Making circles

[tracywiedrich]

I dunno if'n this is really tech or not but its sumthing I learned years ago when I was a insulator and I still use it in the shop quite often. When trying to use a divider for laying out circles it can be hard to figure out what half of a certain fraction is. For example half of 2.1/4 is 1.1/8 right? well thats easy, but how about half of like 13.1/4? Not quite so easy to do in yur head right? Well the method I use makes  it a lot simplier ...here goes... first you know that half of 13 cant be 7, so it has to be 6 right? That the first part...now for the fraction part, well you know that half of a 1/4 is a eighth  right? Well the bottom of your  fraction is a eight then... so now you have 6.0/8, now all you have left to do is to find the top of your fraction. And for that all you have to do is add the top and bottom parts of your fraction...1+4=5...so half of 13.1/4 is 6.5/8.. hows that for confusion?

[Eyeball]

Ok I follow that one. I have alway had trouble with fractions so I usuall use a chart I have in the garage that converts them to decimal and then use a calculator and then back to the chart again.

Will it work for exaple on 4 5/16?

[tracywiedrich]

Eyeball, I should have mentioned that its really for uneven numbers, cause half of 4.5/16 would just be half a 4=2 and half of 5/16 which would be 5/32nds=2.5/16, those you can figure out cause half of a even number fraction is always just half of the fraction...clear as mud huh? for example half of 3/4 is 3/8, 5/8 is 5/16 etc but its when you have a uneven whole number where this method shines...

[Eyeball]

OK I got cha......fractions........hate em. Once I started building cars I realized that I should have paid more attention in math and geometry class..........still have not needed history though, and thank god for spell check! (when I remember to use it)

[tracywiedrich]

Hey man dont feel bad, I am the worlds worst mathematician. The only reason I learned this is besause I could see a real world reason for using it. The old guy that  taught me that was married to a math teacher and he saw me scratching my head one day. If I can use it in the shop I'll try to learn but if I can't ,I figure I cant spare the space in my head...hahaha ...speaking of spellcheck you might have noticed I had to edit this cause I had so many words screwed up

[ratfink]

You guys might already know this but here goes anyway.......A easy way to remember AN hose and fitting sizes is to use the "16th rule" For example: -8=8/16 or 1/2 and -6=6/16 or 3/8 and so on.......

[sko_ford]

charts, did some one say charts

[Eyeball]

nice I will print them out tomorrow at work.