What Did You Buy Today?

[BGHansen]

Not sure if you have a smart phone Bruce but there are numerous apps that you can download to emulate scientific calculators. I use CalcTastic on mine to emulate a TI-84. Works very well. I do get having a stand alone calculator though.

Actually my favorite is an HP-67 programmable calculator, have that app on my phone. I seem to fat-finger more often on the touch screen plus grime up the display. Just prefer the tactile feedback of a "real" calculator. My next purchase will be a full-size IP-65 keyboard for the Tormach. I despise my current mini keyboard.

Bruce

 

[Bi11Hudson]

My thinking here is that "Trig" functions use a look-up table. That alone takes up a LOT of memory. Most phone apps use an approximation that is calculated. And many "scientific" calculators and some computers. For any real tight figuring, I use the trig tables from a print book, usually Machinery's Handbook or some such.

I don't trust "electronic devices" much more than doing rough figuring in my head. 50+ years of working rotating magnetics has left a large number of "approximations" in my memory. Of specific note is Sin 30* is one half and Cos 30* is 0.866. Sin (and Cos) 45* is 0.7471. Memory there predates electronic devices. That gives a number of further approximations simply from juggling the numbers.

The whole point I'm trying to make is if you need trig, learn trig. As machinists, we don't need any more than plane trig, right triangle solution. The solutions can be learned in about 30 minutes. . . Well, call it an hour. I've taught it in 20 minutes and it took another 20 minutes to memorize the functions. If I had attended high school, it may have taken a day, no more. But I'm a grammar school dropout. . .

Whatever you do, don't depend on some external device. Learn and use something in your head for doing rough figuring. And a "lookup table" for closer figuring. The electronic devices make things go faster but you must know roughly what you're looking for before you start.

Sermon finished. . .

.

 

[Zyox Jägergeist]

I program cnc stuff by long hand, having two calculators is pretty much needed, the phones run out of battery or dim the screen witch gets real annoying, after 7 hours of programming phone batteries just don’t last.

 

[Ianagos]

I did give glacern a call and they did admit to copying the parlec vise but I couldn’t get a strait answer on if they were made in the same factory as the teco/parlec. From what I gathered the more premium options are cast by a Japanese company (only was told the company was Japanese not where they are cast) and ground in the USA. So I didn’t really make a conclusion because some of my questions got diverted in such a way to as to avoid being answered. But the fellow I spoke to was very nice and I had no issues with customer service.

The way I see it he was a good salesman he left me more confused and pushed me to the higher quality products that he assured me were made here while we didn’t talk much about the standard options as he called it.

 

[extropic]

Bill,
I don't expect your "sermon" will yield many converts to using trig tables, but I agree that having an internal (automatic and always running in the background) understanding of the fundamentals is important.

The most ridiculous example I can think of is the cashier that miss-keys the amount tendered ($200 instead of $20) and can't make correct change (has to cancel the transaction and start over) out of his/her head.

 

[NCjeeper]

I‘ve bought working, street legal, licensable and drivable cars for less than that vise.

Me too. Paid 75 bucks for a 1968 chevy 2 door. 307 v8 and 3 on the tree. That was back in 1984 though. Drove it for 2 years until the motor dropped a valve. Sold it to a junkyard for 50 bucks.

 

[NCjeeper]

Not metal related but I did use power tools to mount them. New houses for the locals.

 

[BGHansen]

Bill,
I don't expect your "sermon" will yield many converts to using trig tables, but I agree that having an internal (automatic and always running in the background) understanding of the fundamentals is important.

The most ridiculous example I can think of is the cashier that miss-keys the amount tendered ($200 instead of $20) and can't make correct change (has to cancel the transaction and start over) out of his/her head.

+1. I learned trig in junior high, high school and college classes, haven't used a trig table since high school. So much more convenient to have a side opposite of 15 and an adjacent of 23.5 in a right angle triangle and use the calculator to get the tangent of the angle being 0.638297872. Hit Shift TAN which tells me it's a 32.55000349 degree angle. I learned long division in probably 3rd grade along with times tables. I think I could still divide 15 by 23.5 using long division, but it's so much faster using the tech.

Naturally, you have to understand the background to work the problem and get the right answer. My sister taught high school math which now requires a calculator. She'd put problems on a test with a right angle triangle and maybe gave them the angles and the length of the hypotenuse. If she asked for the length of the side adjacent, one of the multiple choice answers would be the sine of the angle times the hypotenuse (should be cosine times hypotenuse) to test if they understood the relationships.

Bruce

 

[hman]

Bi11Hudson - I "grew up" in the sliderule era. One very valuable "lesson" in that method is the requirement to do an approximate/rough calculation in your head, so that you could keep track of the decimal place. Also valuable in that a nonsensical answer stands out if it's way different than your guesstimate, and you have a chance to correct your error.

Just punching keys on a calculator and trusting what comes up on the display can lead to disaster. Kinda relates to the point that @extropic made about cashiers. Been there, seen that, sometimes even had a good laugh.

PS to Bill - The calculation methods used for trig, log, etc. functions on a calculator are tried, tested, and accurate to the number of decimal places the calculator can work with/display. This can be verified, both against published tables and with self-consistency tests. In any case, at least as good as the 5 or so digits you'll find in tables. So if you ever do find yourself needing to use a calculator, you don't have to be concerned with the accuracy of the results. But use what you're used to working with!

... not that any of us machinists are likely to need more than 5 place accuracy.

 

[DLF]

Got a beautiful set of SOMET gage blocks: 1.001 ... 1.009mm. New old stock, in mint condition

A gage block accessory set. Again new old stock in good condition (still has the ear wax on all the parts), but the wooden box has a lot of patina (has seen better days, but not broken or something).

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