Figuring out a scale size...Help!

[MAGIC MUFFLER]

I have a real Crackerbox Racing Boat that is 14 ft long.

There is a model I want to build that is 14 inches long.

I want to build a motor for this model ( Flathead ) then what scale motor would I look for to build????

Thank you,

Any help on this appreciated.

[Miatatom]

1/12

[MAGIC MUFFLER]

Awesome!!! Have no idea how you figured that out. Thank you

[BigTallDad]

  On 5/23/2018 at 4:40 AM, MAGIC MUFFLER said:

Awesome!!! Have no idea how you figured that out. Thank you

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comment deleted

Edited May 23, 2018 by BigTallDad

[Spex84]

If the full-size boat is 14ft long and the model is 14 inches long, that means every inch of the model is equivalent to a foot in the full-size boat. A foot is 12 inches...so that's "one to twelve", or 1:12.

168"                                            12"
_____  divide each by 14=     ______

14"                                               1"

 

 

[MAGIC MUFFLER]

Fantastic!!!  Learn something new everyday!

 

Really appreciated and thank you my Canadian friend as I'm from Canada as well but living in California.

 

Cheers

Bill

[Ace-Garageguy]

  On 5/23/2018 at 2:38 PM, MAGIC MUFFLER said:

Fantastic!!!  Learn something new everyday!

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Any "scale" is simply an expression of what fraction of the size of the real anything a model of it is.

For instance, 1:25 scale is the same as 1/25 scale, and they both mean that the real thing in question is 25 times larger than the model.

All other scales work the same way.

Let's say you have a model and you don't know what scale it is. Measure its length in inches. Then google the length of a real one, in inches (or in your case, as shown above, multiply the length of your real boat in feet by 12 to get its length in inches,  14 X 12 =168). Divide the real dimension by the length of the model (or in your case, the length of the model you want to build, 14 inches). You'll get a number. Put a "1" over it in a fraction, and you now know the scale.

168 divided by 14 = 12.  Your scale is 1/12, or 1:12.

Now, let's say you wanted to build a model of your real boat in 1:25 scale. Take the length of the real one again, 168 inches, and divide by 25. You get 6.72 inches, so that's how long a 1/25 or 1:25 scale model would be.

Edited May 23, 2018 by Ace-Garageguy

[peteski]

This is where this grade-school level math comes in handy. The stuff we didn't think we'll ever use.

[Miatatom]

  On 5/24/2018 at 1:57 AM, peteski said:

This is where this grade-school level math comes in handy. The stuff we didn't think we'll ever use.

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So true. I was a miserable math student in high school, flunking Algebra II but managed to pass calculus in college. Go figure. Never saw the need for math in my adolescent years but I learned netter later. I've really used it a lot building and racing 1 to 1s and model cars too. I learned as an instructor at a nuclear plant for a student to "get it", you've got to relate it to real life. Doesn't matter what you're teaching.

[Ace-Garageguy]

  On 5/25/2018 at 4:17 AM, Miatatom said:

So true. I was a miserable math student in high school, flunking Algebra II but managed to pass calculus in college. Go figure. Never saw the need for math in my adolescent years but I learned netter later. I've really used it a lot building and racing 1 to 1s and model cars too. I learned as an instructor at a nuclear plant for a student to "get it", you've got to relate it to real life. Doesn't matter what you're teaching.

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I agree heartily.

Though I was fine with everything through algebra, I struggled with calculus my first quarter. The instructor was a pure-math enthusiast, and had little interest in helping us grasp how it could be applied to real-world problem solving.

Once I understood how it could be used as a tool, everything changed.

[Miatatom]

  On 5/25/2018 at 1:15 PM, Ace-Garageguy said:

Once I understood how it could be used as a tool, everything changed.

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That light bulb moment!

[Chariots of Fire]

That's why I model in 1/25 scale.  Since there are 25.4 mm in one inch, using a metric ruler is pretty well on the mark.  That 0.4mm doesn't really make that much difference for most of what we do so to make things easy use a metric ruler and for every full size inch call it a millimeter.  A 145" wheel base in real life would be 145 mm!

[SSNJim]

A wheelbase of 145" would actually be 147.32 mm in 1/25. Calling an inch one millimeter works fine for smaller measurements but for larger measurements the 1.5% or so difference starts to add up.

[Bainford]

A more accurate method of scaling when working in 1/25 scale is using .040" to represent 1''. This makes the math easy when scaling parts; .020" = 1/2 inch,  .010" = 1/4 inch,  .005" = 1/8 inch, etc.  .080 = 2 inches,  .120" = 3 inches, etc. It makes for an excellent scaling method when scratchbuilding.

[Ace-Garageguy]

  On 5/29/2018 at 1:25 PM, Bainford said:

A more accurate method of scaling when working in 1/25 scale is using .040" to represent 1''. This makes the math easy when scaling parts; .020" = 1/2 inch,  .010" = 1/4 inch,  .005" = 1/8 inch, etc.  .080 = 2 inches,  .120" = 3 inches, etc. It makes for an excellent scaling method when scratchbuilding.

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That's a good rule-of-thumb to put on a sticky note in plain view over the bench.