Scale Calculator? How about this one.

[Ace-Garageguy]

I'm sorry if this seems "mean", but understanding "scale" only requires an understanding of fractions and division. This is fifth-grade math. How can anyone functioning in society NOT have these basic elementary-school skills?

Edited April 18, 2014 by Ace-Garageguy

[Skip]

I've used a standard old calculator forever, most of my measurements are made with either dial or digital calipers or a machinists rule (hundredths). So converting the measurements to decimal just makes the whole scaling up, down all that much easier.

Accuracy normally boils down to how many significant digits beyond the decimal point you wish to take it. Even with digital calipers styrene has enough give to it that there could be some loss of accuracy as no two people measure with the same amount of pressure. In scale modeling hundredths of an inch is probably more than accurate, unless it's metal thousandths are just overkill.

The key to accurate number crunching is to allow the significant digits to float throughout the calculations, then round the output to the appropriate significant digit, which would be the last mathematic calculation. Most decent calculators can be set up to float the decimal point, they do it throughout the calculations though; so there could be a minute amount of loss of accuracy.

[MrObsessive]

  On 4/18/2014 at 1:17 PM, Ace-Garageguy said:

I'm sorry if this seems "mean", but understanding "scale" only requires an understanding of fractions and division. This is fifth-grade math. How can anyone functioning in society NOT have these basic elementary-school skills?

Sadly Bill, with our education system in this country today, it's no wonder that people don't understand basic things such as math, reading and writing. I could go on and on, but look how folks today communicate in the written word. I read a story the other day in the local news that had many spelling errors------this apparently written by a "professional" that's supposed to know the basics of the English language, and have SOME understanding of good sentence structure.

I blame it on the general "dumbing down" of society that's been in full swing since the '80's.

[Skip]

  On 4/18/2014 at 1:17 PM, Ace-Garageguy said:

I'm sorry if this seems "mean", but understanding "scale" only requires an understanding of fractions and division. This is fifth-grade math. How can anyone functioning in society NOT have these basic elementary-school skills?

Bill, it's called "Dumbing Down". Johnny or Susie can't understand how to do it so they stopped teaching what kids didn't understand. That's why all the standardized testing is huge in the world of education right now. As in the U.S. Education system is trying to play catch up with the rest of the world who refused to stop teaching the basics, they just found better methods to teach kids in ways they understand. (My wife is a Teacher, I hear about this stuff almost every day!)

[Agent G]

  On 4/18/2014 at 1:31 PM, MrObsessive said:

Sadly Bill, with our education system in this country today, it's no wonder that people don't understand basic things such as math, reading and writing. I could go on and on, but look how folks today communicate in the written word. I read a story the other day in the local news that had many spelling errors------this apparently written by a "professional" that's supposed to know the basics of the English language, and have SOME understanding of good sentence structure.

I blame it on the general "dumbing down" of society that's been in full swing since the '80's.

  On 4/18/2014 at 1:38 PM, Skip said:

Bill, it's called "Dumbing Down". Johnny or Susie can't understand how to do it so they stopped teaching what kids didn't understand. That's why all the standardized testing is huge in the world of education right now. As in the U.S. Education system is trying to play catch up with the rest of the world who refused to stop teaching the basics, they just found better methods to teach kids in ways they understand. (My wife is a Teacher, I hear about this stuff almost every day!)

What they said.

X2

G

[Harry P.]

The reason I made such a point of explaining that any calculator can figure scale, and no special "scale calculator" is needed, is that I have seen posts made here in the past (not in this thread) from guys who literally don't understand what "1/25 scale" means! They seem to think that there's some sort of arcane special formula that you need to know in order to convert full scale measurements to scaled down measurements or vice versa, and that a specialized "scale calculator" is needed. Of course, as I (and others) have explained, the concept of "scale" is basic grade school stuff. A 1/25 scale model is 25 times smaller than the real thing, or to say it the other way, the real thing is 25 times bigger than a 1/25 scale model. There's no mystery or special calculator needed.

[Aaronw]

Yes, fractions are 5th grade math, and they are largely left in the 5th grade if you don't have a job or hobby that requires a common use of fractions (baking, carpentry, drafting). When I started testing for fire department jobs at the age of 24 I encountered math involving fractions again for the first time in many years. I had to get my mother (a teacher) to go over math involving fractions because by that point in my life I had completely forgotten all but the most basic points of working with fractions.

I know more than one adult who has had to get their 5th grader to explain fractions to them again, so they can understand the child's homework. Use it or lose it.

[ScaleDale]

Although most of us use the fraction 1/25 to express scale, actually it's 1 : 25. Scale is a ratio of one to another. 1 = 25 or, for the Big Boys, 25 = 1. You can't turn a fraction around like that but you can with scale. Look at your kit boxes. Most, but not all, are n : nn.

In short, while a model may be 1/25 of the full size version, it's built in a scale of 1 inch equals 25 inches.

Disclaimer: I have slide rule era drafting training.

Dale

Aaron: Parents can't understand their children's homework because the methods used to teach math today are totally incomprehensible. I taught Special Ed for 22 years and just no one bases math off concrete examples anymore. It's all concept first. Followed my mass confusion.

Edited April 18, 2014 by ScaleDale

[Harry P.]

  On 4/18/2014 at 3:46 PM, ScaleDale said:

In short, while a model may be 1/25 of the full size version, it's built in a scale of 1 inch equals 25 inches.

Yes, exactly!

A 1/25 scale model is one twenty-fifth the size of the real car. The real car is 25 times larger than the model. One inch on the model equals 25 inches on the real car. Twenty-five inches on the real car equals one inch on the model. It's all the same fraction... 1/25. The "scale" of a model is simply the fractional size of the real car that the model is.

[sjordan2]

All of this is well and fine, but if you just want a free, fast enter-and-click converter, just go to the bottom of this page and bookmark it:

http://www.scalemotorcars.com/forum/forum.php

[Tom Geiger]

Man, this gang will argue about anything!

As Harry said, there are guys who haven't figured out how to get to 1/25 scale. A lot of them just avoid math because it's supposed to be a hobby and math is.. well, work! And there will always be that math geek who will tell them all that geometry is fun and easy, only making them feel worse.

Part of why scale rulers have been used in Engineering are to make work easier and faster, but also to avoid making math mistakes. And a lot of disciplines work primarily in inches to avoid errors in converting feet into inches. I started out drafting piping for process plants. Pipe sizes are always in inches. And any length under 3 feet is always displayed as inches. I have worked with office furniture for eons. When designing space and cubicles, it's all done in inches. So there is no such thing as a 3 foot wide panel, it's a 36" panel... actually it would be shown on a drawing as a 36x72 (if the height was 72"). And one of the major manufacturers, Steelcase actually based it's products on 5" increments. So you'd have 25", 30" and 35" wide panels. No need for feet when adding those up!

All I can say is that when I did demos on the 1/25 scale ruler, guys got downright giddy that they could work in scale. And anything that helps guys build better models is okay with me.

[Belugawrx]

This should be pinned in "Tips and Tricks"

[sjordan2]

  On 4/22/2014 at 1:41 AM, Belugawrx said:

This should be pinned in "Tips and Tricks"

We used to have an excellent series of pinned Tips and Tricks in that section, on the most commonly asked questions, but it was removed for reasons that I can't explain.

Edited April 22, 2014 by sjordan2

[fantacmet]

  On 4/18/2014 at 1:43 PM, Harry P. said:

no special "scale calculator" is needed, ................ There's no mystery or special calculator needed.

I actually do agree with you, and you are right, if you have access to run this software, you have access to everything you need(unless you don't know the actual scale of a specific train scale which are labeled in letters and only if you don't have net access), however for those that have trouble using calculators(for whatever reasons), or are otherwise mathematically challenged, or have trouble doing conversions from one scale to another, that's one of the reasons I made this. The other main reason is, to prove to myself I can actually program something that won't crash. Sadly enough this is the first bit of software I've ever created, that did something useful, that didn't crash. I also wanted to contribute something since I don't have the ability to do any type of sculpting to create something for casting in resin. I just copy occasional kit parts for my own personal use, that aren't sold separately.

Now if someone doesn't know how to use the digital calipers or ruler to go with it, well...........................

Reality is, even though I have this software and it's on my computer, I just use the regular calculator. I failed my college algebra class. Twice. However interestingly enough I not only got a 4.0 in advanced physics I got 100% on everything from the midterm on. so I'm a bit of an oddball to say the least.

[Art Anderson]

  On 4/15/2014 at 9:37 PM, Ace-Garageguy said:

How about this one.

Dollar store calculator.

Enter full size dimension.

Divide by scale denominator. (For the math challenged, this would mean divide by 8 to get 1/8 scale, etc).

Pretty basic.

Bill: POIFECT!!! For that matter, I learned a long time ago that it became very easy to scale things down once I fixed in my mind "40-thousandths of an inch in 1/25 scale equals an inch in 1:1, which makes the common fractions of an inch pretty simple--don't often use even a piece of paper and pencil to calculate dimensions in scale any more. (I have been known, however, to consult my Dollar Store hand held calculator on occasion, just to confirm the math though!)

Art

[southpier]

will those dollar calculators figure tips in the restaurant?

I like to be generous and leave 5%

[Pete J.]

I can see a use for a scale ruler(I have several from my drafting days) in that it eliminates a step but a scale calculator??? Do you need a change calculator too? Lets see, she gave me back a quarter, a dime and a nickel, but the calculator says it should have been three dimes and two nickels.

Edited October 7, 2014 by Pete J.

[Harry P.]

  On 10/7/2014 at 11:13 AM, southpier said:

will those dollar calculators figure tips in the restaurant?

I like to be generous and leave 5%

If you ever go back to that restaurant, aren't you afraid they'll spit in your food?