Radius/ Angle/ Maths Question

[craigthewelder]

Does anyone know of a formula for working out dimensions A and B on the attached drawing. As we don't use CAD at our works i can't just put it into the computer to get the dimensions!

Center line radius is 2500mm, angle is 70° and the chord length is 2867.9mm, i just can't find anything to help me work out the height and length. I know there are some clever people on here so any help is gratefully appreciated.

 

[Maker]

The angle between B and 2867.9 is 35*

2867.9*cos(35) = B = 2349.25

A = sqrt(2867.9^2 - 2349.25^2) = 1644.96

 

[rtbcomp]

The bottom left acute angle is 35 deg, the hypotenuse is 2867.9 so use COS and SIN tables to calculate A & B

Cos35 = B/2867.9, Sin35 = A/2867.9

EDIT - Pipped at the post!

 

[malcolm]

I was too slow too, but it's fun to have a Wednesday morning maths puzzle. Did a picture of another way of working it out. The slightly different answer from Maker is because the value for the chord has already been rounded.

 

[rtbcomp]

More slightly different answers because I've scaled & re-scaled the drawing so the dimensions are legible!

 

[Maker]

It is nice to see hand drawings are still used in some places.

 

[craigthewelder]

Yes we are still stuck in the dark ages as far as drawings are concerned. Though some of our customers that have the all singing Cad packages still manage to produce terrible drawings, they have a habit of giving you all the dimensions you don't need and none of the ones that matter!

Thank you for the replies, they have been of a great help. You are all gentlemen and scholars.

 

[rtbcomp]

I got really frustrated with technical drawing at school - I really admired engineering drawings, especially those of sectioned cars in workshop manuals but I couldn't draw a straight line with a ruler!

 

[ajlelectronics]

I couldn't draw a straight line with a ruler!

It's always a problem trying to get Her Maj. To help too!

 

[roofman]

just bend a welding rod till it looks right....all the clever ones above take notice

 

[J.B. Welding]

I love online calculators!!

Cleave Books do some awesome calcs, and there are others and all free and easy to work with.

http://www.cleavebooks.co.uk/scol/calsect.htm

Index http://www.cleavebooks.co.uk/scol/index.htm

 

[graffian]

It's something everyone who makes stuff should know!