Oh Shoot!

[Jim Koepke]

It seems like the tweezers and toaster tongs are a success at the farmers market so more need to be made.

Especially the toaster tongs since no pictures were taken. They are like the tweezers only with no tips, just flat ends slightly rounded.

To speed things up a way to quickly cut a smooth angle at the top was needed. I knew a shooting board would be the right thing but how?

While thinking of the various ways to make a sliding holder this came to mind:

290226

A quick trig calculation was done to figure out the angle, ~3º, and then a piece of scrap was cut and smoothed.

It holds the work piece while keeping my fingers away from the blade.

jtk

[Bill Houghton]

Clever. Your - and my - math teachers were right about how useful math is.

[Jim Koepke]

Clever. Your - and my - math teachers were right about how useful math is.

There is a trig table and a slide rule in the shop, no calculator. I am not proficient with a slide rule don't really use it much.

jtk

[Winton Applegate]

I must not be seeing it right.
Ha, ha.
It looks like you are going to take the skin off the back of your thumb any second.


Slide rule.
I have a quick story :
I used to see my Dad bring home plans (he was a big time pipe fitter; steel mills, dam flood gates I don't know what all). Well big time to me. He had wrenches in his truck longer than I was.
He was always using his slide rule.

When I went to "the big kids school" middle school, I was alllllll set to learn some thing useful.
So . . . one day in math class after a long school year, the teacher said "class . . . since we are coming to the end of the year I thought I might leave it up to you what we study next. What do you want to learn ? Does any body have any suggestions ?"

My hand shot up and I said "I want to learn how to use a slide rule".

Well . . . . . . . . .
. . . . . . . . .
so began my long and infamous tradition of making comments in class that had the effect of leaving the room so quiet one could hear the proverbial pin drop and without fail accompanied by the teacher's look that often said something along the lines of "I wonder if that job in Alaska on the salmon fishing boat is still open".

[Jim Koepke]

When I started secondary school, grade 7-12 all at the same school, slide rules were still in use. By the time it came for me to graduate calculators were in fashion. By my 30th year, most people younger than me would look at you funny if you said "slip stick" or "slide rule."

I recall a blurb in the SF paper about a book store near UCB clearing out what was left of their old slide rules. There were mostly people older than me pawing through the dismal pickings. I got a nice off brand model with a nice leather case. I think if I looked hard around here I could find three or four packed away. There is one my father gave me and another from a yard sale out in the shop.

They still come in handy and they still need no batteries.

jtk

[Jim Koepke]

It looks like you are going to take the skin off the back of your thumb any second.

The part being cut is only about 2". My thumb is back about 8" and there is a good space between it and the sole of the plane.

It just looks close because of the camera angle. It wasn't possible to move the camera more to the right without moving a lot more stuff.

jtk

[Jason Roehl]

My "slide rule" is an HP 42S RPN calculator. I bet you would be hard pressed to find anyone under 40 who even knows what RPN is. I think I paid about $175 or so for that calculator in 1990 or so. I still have it, and it still works great. EXCEPT that I now have a free 42S emulator app for my iPhone, so the 42S sits unused in the desk drawer.

I've never used a slide rule, though I suspect if I sat down with one I could have it figured out after a spell.

[Jim Koepke]

RPN

We used to call that Reverse Polar Notation. (Polar is more politically correct than what it was usually referred to in place of the P.)

jtk

[Robert McNaull]

Since this has already gone off subject, I use math every day, work especially. Burried in data and statistics just about every day, a nice little software package called Matlab however is what does the heavy lifting. My wife is a high school math teacher, teaches pre-algebra and geometry. She gets really frustrated with kids sometimes, they can't hardly add 2 numbers without a calculator anymore. Calculators.... ugh, makes us dumber in some ways, my last college math class I took a couple years ago used no calculators, had to do a bunch of matrix math by hand.

Back to subject, like the jig or guide, a shooting board is on my list of needed projects on a long list of wants.

[Jim Koepke]

a shooting board is on my list of needed projects on a long list of wants.

They are easy to make. My next one will have less thickness to the platform. That will allow more of the plane's blade to be used.

jtk

[Rob Lee]

My "slide rule" is an HP 42S RPN calculator. I bet you would be hard pressed to find anyone under 40 who even knows what RPN is. I think I paid about $175 or so for that calculator in 1990 or so. I still have it, and it still works great. EXCEPT that I now have a free 42S emulator app for my iPhone, so the 42S sits unused in the desk drawer.

I've never used a slide rule, though I suspect if I sat down with one I could have it figured out after a spell.

Ha...HP 41CV for me.... Still have it in my shop. Bought it at the same time as my Casio watch, which apparently means I'm a " hipster" now....

:)

Cheers,

Rob

[Jim Ritter]

I miss my HP 41. It died years ago, damn salt air.
Jim

[John Stankus]

...My wife is a high school math teacher, teaches pre-algebra and geometry. She gets really frustrated with kids sometimes, they can't hardly add 2 numbers without a calculator anymore. Calculators.... ugh, makes us dumber in some ways, my last college math class I took a couple years ago used no calculators, had to do a bunch of matrix math by hand.



My personal observation teaching College Chemistry is that calculators have reduced students' "number sense". I have had students faced with a problem that is essentially some number multiplied by one (sometimes even by zero) reach for their calculator. Usually at that time, in my best Dragnet bullhorn voice, I tell them "Step away from the calculator". Don't get me started on students' difficulties with fractions.

I came up through school just as calculators were starting to become affordable. They were not common, so I got into the habit of doing as much calculation by algebraic simplification before either doing the math longhand or borrowing a calculator. I think that gave me a much better sense of the math.

I usually have a slide rule in my briefcase for the first exam, which I offer to students who forget their calculator (then I pull out one of my spares).

Also, RPN actually stands for Reverse Polish Notation, which is called such since a Polish mathematician developed the notation (or rather the forward version). It probably should have been called reverse Lukasiewicz notation.

John

[Stew Hagerty]

I went to HS in the 70's (graduated in '77) which was exactly on the Slide Rule/Calculator boundary. We learned how to use a slide rule, but also had calculators. In fact, in both physics and Chemistry classes, we were allowed to use slide rules on tests whereas calculators were forbidden. My first calculator was a Casio fx-10 (see below). The fx-10, which came out in 1974, was Casio's first "scientific calculator". I don't remember the exact amount, my parents paid for it, but I know it was fairly expensive at the time.

My how things have changed...

I went to school at Tri-State University (Angola, IN) which, at least at the time, was one of the top engineering schools in the US. Even there, calculators and slide rules battled for supremacy.

It's funny, at that time Tri-State had just one single computer on campus. We studied Fortran & Cobol machine languages and wrote programs on key-punch cards.

I had a physics teacher that told a story about his time in college. He was going to have a test the next day and the students were all asking questions about it. One student asked what all they were allowed to use during the testing. The teacher stated that it would be an open book test, and that nothing was banned. The student followed up by asking: "So we can use slide rules and log tables. Tired of the questions, the teacher said "This test will be very difficult. I don't care what you use. If you can carry it through the door, you can use it." The next day rolls around and the students are coming in carrying their slide rules, books, tables, etc. Then one student, who happened to be one of Linebackers for their football team, strolled into the room carrying an engineering Grad Student.

The teacher asked (over the roar of laughter) what the heck was going on. The student said "You said we could use anything we could carry through the door."

The teacher shook his head then started laughing too.

The student aced the test.


http://www.johnwolff.id.au/calculators/Casio/CasioFX10-1388-IMG_5753-5.jpg

[Jim Koepke]

My personal observation teaching College Chemistry is that calculators have reduced students' "number sense".

My personal experience supports this observation. Multiplying 3 digit numbers by other 3 digit numbers is not a difficulty for me. After using a calculator for a while I noticed my mental math proficiency was diminishing. That is when I put calculators aside and went back to thinking through the answers to math problems.

For some things I still use a calculator. Mostly at the farmers market to figure out what the breakdown of sales tax on an item sold without the customer being charged tax. Division was never a strong point of mine.

Some customers complain about having to pay taxes. So most of the time I just set the price to include the tax then back it out later.

jtk