Math 101

der Vogelfänger · Post by **der Vogelfänger** » Sat Jul 21, 2007 1:24 pm

The question always arises: how big or small will a particular airplane (or tank/truck, etc.) be in a certain scale. By turning to simple math one will be able to answer his/her own question as to size. I would like to post the following multipliers for various scales for quick problem solving input.....

The following multipliers are arrived at by using the one-foot or 12" (basic) measure, and, for example let's use 1/18 scale....divide 12" by 18" and the result = 0.66666 or 0.67. To find the size of an airplane, let's take the A6 Intruder as an example......

A6 wingspan=53'....53'x0.67=35.51" or the wing span in 1/18 scale;
A6 length=54'7"(7"=.58")...54.58'x0.67=36.57" or the length in 1/18 scale;
A6 height=15'7"...15.58x0.67=10.44" or the height in 1/18 scale.

The same can be calculated for other scales using these multipliers:

1/18 = 0.67
1/32 = 0.375
1/48 = 0.25
1/72 = 0.167
1/144 = 0.0833

After a few calculations it is evident that the scale ratio (1/18, 1/32, etc.) in a inverse porportion to the size of the object...ie., the larger the denominator the smaller the (object) airplane.

Hope this will help one and all in their "how big will it be" hopes/dreams/questions.

dV

Post by **aferguson** » Sat Jul 21, 2007 3:16 pm

i suspect you'll need to re-write that in english for some board members.

A simple shorthand for converting to 1/18 scale is to remember that one inch on the model is equal to a foot and a half on the real thing. So a 1/18 model that's 10 inches represents 15 feet. Just divide the models dimension in half and add that to the original dimension (this is the same as multiplying by 3/2) and remember that the answer is in feet.

eg a plane with a 24 inch span represents an actual wingspan of 36 feet (24/2=12, then add 12 to 24 (the original dimension) and you get 36 and remember the answer is in feet).
a tank with a length of 18 inches represents a vehicle 27 feet long.

Going the other way, a 30 foot object would be 20 inches long in 1/18 scale (so just multiply the actual objects dimension by 2/3 and remember the answer is in inches).

eg a wingspan of 40 feet would be 26.7 inches (40 x 2/3)
an 80 foot PT boat would be 53.3 inches (80 x 2/3)
a 221 foot U-boat would be 154 inches (221 x 2/3)

kevrut · Post by **kevrut** » Sat Jul 21, 2007 3:23 pm

The way I figure it isn't too much different. I just figure how many inches long the 1:1 object is and convert that into inches.

Something 30' long is 360" long. Divided by 18 = 20".

Kevin.

pickelhaube · Post by **pickelhaube** » Sat Jul 21, 2007 4:19 pm

Kevin is right (and the easist way).
Plane or tank (?) is 35 feet 4 inches long
So:
35x12=420
420+ 4=424
424 divided by 18 =23.55 inches BINGO

Post by **aferguson** » Sat Jul 21, 2007 4:28 pm

i think we need a poll to decide whose way is the best.

Killerf6 · Post by **Killerf6** » Sat Jul 21, 2007 5:24 pm

Or you could just wait for the particular item to come out in 1/18 and use a tape measure.

der Vogelfänger · Post by **der Vogelfänger** » Sat Jul 21, 2007 6:35 pm

aferguson wrote:i think we need a poll to decide whose way is the best.

I was not writing out my figures to create a "who's-method-is-best" contest.....merely to help in figuring sizes. Of coarse there are back-door-methods/different calculations which can be used to help one gain a valid answer, or one to "fit" the moment. Sorry that my straight-forward approach was misunderstood....dang, it seemed pretty simple to me*.

.....I still seek to write the perfect-in-every-respect-post. To use other than English, I really like this phrase: Übung macht den Meister!

dV
FLYNAVY73
:blueangel:

*Let's see, find your multiplier on the list and multiply the vehicle size in feet/inches, and your product is your answer in inches. One function to yield an answer. Thought provoking, ja?! German Engineering in das Hausssssssss

.

Credit is due for the other methods, too....like being back in "class" where we learn from each other.

pickelhaube · Post by **pickelhaube** » Sat Jul 21, 2007 7:00 pm

der Vogelfänger wrote:
aferguson wrote:i think we need a poll to decide whose way is the best.
I was not writing out my figures to create a "who's-method-is-best" contest.....merely to help in figuring sizes. Of coarse there are back-door-methods/different calculations which can be used to help one gain a valid answer, or one to "fit" the moment. Sorry that my straight-forward approach was misunderstood....dang, it seemed pretty simple to me*. .....I still seek to write the perfect-in-every-respect-post. To use other than English, I really like this phrase: Übung macht den Meister!

dV
FLYNAVY73

*Let's see, find your multiplier on the list and multiply the vehicle size in feet/inches, and your product is your answer in inches. One function to yield an answer. Thought provoking, ja?! German Engineering in das Hausssssssss .

Credit is due for the other methods, too....like being back in "class" where we learn from each other.

Your way makes my head hurt. That happens when I have to think . The way I do it no thinking needs to be applied.

MG-42 · Post by **MG-42** » Sat Jul 21, 2007 7:02 pm

----> Like , over my head ? ...

VMF115 · Post by **VMF115** » Sat Jul 21, 2007 7:07 pm

der Vogelfänger must be thinking in german again.

Post by **aferguson** » Sat Jul 21, 2007 7:19 pm

derV: it's not a contest at all...my method is clearly the best.

I wasn't trying to undermine your explanation, being somewhat good at math myself, i've come to understand that most people aren't, and trying to explain it just confuses them more. So i offered my 'shorthand' method, which i was hoping is a simplified way of looking at it.

FieroDude · Post by **FieroDude** » Sat Jul 21, 2007 7:20 pm

Actually, Jim's calculation is an easy shortcut I hadn't thought of. I am used to the method of multuplying by 12 to get total inches, then dividing by 18 (and if it's really big, dividing by 12 again, to get feet--somehow, knowing a modern aircraft carrier would be 784 inches long doesn't really put it in perspective, while 65 feet 4 inches I can live with). But for a quick and easy way to get a result, it works great!
Now about those metric using folks out there, complicating everything with an extra step...

Plane Nuts · Post by **Plane Nuts** » Sat Jul 21, 2007 9:35 pm

FieroDude wrote: Now about those metric using folks out there, complicating everything with an extra step...

Not an extra step. Just multiply by 25.4. Unless it's in feet, then divide by .3048.

Oy vey.....is this really a topic??? Aferg: We need a pole stat... Wait, poll stat!!!!!!!

Edit: BTW, yes I know my math is wrong. Didn't intend to do it right in the first place.

FieroDude · Post by **FieroDude** » Sat Jul 21, 2007 9:44 pm

See, an extra step

Metric isn't so bad--I went to school in the days when it looked like the US might go metric, plus all my chemistry and physics claases were in metric, plus all the time spent in Canada and overseas.

Now we need to figure out the conversion factors fcr points/picas and to be really different, for cubits! Any other really obscure measurements I am forgetting?

pickelhaube · Post by **pickelhaube** » Sun Jul 22, 2007 5:29 am

When scaling off of a model or what not metric is easier if you can get the original measurement in metric. It is done 1/10 not 1/8 or 1/16 wich starts getting tricky.
Say you have a 1/32 scale Wildcat the length is right at 31 cen. or 310 mm.
The scale is 32 so you use that number.
32x31=992 OK now you want to convert that to 1/18 scale so:
992 divided by 18=55.1 cent or 55 cent and 1 mm.

der Vogelfänger · Post by **der Vogelfänger** » Sun Jul 22, 2007 7:04 am

pickelhaube wrote:When scaling off of a model or what not metric is easier if you can get the original measurement in metric. It is done 1/10 not 1/8 or 1/16 wich starts getting tricky.
Say you have a 1/32 scale Wildcat the length is right at 31 cen. or 310 mm.
The scale is 32 so you use that number.
32x31=992 OK now you want to convert that to 1/18 scale so:
992 divided by 18=55.1 cent or 55 cent and 1 mm.

Yeowww....I had not even considered the metric measures....so much for thinking in German again; that just proves that I am only half Deutscher not full, otherwise metric would have been my first choice

Good input from all the above posts!! This "Professor" is, too, a student

dV

der Vogelfänger · Post by **der Vogelfänger** » Sun Jul 22, 2007 7:06 am

aferguson wrote:derV: it's not a contest at all...my method is clearly the best.

I wasn't trying to undermine your explanation, being somewhat good at math myself, i've come to understand that most people aren't, and trying to explain it just confuses them more. So i offered my 'shorthand' method, which i was hoping is a simplified way of looking at it.

My thoughts exactly, but in reverse

...good input from one and all!

Danke,

dV

blurx7 · Post by **blurx7** » Sun Jul 22, 2007 7:12 am

FieroDude wrote:See, an extra step
Now we need to figure out the conversion factors fcr points/picas and to be really different, for cubits! Any other really obscure measurements I am forgetting?

Sheesh! I halfway expect someone to next start into the methodology for calculating the internal volume of 1/18 models ( just in case someone wants to turn their Old Crow into a jello mold)

But seriously, thanks for the discussion. I always learn things here!

pickelhaube · Post by **pickelhaube** » Sun Jul 22, 2007 10:15 am

FieroDude wrote:See, an extra step

Metric isn't so bad--I went to school in the days when it looked like the US might go metric, plus all my chemistry and physics claases were in metric, plus all the time spent in Canada and overseas.

Now we need to figure out the conversion factors fcr points/picas and to be really different, for cubits! Any other really obscure measurements I am forgetting?

You forgot G units

Or is that another site?

Small Scale Military Headquarters

Math 101

Math 101

xd