Scaling

[ronwalker]

Hi
When rescaling from one to another ie 1-100 to 1-300 or 1-72 to 1-150 how do you calculate them. Does anyone have a chart or easy to understand formula. I mainly use photoshop to upscale from 1-300 but usually just scale the plan to fit A4. I think I'd now like to be more specific with proper scales. Could anyone help?
Regards Ron

[SCEtoAUX]

Take the scale you have and divide by the scale you want then multiply the result by 100 to get the percent you print the original at to get the scale you want.

1:100 to 1:300
100/300 = .3333
.3333 x 100 = 33.33%. So you would print the 1:100 scale pages at 33.33% to get a 1:300 scale model.

1:72 to 1:150
72/150 = .48
.48 x 100 = 48% So you would print the 1:72 scale pages at 48% to get a 1:150 scale model.

1:48 to 1:32
48/32 = 1.50
1.50 x 100 = 150% so you would print the 1:48 scale pages at 150% to get a 1/32 scale model.

Remember that when you are increasing the size you will have to make sure the parts fit on the size paper or cardstock that you have.

[ronwalker]

Hi SCEtoAUX
Thanks so much for the very speed reply. I was always naff with numbers but you strangely jogged my memory with this. In the dim distant past I used to be a graphic designer in the pre computer days and used a similar method for sizing images for pages
Many Thanks
Ron

[FRD]

Excellent formula Doug...

[Madbrit]

Doug, I echo FRD's comment. You have just provided the answer to a problem that has troubled me for ages. Thank you

Derek

[SCEtoAUX]

I am glad to help out.
One of the best things about paper models is you can change the scale with just a little work. Great for gaming layouts or comparing the size of various aircraft to one another.

[sreinmann]

Not to detract from the excellent explanation, I only have so much brain power available to math-for-free. Therefore, I refer to this page for all my scaling woes.
Online Scale Converter Tool - Scale Modelers World

[Don Boose]

It is always good to be reminded of the methodology, ronwalker, so thanks for the question.

Thanks for the info (once again), Doug, and for the link, sreinmann.

And if you will forgive me for piggybacking on this message, does anyone have a copy of Aaron Murphy's scaling chart for his models? His site is temporarily off line.

Alternatively, does anyone know the scale of Murph's Nakajima Type 91 model?

My apologies for intruding on your thread, ronwalker, but my post is relevant to the subject of scaling.

Don

[ReynoldsSlumber]

If the scale isn't listed, one method is to paste the plan as an image into a blank sheet in PowerPoint (or Keynote), note how many pixels per inch (or cm) there are for the size of the sheet, then draw a line segment as a "measuring stick" to check the dimensions of the parts in the plan.

For example, per the blue line segment shown selected here, this portion of the wing is 344 pixels long, and I know that the page resolution is 150 pixels/inch, so 344 ÷ 150 = 2.29" long. Taking all three portions of the wing together (not shown), it added up to a wingspan of 6.46", which is what I made it so that it's 1/72 scale compared to the real plane's 465" wingspan. (Note that if there's significant wing dihedral, this calculation doesn't account for that.)


If you want a different scale, you can check the overall dimensions of the pasted image itself and then re-size it proportionately. For example, the Cessna Skymaster image was 1384 pixels high at 1/72 scale, so if I wanted it to be 1/48 scale, I'd re-size the image to 1384 x 72 ÷ 48 = 2076 pixels high.

If you're upscaling and it doesn't fit on one sheet, you can paste the same sized image into multiple sheets and move the image around on each sheet until every part is printed at least once.

[ronwalker]

Hi Guys
Thanks for all the help and 'maths class' plus the link to the scaling tools as well. All really appreciated. On a side not how long do model uploads take to be approved? I uploaded a couple of rescales last night but can't see them on the downloads page!
Ron