whirlpool anode rod - 2014-04

Whirlpool anode rod – 2014-04

The new GE water heater anode rod seems to be passivating:

GE anode rod - coated - 2014-04

GE anode rod – coated – 2014-04

There’s some corrosion up near the bolt head, so it’s not entirely asleep:

GE anode rod - bolt - 2014-04

GE anode rod – bolt – 2014-04

I hammered the coating off the rod, scuffed the shiny parts with coarse sandpaper, wiped off the dust, and stuck it back in its socket. We’ll see what it looks like next year.

Both tanks flushed nicely without too much sediment.

Searching for “water heater” will turn up other posts…

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Incandescent Bulb Lifetime

Two 40 W incandescent bulbs in the front bathroom burned out within a few days of each other. Being that type of guy, I know that I installed this bulb nine years ago:

Bulb base - install date

Bulb base – install date

The date is easier to read with the bulb in hand: 13 Feb 05. The (5 yrs) indicates the previous bulb in that socket lasted five years.

The other bulb date went in during March 09, so it survived only five years; the previous bulb lasted 6 years.

Even though 40 W incandescent bulbs are history, maybe I have enough spares on the shelf that the next owner can replace ’em with cheap LEDs.

This may not be science, but it does have numbers…

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