SCALE CALCULATOR. How To Up And Down Scale Models.

[dansls1]

Originally Posted by Stev0

Ummm???? Just divide the scale you want into the scale it is currently at. For the percentage you multiply that number by 100.

Ex. 1/48 scale is the current model size ... you want 1/25 scale. You divide 48/25=1.92 or 192% Enlargement.

Ex. 1/33 scale is the current model size ... you want 1/72 scale. You divide 33/72=0.458333~ or 45.8333% Reduction.

The key is to NOT round down. Keep decimals.

I use this method in Autocad on a daily basis.

A/B=C*100=PrintSize% <= For Equation Fanatics

The thing that caught my eye was the handy train scale reference...

[SCEtoAUX]

Originally Posted by Stev0

Ummm???? Just divide the scale you want into the scale it is currently at. For the percentage you multiply that number by 100.

Ex. 1/48 scale is the current model size ... you want 1/25 scale. You divide 48/25=1.92 or 192% Enlargement.

Ex. 1/33 scale is the current model size ... you want 1/72 scale. You divide 33/72=0.458333~ or 45.8333% Reduction.

The key is to NOT round down. Keep decimals.

I use this method in Autocad on a daily basis.

A/B=C*100=PrintSize% <= For Equation Fanatics

A long time ago, must have been in the early 1960's, I read a scifi story about a guy that could do math problems using pen and paper instead of using a calculator. The government people were astounded that someone could actually do something like that and hatched a plan to put him in the nose cone of a missle so he could guide it to take out the enemy. At least that is how I remember it. Could have the plot and details all screwed up, but the general gist of the story is close. I think that Isaac Asimov was the author (could be wrong about that, too).
So, Stev0, got any plans for the near future? :p :D

[RyanShort]

Originally Posted by Stev0

Ummm???? Just divide the scale you want into the scale it is currently at. For the percentage you multiply that number by 100.

Ex. 1/48 scale is the current model size ... you want 1/25 scale. You divide 48/25=1.92 or 192% Enlargement.

Ex. 1/33 scale is the current model size ... you want 1/72 scale. You divide 33/72=0.458333~ or 45.8333% Reduction.

The key is to NOT round down. Keep decimals.

I use this method in Autocad on a daily basis.

A/B=C*100=PrintSize% <= For Equation Fanatics

Exactly! It is SO NOT rocket science! I've been doing this for years...
We've gone through this on another forum before... Always amazes me how hard it is for some good folks to do the math.

Ryan

[ringmaster]

Now, if designer would just print the scale on their models.....

[redhorse]

Yes! I agree with ringmaster. That would be very handy sometimes!

[whulsey]

Aye, that is the rub (apologies to Shakespere and Hamlet) knowing what the original scale is.

[birder]

there needs to be some frame of reference. You may just have to measure the fuse or wing and look up what the real one was, and adjust from there.

[pahorace]

I believe that every designer who respects, it should draw the ruler graduated on sheets [rarely exists! But it is important!].

With regard to scale, I personally prefer (for aircrafts) 1 / 48 (I say to Ryan that already twice invited me to re-scale, in other discussions) because the scale 1 / 72, I believe (and perhaps wrongly) too small to contain sufficient details, especially of the Interior.
For this I prefer re-scale downward and not upward.

Orazio.

[dansls1]

Originally Posted by Stev0

Ummm???? Just divide the scale you want into the scale it is currently at. For the percentage you multiply that number by 100.

Ex. 1/48 scale is the current model size ... you want 1/25 scale. You divide 48/25=1.92 or 192% Enlargement.

Ex. 1/33 scale is the current model size ... you want 1/72 scale. You divide 33/72=0.458333~ or 45.8333% Reduction.

The key is to NOT round down. Keep decimals.

I use this method in Autocad on a daily basis.

A/B=C*100=PrintSize% <= For Equation Fanatics

Heh - I was going through the train scales here and realized there's an error in how this is stated. It's not a 45.8333% reduction, it's 'reduce to 45.8333% of the original size'.

[Golden Bear]

Maybe this will take the thread the wrong direction (i.e. apologies if it does). For my design work I need to know how to translate things from dpi to scale and to real life.

For a start, at 600 dpi:
1mm = (600 dots/in)/(25.4mm/in) = 23.62 dots/mm
Card is ~.4mm = 9.45 dots
paper is ~.2mm = 4.72 dots
card + paper is ~.6mm = 14.17 dots
card + card + paper is ~ 1mm, therefore 23.62 dots

For scaling from full size (600 dpi used as example):
1 actual foot = 600 dots/in times 12 in/foot = 7200 dots (3600 at 1/300, etc.)
At scale, 7200/(scale)... for 1:250, 7200/250 + 28.8 dots/foot
Going the other way, 1 dot at scale is (scale)/600dpi or 250/600 =0.42 inches

I used this last to calculate deck plank width on a recent model. I have a photo where I counted the number of planks across the width. Then I measured the number of dots in the scaled drawing for the same width, did the division and found 5.8498 dots per plank. Multiply by 0.41667 and the width was 2.427 inches - matching nearly perfectly the .jpg of planking that I use.

So much for my own esoterica...


Carl