Gallery, Projects and General > How do I??
Math for machinist tapers...
NeoTech:
RusselT, yeah i have BT40 tool holder that i will use as a "key" to check the fit with. What im gonne cut is the inside cone for a spindle axle. I even considering lapping the final cone if i can get in there. And or have it plated and ground.. but i need to get the angle right before i try to do that. =)
This was very educational anyway.. These ratios for angles is not anything one learn in school anymore.. not me at least.
andyf:
--- Quote from: NeoTech on February 08, 2013, 03:29:35 PM ---This was very educational anyway.. These ratios for angles is not anything one learn in school anymore.. not me at least.
--- End quote ---
If Finland has the same road signs as most of Europe, Neotech, they use a similar system for gradients on hills. For example, "20%" means a gradient where you go 20 units up (or down) for each 100 units you travel horizontally, as viewed on a 2D map.
20:100 could be expressed as 1:5, and life was simpler here in the UK when the signs said things like "Steep Hill 1:5" which was pretty steep. When they said "1:3", things got very steep. Going up a long hill your engine coolant might boil. Worse still, your brake fluid might boil coming down, so you travelled rather fast near the bottom of the hill. Helpfully, the sign for a steep downward hill also said "Engage low gear now".
Andy
BillTodd:
--- Quote ---These ratios for angles is not anything one learn in school anymore.. not me at least.
--- End quote ---
You must have use Radians in school surely? :D
I suppose that as schools try to teach kids more and more 'stuff', the greater becomes the danger of missing out on the fundamentals .
I was amused by your description of defining an angle by 'Degrees' as modern :)
Chopping a circle up into an arbitrary* number of degrees is ancient and must be almost as old as describing an incline in terms of height and distance.
Bill
*360 degrees with 60 minutes and seconds was i'm sure chosen by our ancestors simply because 360 factors easily in a base 10 number system - a computer would be happier with a 256, 512 or any n^2 degree circle
NeoTech:
Well i was taught degress, not.. well angle ratios, or that 16min, 20s, thingy that people uses as well (that is another measurement i dont understand) ;D
BillTodd:
--- Quote ---(that is another measurement i dont understand)
--- End quote ---
You may be unfamiliar with it, but you can understand it! (because it is so simple) :)
1 degree = 60 minutes, .0.5° = 30 minutes, 0.25° = 15 minutes
1 minute = 60 seconds etc etc.
It's primary use is for quick, in-the-head*, maths for navigation. Powers of 60 factor (i.e. can be divided exactly) by 2,3,4,5,6 etc. making division by those factors easy and accurate.
eg. 25° 34' 18" divided by three = 8° 31' 29"
The same units are used on charts and navigating instruments so there's no need to convert.
In general, converting units should be avoided (or left to a computer ;)) as can easily lead to rounding or typographical errors, so if the standard says "inches per foot" stick with it
Bill
*fractions (e.g. of an inch) have some of the same 'magic' which is why they been around so long - It's only the wide spread use of calculating machines that makes metric/decimal systems attractive.
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