Free - Foundations of Mechanical Accuracy

On Thu, 18 Jan 2018 16:53:24 -0400, Leon Fisk


Thanks, Leon, I'm sure I will.
--
Ed Huntress

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 18 Jan 2018 16:53:24 -0400, Leon Fisk

Yeah, the new "techs" are board replacers because the computer diagnostics told them to do so.
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

In 1970 the Army trained me to repair computer communications 'peripherals' to the component level after memorizing the machines' operations, but the material was so difficult that only students with science degrees completed it. Four of us survived the forty week course, whittled down from over 80 entrants. We were available only because the grad school draft deferment had been dropped.
The Army was soon forced to revert to a test procedure for board swappers. I think the problem was that people who could do it were qualified for better jobs. I certainly preferred designing and building new equipment over repairing older stuff.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 20 Jan 2018 08:33:05 -0500, "Jim Wilkins"

Wow, large drop rate. I learned the basics at Coleman College, but only stayed working in the field for 3 years. That means I don't have a firm background in it, unfortunately, and can't look at a circuit on the PCB and tell you what it does and how. :-( SKS bought the company I worked for and moved it to Sandy Eggo, changing my 11 minute commute to over 2 hours per day. I took the separation package.

Good for you, and I can certainly understand your preference. Who repaired the boards, or did they? That would be good stock to help turn the board swappers into real techs.
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

AFAIK we were trained to the Depot (highest) level although we didn't have comparable test or soldering equipment, if any, in the "field", more often a forest. In fact during Vietnam Europe was starved of everything, we couldn't even get wiper blades etc for Jeeps and kept about half our allotment of them running with personal purchases from J.C.Whitney, which resulted in dangerously overpowered engines and numerous roll-overs on winding back roads better suited to the Ultimate Driving Machine. Most soldiers didn't go off base and thus had money to burn.
Testing has evolved in the direction of not requiring expert operators, it leverages the knowledge that designed / debugged the prototype. http://www.4pcb.com/pcb-electrical-testing.html
The Golden Board test is a good example. It and the Device Under Test are driven identically in parallel and the test station or operator looks for differences. The test station designer (me) needs to provide a black-box imitation of the rest of the system.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 22 Jan 2018 07:28:26 -0500, "Jim Wilkins"

State-of-the-art stuff. Is there a rule similar to Moore's Law for tech? Everything has made fantastic jumps since I was playing around with it in the late '80s, that's for sure.
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Once tech reaches Good Enough the improvements slow way down. Maximum CPU clock speed leveled off around 4 GHz quite a while ago. https://en.wikipedia.org/wiki/Comparison_of_Intel_processors
I doubt most people would recognize a Boeing 707 airliner or an F-4 Phantom fighter built in 1958 as being a quaint half-century-old antique, and today's models aren't even faster. -jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Here's a great talk about Moore's Law that also uses a long detailed aircraft history analogy to talk about that "Good Enough" barrier:
http://idlewords.com/talks/web_design_first_100_years.htm
A quote from the middle:
These are the victories of good enough. This stuff is fast enough.
Intel could probably build a 20 GHz processor, just like Boeing can make a Mach 3 airliner. But they won't. There's a corrollary to Moore's law, that every time you double the number of transistors, your production costs go up. Every two years, Intel has to build a completely new factory and production line for this stuff. And the industry is turning away from super high performance, because most people don't need it.
Certainly the first half of if it is going to be relevant to people not in the original audience of web designers. The author has a smooth insightful way to mock things.
Elijah ------ one of the newest talks compares ham radio to the internet
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Those were certainly the long and the short of it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 22 Jan 2018 19:05:17 -0500, "Jim Wilkins"

Love the 2045 blurb: --snip-- And if you think that the purpose of the Internet is to BECOME AS GODS, IMMORTAL CREATURES OF PURE ENERGY LIVING IN A CRYSTALLINE PARADISE OF OUR OWN INVENTION, then your goal is total and complete revolution. Everything must go.
The future needs to get here as fast as possible, because your biological clock is ticking!
The first group wants to CONNECT THE WORLD.
The second group wants to EAT THE WORLD.
And the third group wants to END THE WORLD.
These visions are not compatible. --snip--

If they're doing it now, they likely have the most advanced AIs in existence and are predicting human behavior, investing in up and coming market trends. Wall Street and D.C. would pay a bundle for one.

Waves?
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

https://www.technologyreview.com/s/415041/new-measure-of-human-brain-processing-speed/
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 25 Jan 2018 07:16:27 -0500, "Jim Wilkins"

OK, for words, that may be one measurement. The test was for "lexical decision tasks". What about identification of threats? Smells? Too bright of a light? Now watch this guy shoot 2 balloons in 0.02 of a second. Tell me how many synapses fired to make that happen.
https://www.youtube.com/watch?v=hujvVmuLuoM
Jerry Miculek can draw, aim, & fire 8 rounds on multiple targets in under a second after identifying a beep. How many synapses?
https://www.youtube.com/watch?v=ChSazF41q-s
Cupstacking, anyone?
https://www.youtube.com/watch?v=EJu5MZfSvBE
So, obviously, there are differences in mental/physical task speeds. I lean toward thinking that the brain works in the megaflop speeds, myself.
As Moscoso said at the end, when he saw the article, he doesn't think there's an upper limit, even in the lexical realm.
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote in message

https://en.wikipedia.org/wiki/Speed_reading
http://bigthink.com/endless-innovation/humans-are-the-worlds-best-pattern-recognition-machines-but-for-how-long
.-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I was working in the semiconductor industry when surface mount came out. Circuit board layout became much simpler without the forest of vias to dodge, especially for inner signal layers on increasingly dense computer boards. That soon translated into physically smaller but equally challenging designs.
The pads for drilled holes had to be excessively large to avoid misalignment between the photoetched copper and the separately drilled holes. They are drilled in a stack and the glass fibers randomly deflect the tiny bit as it goes deeper. Boards were rejected if there wasn't a minimum ring of copper all around the drill hole, because it wouldn't plate all the way through reliably. The hole is drilled larger than the specified finished size to allow for plating.
It was recognized that surface mount boards may not be repairable but the greatly reduced manufacturing cost balanced out the high price of qualified repair technicians, the overhead of handling returns and the higher potential of subsequent failure on hand-reworked boards.
Typically a small subset of boards caused repeated trouble while the rest worked fine until obsolete. About half the field returns I tested showed no fault on my test system.
I buy, recondition and use older lawn and garden equipment because it's made of metal that I can repair or copy instead of molded plastic I often can't. Yesterday I forged a pair of long canning-type tongs from 1/4" gas welding rod to handle firewood for the stove.
The kitchen tongs I can buy don't last long. Fireplace tongs are intended to grab the middle crosswise rather than the end lengthwise.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 01/18/2018 02:53 PM, Leon Fisk wrote:

I recently repaired a printer for a neighbor -- fixed a mechanical problem with the paper feed deep inside the printer. Neighbor said I should go into business repairing printers. I pointed out that for my time at minimum wage I would have to charge twice what a new printer would cost.
--
Bob Nichols AT comcast.net I am "RNichols42"

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 21 Jan 2018 19:44:53 -0600, Robert Nichols

That's something that a lot of us overlook. And that's why we aren't rich. d8-)
--
Ed Huntress

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I factor in the knowledge gained from fixing something I didn't previously understand, if relevant to the stuff I own or want to buy.
For example the repair instructions for the HP6110 3-in-1 printer I was given say to swap it for a less troublesome newer model, but I found that Mass Air Flow Sensor cleaner works fine to restore the clouded front surface mirror.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 17 Jan 2018 13:21:10 -0400, Leon Fisk

I've been a fan for awhile now, thanks to you.

"Can I get it on my phone?" LOL

Yeah, that's fun.
-
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 17 Jan 2018 09:28:56 -0500

Here is a regular search I use to do every week or so:
http://archive.org/search.php?query=title%3Acatalogue%20AND%20-title%3Acourse%20AND%20mediatype%3Atexts%20AND%20-scanner%3Agoogle%20AND%20-subject%3Acollege%20AND%20-subject%3Aart%20AND%20-title%3Auniversity%20AND%20date%3A%5B1800-01-01%20TO%201941-01-01%5D&sort=-publicdate
I gave up when they dropped the djvu document format. It would show me all the recent old catalogs that had been uploaded. I've saved many of them through the years. Here is a new one:
https://archive.org/details/ArrowTools1920Catalogue
The last few pages of items has old tool steel lathe cutters. I like to see what shapes were used back in the day and that is a nice set with descriptions :)
--
Leon Fisk
Grand Rapids MI/Zone 5b
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 17 Jan 2018 11:02:07 -0400, Leon Fisk

Cool stuff. I'm going to have to learn how to use this thing. I only came across it a few weeks ago, and have explored it a bit by way of the collections.
Thanks for the tips.
--
Ed Huntress

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.