Formula for HO Scale

[filmtrain]

Hey Folks

Excuse me for being math challenged but is there a simple formula for making measurements in HO scale?

For instance if my sidewalk is 3 feet wide outside my house and I want to model it in HO, how do I figure out how wide it should be?  Thank you for the help.  Remember math challenged so it needs to be easy which I am sure it.  Math is why I majored in media, not engineering.

[Conrail Quality]

First, convert it into inches by multipling it by twelve (you could leave it as feet, but you will get a much messier answer). Then, divide by 87 (HO scale is 87 times smaller than the real thing). That will come out to about 0.414 inches in HO scale.

Timothy

[SteamGene]

The EASIEST thing to do is to buy a ruler marked off in HO scale feet and you just measure 3 HO scale feet with it.  But HO is essentially 1:87, so for your three foot side walk, divide 3 by 87 to get .41 inches, or a bit less than 1/2 inch wide.  
Gene

[Yampa Bob]

As explained, linear measurements such as length or width are pretty straight forward, just use the factor of 87. 

For other units of measurement, such as volume and weight, it becomes a "cubic" function.  For example, a 100 ton car will weigh only 4.86 ounces in HO scale.

The formula:  100 ton X 2000 lbs X 16 ounces divided by (87X87X87)= 4.86 ounces.

Here is an excellent page for "Scale and Gauge Definitions".
http://www.spec2000.net/rr_site_pages/rr_scale_dfn.htm

(Turn your volume down if the kids are asleep)

Bob

[TonyD]

Easy in metric. Less typing too. 3 & 1/2 millimeters to one HO foot. Your sidewalk is 10.5 mm's wide.

[kevin2083]

Or, you could multiply by 0.011494252873563218390804597701149
;

[Yampa Bob]

You don't want to hear my opinion on metric fasteners. 

Bob

[Woody Elmore]

HO scale is 3.5 mm to the foot - this is a tad bigger than 1/8th inch and a tad smaller than 9/64th. If you take your actual measurement and multiply it by the hyperbolic sine of pi radians (make sure you set your calculator to radians) you'll get some silly number.

RULE NUMBER ONE - no matter what scale you use get an NMRA track gauge and a scale ruler. Than you won't have to submit yourself to reading stupid answers posted by wise guys like myself!

HO scale rulers are available from a number of sources - try Walthers.

[Yampa Bob]

I like visiting Crain's site for the cool music. 

"Yikes, RADIANS AGAIN"....

Bob

[adari]

Here is a cool link:

http://www.ztrains.com/pages/workshop/calculator/calculator.html

Adari

[Yampa Bob]

I'd like to have a dollar for every new "calculator" that pops up on the net. What happened to good old mathematics?

Hand held calculators are pretty well accepted these days, but at least with them you still have a feel for the math process. 

Since I only model HO, I have only one scale ratio to remember,  87.  Whether linear, squared or cubed, that's all I need.

Bob

[grumpy]

I tell you it really gets tough when you model G-scale and H.O like I do. The sizes are so close that I can never decide what to buy. I buy both just to make sure I am covered.
Don

[TonyD]

OK, that's enough of this, you guys go back and work on your trains, or you'll all stay after school....

[Yampa Bob]

Let's see here, HO is about 1" wide, G is about 4" wide....

Don.....uh.....lol...Can I loan you my white cane?

Bob