Shop Math = Trigonometry or Bust

[Janderso]

I'm no math wizard but I am determined to relearn trigonometry.

I have found recently I need to prove/confirm my set-ups for milling and surface grinding.
I am looking for a compound sine plate and if I ever find one within my budget I plan on using it.

I stumbled upon Ray Galant's, Youtube channel. His handle is, Shop Math.

He has really helped me understand a few very important concepts.

 

[higgite]

Ray's not bad at math, but his spelling could use a little work.

Tom

 

[Lo-Fi]

Khan Academy videos are excellent too if you want it covered from another angle (pun intended)

 

[DavidR8]

Also NancyPi

 

[Janderso]

Hadn't been exposed to either of those sites, thanks.

 

[benmychree]

I was a poor math student in school, even with tutoring; algebra made no sense to me, but trig was easier because you could see the physical shape of things, if I can find the formula in machinery's handbook without having to rehash it (algebra deficiency) I could work out a problem. My use of it is mostly confined to figuring approximate leads of spirals for the milling machine in cutting mostly spiral gears, I try to determine the spiral angle of the sample gear and from that come up with an approximate lead of spiral, consult the B&S book with a table of spiral leads, set up a gear train and with the sample gear in place on the dividing head, use a DTI to detect whether the spiral is too fast or slow, and set up other gear trains until I get it right on, usually this may take only several tries. The spiral angle is measured on the pitch diameter, something that is not really easy.

 

[4ssss]

Why bother. I learned Trig in Trade School and haven't used it since. That's why Engineers' make the big money.

 

[Janderso]

Sounds very complicated.
My favorite math problems were in geometry for the same reason, you can see the problem and work it out.

 

[Janderso]

Why bother. I learned Trig in Trade School and haven't used it since. That's why Engineers' make the big money.

It's one of those things that is lost if you don't use it. Speaking for myself of course.

 

[Lo-Fi]

Khan Academy got me through some pretty heavy vector maths when writing a game expansion (Google my forum name and Kerbal Foundries if curious). 3Blue1Brown if you're in the mood for advanced Calculus.

That all being said, I don't do trig manually myself any more. If I need to work something out, I draw it up in a 2D cad sketch and get the computer to do the heavy lifting for me. It's literally impossible to get the wrong formula or have a brain fart with the calculator. I can even do this on the Onshape phone app!

Its funny: "you don't always have a calculator with you" was a phrase often thrown around to encourage manual calculation when I was in school...

Hold. My. Beer.

Brushing up on an overview of trig it is great, but further than that, time could be better spent learning a cad package. In my humble opinion.

I use CAD literally all the time in my shop. Not that I draw everything up in 3D - often it's simple 2D stuff like hole patterns. Great example is T nuts: I wanted to knock four out of a single piece of stock. I could have manually calculated the hole spacing, giving allowance for saw cuts, cleanup etc.... It took me literally a minute to knock up a 2D drawing, which then allowed me to show dimensions from any datum. I defy anyone to do it quicker with pen and paper. More like using it as a truly graphical calculator in this context, and it works just as well for stuff you'd ordinarily need trig for: Draw your triangle. Dimension the bits you know. Click to display the dimensions you don't know and the solver does the heavy stuff in a nanosecond. Need to change it? Modify any dimension and everything else is automatically recalculated. Food for thought, anyway