On 4/12/24 11:30, Chris Albertson wrote:
All very true and well for someone equipt with the income and mental gear to use that chain of tools
profitably. But I'm an old Iowa farm kid, we made what we needed. The "store" was 15 miles
of horse drawn wagon over a mud road the county graded about 2x a year and all of a days ride in a
wagon away. So we grew it, or made it from the woodyard, whatever. 2 miles to the 1 room school, I rode
an old gentle mare the first mile but had to walk the 2nd mile because there wasn't a barn for the mare
during the day any closer to the school when the weather was bad. Grandpa across the road had
electricity, a 32 volt delco wet glass batteries, charged by a zenith windcharger. The prop broke, so
mother who was the only girl in the 1929 class on aviation technology at Des Moines Tech Hi School,
proceeded to teach her father how to carve the wing chord in a new prop. Worked well in less wind than
the one we could get from Chicago. That led to grandpa having the first electric washing machine in
Madison County Ia when the Maytag hit & miss tried to start backwards, broke the starter gears and
grandma's ankle. A wagon load of shelled corn went to town, and was replaced by an electric motor and
enough heavy wire to convert the Maytag. I still wear scars on one hand from getting it caught in the
wringer when I was 5. We did not want for anything, we "made do" That is a hard habit to
outgrow.
But today you own a computer, lots of CNC equipment, a 3D printer and education
is free and just a mouse click away. None of the stuff I wrote about costs
even one dollar. I’m the old ririred guy now. Fusion360 is free to use. I
can print ther prats and then if. Needed sand the same design to CNC machine or
to an injection molder
I think you are right about relativity, Einstein very much admired James Clerk
Maxwell. Someone said Einstein ”stood on the shoulders of Newton”. Einstein
corrected him and said “I stood on Maxwell’s shoulders”.
Thanks for the story. I always like to hear those “when I was a kid…”
stories. My four grandparents were born in 1902 through 1911 they could talk
about the days before radio broadcasting and one-room schoolhouses. One
grandfather was a professional boxer in the 1920s and traveled a lot. But
even more interesting to me, my wife’s parents and uncles were born in pre-war
Japan. I think they lived through more change than any living American.
Sadly the last of them is in very poor health. My wife is visting her mom in
Tokyo right now.
Many thanks for the flowers Chris, and while I wish a long
non-alsheimers life for the MIL, I can testify that time is a one way
arrow and relentless.
As I rebuild the ender5+, (I'm also redoing a tronxy-400) one of the
things it never did was syncing the two z screws, apparently creality
figured the many point bed mesh was enough so it just paralleled two
small motors. So I just swapped one Z motor for a longer one I'd removed
from another printer, unplugged the other so its just a bearing, put two
20 tooth pulleys on the screws, installed a belt about 15 teeth longer
than needed, and am now printing the first half of a belt tensioner so I
can slightly adjust the timing of the two screws to cancel bed tilt.
QIDI does that on the xmax3, works great. Set and forget, no electronics
involved.
I should knock john D's problem up in openscad, might yet if he ever
gives us the whole spec so I know what he's trying to do. To me it only
needs 3 axis's as long as one is rotary. Those fast A & B's I have built
have been handier than sliced bread. Speeds up to around 500 rpm, plenty
accurate enough for what we do. Chucks on them are printed to do one
job, hold a square stick of hard maple on center.
I didn't have what it takes to do the math to get the 7 degree load face
of a buttress thread, so I just put a printed wedge under the spindle
motor. Solves all that math bs in one swell foop. When all you have is a
hammer, lots of stuff looks like a nail. ;o)> I think that problem will
boil down to maybe three master vars, one for the X stepped by whatever
make a good DOC, X and A then derived from that by trig scaling, and
probably Z for the venturi curve also needed, all from the single master
var being stepped. A second var manages the angles of the pie slice of
material being removed and a 3rd determines the angular origin of that
slice, all the rest of is done by lcnc's trig stuff. I think, given
enough time, I could make it work in straight gcode probably using
polar/rectangular syntax for some of it. Lcnc is often my hammer.
Historically I've been very good at visualizing how mechanical things
worked. At 19 I was working in a hifi store, and record changers that
weren't were all put on my bench where I straitened bent parts and made
them work again. Had 4 or 5 other EE (this was Iowa City, whose EE
school was one of the best) students who taught me a lot about
electronics, but I was also constantly amazed at how poorly their hands
actually fit the tools we used in the 50's. I was driving a 49 Nash
Ambassador at the time that I'd played with a bit, got 20+ mpg at 120
mph. It took a Duntov Chevy's 270 hp to outrun me.
I asked a friend of mine what happened, he's a bit of a philosophy
major, said 'inside every old man is a kid wondering what the @#$%&
happened." He was right, as usual.
[...]
Cheers, Gene Heskett, CET.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
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