Saturday, June 18, 2011

The Sun Never Used To Set On 'Em

I quote:
We still send imperial based tools all over the world,there are still old DeHavilland bi planes flying in New Zealand and Australia,we've sent whitworth and BA sockets or spanners to aviation museums from the UK to USA and railway engine enthusiasts from Darlington to Darjeeling.There are countless examples of British engineering over fifty years old still working or being lovingly restored in the most unlikely places.There once was a 'Great' Britain.
Need a Whitworth spanner? They've got 'em.

(Bumped into this site on a Wiki-wander on the topic of the standard threads for microphone stands. Here in the 'States [and mostly up Canada way], you'll find 5/8"-27 UNS; RCA was fond of 1/2" [or was it 3/4'?] water-pipe or conduit thread. The rest of the world, claims the mob-edited encyclopedia, is like as not to be using 1/4 or 3/8 BSW. Since those Whitworth threads are, except for thread profile and angle, twins to the selfsame size of SAE hardware [1/4-20 and 3/8-16], they seemed a little light to me. And what do the Russians use?)


Justthisguy said...

I betcha Whitworth fasteners of an equivalent size are stronger than the American ones, they having rounded edges on the threads, and thus smaller numbers for stress concentrations.

Oh, how I miss my "Machinery's Handbook!"

Anonymous said...

Whitworth threads are stronger, but the increment in strength is less than the increment in cost to cut them -- the more-complex shape means a Whitworth tap or die has to be tossed out when a "standard" one is still going strong.

Russia is more like Brazil than anything else. Their mode of industrialization involved isolated pockets, often enough set up by foreigners, and stuff made in one factory may not be very similar to that produced in another. Russian stuff is full of English-standard fasteners. They may call a tripod screw 6.4 x 1.27, but 1/4-20 is what it is.

Bubblehead Les. said...

As anyone who's worked on old British Motor Cars can tell you, Whitworth Threads are Okay, but tend to be a little "Leaky" regarding Fluids. Just be glad we don't have to deal with Lucas-Type Electrical Systems, also known as "%#%^YTV GFTUR^& why won't you WORK!?"

Roberta X said...

People keep telling me that. I've owned 2 1973 MGBs and an '81 Jag XJ-6. Lucas electricals all over 'em and never had a problem I couldn't solve, usually pretty simply. (No, wait, I had a distributor fail mechanically and we had to go to electronic ignition: the MGB required matching curves in the carb metering needles and vacuum-driven spark-advance in the points and my engine was parts-orphaned. But you can't blame Lucas for that).

Most owners are too slow to replace parts ("Gee, it looks okay") and trust too much in Lucas' cheerful optimism regarding using the vehicle as a ground return. I am convinced the "problem" with Lucas electrical systems is that they require a Simpson 260 (or AVOmeter) and an electronic tech's approach rather than a mechanic's; on my worst days, I think Lucas did the electrical systems on a nailboard, right to the vehicle-maker's spec, with nary a thought to what they'd be doing in a car. That's pretty alien to the way anyone who actually knows cars looks at 'em and it leads to troubleshooting problems.

C'mon, you can draw MGB electrical systems on a bar napkin without unfolding it; there's not that much there!

(Holy cow, I cannot find any how-to or illustrations of what a nailboard is. --It's a board. With finishing nails [or high-tech equiv.]in it, not hammered flush. Usually surfaced with a drawing of the wiring harness laid out flat, under plastic. It is still the standard way to build 'em, as the process is tricky-difficult to automate. Anyway, it's way easier to get at and work on than the installed end-product.)

Justthisguy said...

Is that also called a breadboard?

Roberta X said...

Not the same, no.

Roberta X said...

"Breadbaord" was originally a wooden chassis; inexpensive breadboards (cutting boards) or nice flat slabs that resembled them were the experimenter's best friend. Parts were made to mount on 'em and it was possible to do nice work. or just slap together a quick circuit. In the latter sense, they were used well into the metallic-chassis era and even non-wood-based rapid lash-ups came to be called by the name. When the nifty solderless prototyping boards showed up, the term was still around, hardly dusty, and was picked right up. (Wikipedia has more).

Where a "braedboad" usually has single blocks of, well, breadboard size while a nailboard can be huge; it's a flattened out, 1:1 scale map of a wiring harness that you build the harness right on. Or it can be 3-D. I wire up audio patch panels that way, on a little model of the rack or cabinet they well be installed in, as I don't like most of the prewired ones -- the makers have no idea how to do proper controlled shield grounding.