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morrisman
24th July 2012, 12:26 PM
A scan from an excellent book. WORKSHOP TECHNOLOGY by WAJ Chapman

In the two examples : If r = 2" then what would h be ?

grinding milling cutters

Last time I did trigenometry was 1971 , form 4

Mike

Chief Tiff
24th July 2012, 12:35 PM
You need to provide the angle "C" as well to solve this equation. You will also need either a scientific calculator or a copy of natural sine tables.

Example: If the clearance angle C is 10 degrees and cutter radius R is 2",

and H=R sinC,

then H = 2 X sin10 (0.17364)

= 0.34728" ( a bees wossname over 11/32")


You PC will have a calculator in the accessories file and they usually have a scientific one listed. I'm sure Google would produce copies of sine and tangent tables if you prefer those.

Pac man
24th July 2012, 12:37 PM
Have you looked in the back for the answer?:-

morrisman
24th July 2012, 12:47 PM
You need to provide the angle "C" as well to solve this equation.

yes your correct :doh:

OK make angle "C" five degrees

MIKE

Abratool
24th July 2012, 12:51 PM
A scan from an excellent book. WORKSHOP TECHNOLOGY by WAJ Chapman

In the two examples : If r = 2" then what would h be ?

grinding milling cutters

Last time I did trigenometry was 1971 , form 4

Mike
Mike
I can calculate accurately for you, but just took the short cut & looked up "Machinerys Handbook" 1957- 15th Edition page 1306
You do need to nominate the clearance angle required ....Lets take it at 5 degrees.
Then the offset distance for a 2 " radius wheel or a wheel of 4 " dia will be 0.174"
Hope this helps.
If you require the long hand method I can outline it, but you will need a set of Sine Tables.
The offset is not an extremely critical dimension as Milling cutters can have a clearance angle from a few degrees to say 10 degrees.
Hope this is of assistance.
regards
Bruce
ps A little while back I made a make do set up on my Surface Grinder using a Vee Block & stop to grind a Milling Slitter saw. All went well.

BobL
24th July 2012, 12:53 PM
yes your correct :doh:

OK make angle "C" five degrees

MIKE

if C = 5º and R = 2" then h = 2 x sin(5º) = 2 x 0.087 = 0.174" = 4.4 mm

morrisman
24th July 2012, 06:52 PM
Ok got it :2tsup:

barkersegg
24th July 2012, 06:55 PM
Mike,

If you are using Microsoft then they have a very good freebie program called Microsoft Mathematics which covers trig functions and heaps more ....essentially means you don't need log tables, slide rules or those new fangled calculator thingies that come with a 300 page instruction manual the size of a postage stamp....:no:

It's far better than the standard one which comes with Windows and you can download it here Download: Microsoft Mathematics 4.0 - Microsoft Download Center - Download Details (http://www.microsoft.com/en-us/download/details.aspx?id=15702)

Hope that helps.....................Lee

Gerbilsquasher
25th July 2012, 08:03 PM
A scan from an excellent book. WORKSHOP TECHNOLOGY by WAJ Chapman

+1

Other the years I have hunted down all three volumes but it was when I read volume 1 at high school and gazed longingly at the Colchester lathe little did I realise that it would take 20 years to get one in my shed.

If engineering is religion then this is definitely a holy text, and a blast from the past that any youngster would profit by reading.... if they could be bothered.:D

One trick I use if you have access to CAD is you can always draw up the angles involved and measure it to check your calculations, always good if you don't use trig on a daily basis and get the opposite instead of the adjacent on the hypotenuse or vice versa.:oo:

morrisman
25th July 2012, 09:06 PM
Hi Gerbel

I picked up a copy of part 1 today ( vol 1 ) , it's as good as part 2 .Both of mine are 1972 editions

He seems to like maths , I see he has written a book:

Elementary workshop calculations and also Senior workshop calculations

I'm looking for part 3 :2tsup: Mike