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Michael Ackerman
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My notes on the benefits of continuous motion escapements for wooden works #clocks   .

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Conical Pendulum Clocks have continuous motion escapements. They don't tick. I got interested in them after seeing wonderful wooden-geared clocks. These clocks tend to be based on John Harrison's grasshopper escapement, and though the grasshopper is famously low-friction, builders still have trouble making them work. Even if every gear tooth is painstakingly sanded smooth, the clocks will need to power past the roughest spot.

I believe that continuous-motion escapements like conical pendulums are ideal for wooden gear clocks. When the gears stick, the pendulum will press against the back side of the horizontal arm, unsticking them. Has anybody made a conical pendulum clock with wooden gears?

Note the difference between this escapement and the flyball telescope clock drives I wrote about in my earlier post: https://plus.google.com/102702523678372583669/posts/ap8RiRKkdNz The conical pendulum pendulum here will keep good time regardless of the pendulum's swing, provided that it is "reasonable small." The flyball telescope drives, though, depend on braking devices to keep the pendulum's height at a specified large angle, around 45°.

The horizontal gearing shown here is similar to that in the Briggs Rotary Clock: Briggs Rotary

It (correctly) has the small angle used in clocks made by Farcot: The Paris Exhibition Clock by E. Farcot

Here are photos from a discussion post which show how a contrate wheel (crown wheel) attaches the horizontal arm to the vertical movement: http://mb.nawcc.org/showthread.php?20858-Post-Your-Farcot-Clocks-Here&p=237589&viewfull=1#post237589 . I saw another which accomplished the same thing with a worm gear.

Ken Kuo made this video. Many other escapement simulations are on his YouTube channel, including some ones I've never seen before: https://www.youtube.com/channel/UC2h07cGBpJs8bF3OkgtJICg

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The Softalk Apple Project will explore this wonderful magazine from the 1980s. I really enjoyed Softalk, especially the Assembly Lines articles, which taught you how to write assembly-language routines to speed up your BASIC programs.. Most of it was non-technical. Really great stuff.

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This is a restored clock drive from a telescope in Rhode Island. Compare it to the original flyball governor from the 60-inch telescope at Mt. Wilson Observatory: http://www.oldengine.org/members/levans/60clock/ Even better is this photo of the 100-inch telescope's clock. Note the telephone at the bottom for scale! http://hdl.huntington.org/cdm/singleitem/collection/p15150coll2/id/1461/rec/4

Similar mechanisms have  been used to turn the huge lenses in lighthouses. I'm not really sure that this qualifies as a "governor" since it doesn't actuate a throttle or transmission; it simply dumps excess energy into the braking device. Also, why does it hit the braking device instead of merely rubbing against it, as in speed controllers from wind-up gramophones? In the Mt. Wilson clock drives, it appears that a brake brushes against the polished ring at the top.

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Well, I found Paso de la Tijera, and it doesn't mean Pass of the Scissors after all.

The link below is one of the several maps at the Huntington which mark the location of "Paso de la Tijera" but I found this one to me most detailed. It identifies a spot where a path crosses a stream, just northeast of the Tomas Sanchez house. According to California's Spanish Place-Names: What They Mean and How They Got There by Barbara and Rudy Marinacci, the word Tijera almost always means "drainage ditch" in old land descriptions. This particular map also notes: "Dry Place."

So where is it? It's at the intersection of Crenshaw Blvd. and Martin Luther King Jr. Blvd. Few of today's streets align with the roads on the old map; two blocks of Stocker are the remnant of the long road which stretched northeast from the Sanchez house. The diagonal part of MLK Jr. Blvd. was once part of a longer, straight ditch which drained the swampy area to Ballona Creek. The "Dry Place" is now Baldwin Hills Crenshaw Plaza.

Of note- one building on the Sanchez homestead is still standing and is a contender for the oldest building in Los Angeles.

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Where is the Pass of the Scissors? La Tijera Boulevard is one of the main streets in southwest Los Angeles. Its name relates to an 1843 Mexican land grant, Rancho La Cienega o Paso de la Tijera, "Ranch of the Swamp Or Passage of the Scissors."

Many sources say that the pass is a crossing of the Baldwin Hills which resembled a pair of scissors to early Spanish settlers, but I haven't found a reliable description of its exact location. My surmise (and one in the link) is that it is at the intersection of La Brea Ave. and Stocker Street. A look at a topographic map shows that there is a pass at this spot (though it's unnamed) and looking north the two streets descend through separate, deep canyons which could be the scissor blades.

Also, La Tijera Blvd runs directly toward this spot, though it ends where it hits the oil fields.

Can't we get this spot marked on a map, people?

I'm a little sad that GoneToPlaid has taken down his YouTube videos. Hope they come back in some form. Here's his web site: http://apollo.mem-tek.com/  [Edit] Jumped the gun a bit: GoneToPlaid Gone. Well, not completely.

I've been pondering the number 4/3 in the formula for the volume of the sphere. Anybody else find it a funny number in such a basic equation? It appears to result from the choice of the cube with a unit edge as the standard unit of volume.

There are good reasons the cube shows up in nature and engineering, but I'm not convinced that it's the best unit for expressing volume, at least in basic Algebra.

Why not state volume in units of a tetrahedron with unit base edge and height, and unit thickness? (i.e. one-sixth the volume of the cube.) Accordingly, the unit of area would be the triangle with unit base and height. (i.e., half the area of the square.)

Yes, it's "always been done that way" but it might help students focus on logic instead of getting bogged down in arithmetical drudgery.

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Stanford's collection of maps depicting California as an Island makes interesting viewing. The coast is captioned with familiar landmarks like Point Conception and Catalina Island, up through Cape Mendocino and Cape Sebastian (I've visited the latter: it's stunning.) But these familiar places end abruptly at Cape Blanco, (Southern Oregon) where the coastline apparently hits the Strait of Juan de Fuca. At least that's what Wikipedia says. California's Northern coastline contains the unfamiliar placenames Tolaago and Estiete. No evidence of the Columbia river.

I did learn that Point Mugu was formerly called Point Conversion. There are a staggering 700+ maps available for your bemusement. http://news.stanford.edu/news/2012/august/california-island-maps-083012.html
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