Changing scale for projects - how to do the math?

Actually, it's 133% of the S-Scale size.  20.83/15.62 = 1.3335

@gunrunnerjohn posted:

Actually, it's 133% of the S-Scale size.  20.83/15.62 = 1.3335

Thanks - wow I really need a math refresher!

I noticed you were working on the Jeep card.  I happened to be working on that as well.  I did a test print of the original size and then measured and scaled it up to O-scale.  The real JEEP was 10' 10" long or roughly 2.75" in O-scale.  Scaling up the model got me to an O-scale JEEP.

It's good enough that I think I'll invest in the olive green filament and print some for flatcar loads.  I actually may print the canvas top separately in a slightly different color, and print the tires in black.

I can fit three of the O-scale cards on my build plate.  I may remove them from the card so I can print them four at a time.

I regularly do the math to convert 1:1 in feet and inches to 1:48 in millimeters.  Long story if you haven't followed my posts on the forum.  I set up a cheat sheet in Excel to do the math for me for converting both directions.  I got tired of writing out the algebra on it.  My 28-year-old daughter who teaches high school calculus would be appalled. 

There is a handy chart right here: 3d.ogaugerr.com/printing101

@Darrell posted:

There is a handy chart right here: 3d.ogaugerr.com/printing101

Thanks Darrell - very handy indeed!

Here ya go...from the OGR 3D Catalog website.

SCALE CONVERSION RATIOS

FROM TO	#1 scale	O scale	S scale	OO scale	HO scale	TT scale	N scale	Z scale
#1 scale (1:32)		150%	200%	238%	272%	375%	500%	688%
O scale (1:48)	67%		133%	158%	181%	250%	333%	458%
S scale (1:64)	50%	75%		119%	136%	188%	250%	344%
OO scale (1:76)	42%	63%	84%		115%	158%	211%	289%
HO scale (1:87)	37%	55%	73%	87%		138%	184%	253%
TT scale (1:120)	27%	40%	53%	63%	73%		133%	183%
N scale (1:160)	20%	30%	40%	48%	43%	75%		138%
Z scale (1:220)	15%	22%	29%	35%	40%	55%	73%