Outside the box

[garyd]

The calculator that is...

This is a problem I deal with successfully on a periodic basis on the job.

Just for you peeps I will keep it as simple as possible without making it rediculous.

Your calculator has just died. You've got a cylindrical part 1/2 an inch thick (12.7 mm if you just have to have metric). You've got to drill 3 holes though it, from top to bottom. The holes are 1/4 inch (roughly 6.35 mm if you just have to complicate your life) in diameter and laid out equally spaced on a 3 inch (76.2mm) circle. The machine you are using has an attachment that gives you an x,y coordinate system. It does not do calculation involving division by numbers other than 2 or any other calculations at all. After securing the part in the vise mounted on the machine and finding the center point of the top surface which we shall now call 0,0 give me the coordinate locations of the three holes you need to drill. Or at least tell me how you'd go about finding said coordinates. Remember no calculators oh and you don't have any trig tables either. YOur hole location tolerance is plus or minus .01.

 

[hjmick]

You using a CNC machine? Never mind. You're using a mill with the requisite X/Y coordinate display.

 

[garyd]

Nope I'm using a Bridge port mill with a digital readout, an old and nearly useless digital read out at best.

 

[hjmick]

I hear ya. Those things can be twitchy.

 

[garyd]

So how would you do it?

 

[hjmick]

So how would you do it?

I would use AutoCAD. LOL.

I've been thinking about it, but word problems are not my strong suit. Give me a blueprint and a CNC machine and I could get it done. I haven't touched a Bridgeport in over a decade. It's funny what you forget when you no longer use it.

 

[garyd]

I've been doing CNC and manual for most of the last 30 years. Part of the problem is that if you graduated high school in the last ten years you weren't required to memorise even basic math facts. For instance how many people today can tell you the sine of 30 degrees of the top of their heads or that the tangent of 45 degrees. I had those things drummed into me when I took trig back in the sixties. And then theirs that old greek every body ignores.