scale conversions

Or you could just say multiply the scale by two instead of all this confusing divide by 100 multiply by 200 malarky!

At last, someone who points out - albeit in rather a technical way - that A1 is NOT twice as big as A3, it's FOUR times as big. A1 is twice as big as A2, which is twice as big as A3, which is twice as big as A4 etc... So the scale from (say) 1:50 at A1 is not 1:100 at A3 but (I think) 1:200 at A3. It certainly makes sense on the plan I'm working on. My personal tip - measure a doorway - they are always around/just under one metre wide... that will give you your scale with any luck. Less mathematical, but more practical perhaps?

[JohnS]

Originally Posted by Unregistered

At last, someone who points out - albeit in rather a technical way - that A1 is NOT twice as big as A3, it's FOUR times as big. A1 is twice as big as A2, which is twice as big as A3, which is twice as big as A4 etc... So the scale from (say) 1:50 at A1 is not 1:100 at A3 but (I think) 1:200 at A3. It certainly makes sense on the plan I'm working on. My personal tip - measure a doorway - they are always around/just under one metre wide... that will give you your scale with any luck. Less mathematical, but more practical perhaps?

No the ratio between A1 and A3 is 1/4 the area or 1/2 the length and width. The correct scale is 1:100

One paper size is 2X on area and an inconvenient 1.414213X on length and width

I had a drawing which was to be printed on A0.The scale was 1:200 on A0. i accidently printed it on A3 sheets..I want to get the correct dimensions from the A3 drawings. is it possible??? I need ur help..

[JohnS]

Originally Posted by Unregistered

I had a drawing which was to be printed on A0.The scale was 1:200 on A0. i accidently printed it on A3 sheets..I want to get the correct dimensions from the A3 drawings. is it possible??? I need ur help..

The scale will be 1:200*2^(3/2) or 1:565.7 assuming the printer's magnification is precise. I would reprint either on the intended AO or A2 (1:400)

It's a nice idea, but it never actually works out correctly, especially if you print from PDFs... scale off the proper drawings!

[rbuake]

How do i calculate the radius of a curve from a known chord length?

[JohnS]

Originally Posted by rbuake

How do i calculate the radius of a curve from a known chord length?

It could be anything from half the chord length to infinity. You need to know the central angle as well. or the distance between the chord and arc measured at the center.

I need to convert 1:100 @ b1 my drawing is printed on A4 paper

any suggestions?

[JohnS]

Originally Posted by Unregistered

I need to convert 1:100 @ b1 my drawing is printed on A4 paper

any suggestions?

B1 paper has a length dimension of 1000 mm, A4, 297 mm.
Therefore 1 unit on the B1 drawing is shrunk to 0.297 units on the A4 print. Your scale is 0.297:100 or 1:336.7 which will be remarkably inconvenient to use.

You will not find a direct reading scale, so just measure with an ordinary ruler and multiply by 336.7