Drilling a compound hole

[shopandmath]

Drilling a compound hole
This video covers the math and setup concepts
Of how to drill compound hole using only 2 angle
And no length dimensions
Video link

[mklotz]

FYI, unsurprisingly, there is an online calculator to solve compound sine plate setups, including computation of stack sizes

https://www.subtool.com/st/how_to_se...ine_plate.html

I admire your effort to teach the mathematics involved but I fear, given the state of math education today, that most of your students would bog down trying to do it on their own. Specialized calculators like the above are gradually removing that problem and, of course, worsening the state of math education.

One comment from my own teaching experience. Referring to the "inverse tangent" (or inverse sine/cosine) is often erroneously interpreted by the student as 1/tangent since he learned that 1/x is the inverse of "x". It's better to refer to the "arctangent" and explain that the arctangent of x is the angle whose tangent is x.

While many calculators have the arctangent marked as tan^-1, the better ones like HP have it marked as atan. I suspect that's due to the possible confusion to which I alluded.

[Frank S]

Having lost much of my skills in math over the years form disuse and as Marv stated the advent and ready access of calculators both online and slide or rotary card types I never tire reading these explanatory and informative threads.

[shopandmath]

Hi mklotz
I tried to use the link you supplied and it does not do calculations for holes
Or I can not get it to work for me
I have also tried the program from web machinist with out luck
This is video 4 of 4 in a series on compound holes I am working back to front
I need the other 3 done by next Thursday
The biggest problem is the voice overs (I even spelt my name wrong on the cover page)
Thank you for your comments and input
Ray

[shopandmath]

Hi Frank S
Thank You for commenting
Its encouraging
Every I see a slide ruler - slide chart at a grange sale or swap meet
For cheep I pick them up half or them I do not know how to use them :-)
Ray