Scale Difference

[Tom Geiger]

As said a lot of times it comes down to “the look”.. does it look right? There are always sacrifices made in scale due to thickness of materials or getting it all to fit together. Sometimes it’s done for the look, there are times that dead accurate in scale doesn’t look right!

Here’s 1/24 and 1/25 across from each other, you can see the difference. We designed this off the center 

Edited October 15, 2020 by Tom Geiger

[Ace-Garageguy]

30 minutes ago, peteski said:

... but since a wheel diameter is mentioned, there are other things to consider.  A 14" car wheel's visible outside diameter is actually 15.5".  So that is what you need to use for calculation.

Just to avoid confusion...the 14 in a 14" wheel refers to the diameter of the tire sealing bead, which is also the diameter of the hole in the center of the tire.

As tires are "stretched" over slightly larger rims so they don't pop off when they're inflated, this makes perfect sense, and the outer rim diameter is usually about 1.5" larger than the diameter of the hole in the center of the tire that seals against the rim.

SOME model car wheels and tires maintain a semblance of the real relationship between outer rim diameter and tire center diameter, and some don't.

To get really accurate looking wheel/tire setups on your model (or to know what nominal wheel size your model wheel would be in reality) it's necessary to measure the outside diameter of your model rim, multiply by the denominator of whatever scale you're working in (EXAMPLE: if you're working in 1/25 multiply by 25 to give you the full-size outer diameter), and then subtract 1.5" to get the nominal wheel size.

But just remember that in general, all "scale" means is the fraction of the size of the real car or part the model car or part will be. To get the correct scale measurement of any part, in any scale, just divide the dimension of the real part by the denominator of whatever scale you're working in.

[Straightliner59]

12 hours ago, peteski said:

Yes, multiplying by 0.04 or dividing by 25 will yield the same result. In math there are usually multiple ways to arrive at the same results.  To me it seems more intuitive to use the division method (since you are directly plugging in the scale ratio number into the equation, rather than its reciprocal).   Not many average people know off the top of their heads that reciprocal of 25 is 0.04.

I've always had an easier time with multiplication than division! 🙂 Plus, it's easy to remember that .040" strip stock is 1", in 1/25 scale, therefore, .005"=1/8", .020"=1/2", etc. I've gotten to where I just think that way, when I'm building. But, you're right. It doesn't matter how you get there!

[TransAmMike]

Phew!!!!!!!   I didn't think I'd get you guys' this involved but I appriciate the enthusiasm.  Thanks very much.

[Can-Con]

Here in Canada, it's a lot simpler. 

1 inch in 1/25 = 1 millimeter.  😉

I can actually do the conversion in my head. 😄

[peteski]

8 hours ago, Straightliner59 said:

I've always had an easier time with multiplication than division! 🙂 Plus, it's easy to remember that .040" strip stock is 1", in 1/25 scale, therefore, .005"=1/8", .020"=1/2", etc. I've gotten to where I just think that way, when I'm building. But, you're right. It doesn't matter how you get there!

LOL!  That's where calculators come in - just as easy to divide as it is to multiply.  They can be had at a dollar store, or even any smart phone, tablet, or a PC have those built in.

I  also see where you are coming from - fine if you are a single-scale modeler it is easy to just remember couple of figures..  But if you work in multiple scales (I work in 1:6, 1:8, 1:12, 1:16, 1:24, 1:25, 1:32, 1:43: 1:64, and 1:160), so I just use a calculator.  I have few of the tiny ones from Staples always handy on my workbench.  I have too many things on my mind to remember bunch of scale related numbers.  I do remember that 1mm is 0.039".

[Straightliner59]

5 minutes ago, peteski said:

LOL!  That's where calculators come in - just as easy to divide as it is to multiply.  They can be had at a dollar store, or even any smart phone, tablet, or a PC have those built in.

I  also see where you are coming from - fine if you are a single-scale modeler it is easy to just remember couple of figures..  But if you work in multiple scales (I work in 1:6, 1:8, 1:12, 1:16, 1:24, 1:25, 1:32, 1:43: 1:64, and 1:160), so I just use a calculator.  I have few of the tiny ones from Staples always handy on my workbench.  I have too many things on my mind to remember bunch of scale related numbers.  I do remember that 1mm is 0.039".

Don't tell anybody, but, I have the calculator right down there, in the toolbar! 😆

[peteski]

17 minutes ago, Straightliner59 said:

Don't tell anybody, but, I have the calculator right down there, in the toolbar! 😆

I knew it!!

[landman]

This is roughly what the difference is. As mentioned above it varies. the '70 is 1/24 while the '69 is 1/25, the same between the '66 & '67. Hope this helps.

Edited October 17, 2020 by landman

[Tom Geiger]

On 10/15/2020 at 10:04 AM, Straightliner59 said:

I've always had an easier time with multiplication than division! 🙂 Plus, it's easy to remember that .040" strip stock is 1", in 1/25 scale, therefore, .005"=1/8", .020"=1/2", etc. I've gotten to where I just think that way, when I'm building. But, you're right. It doesn't matter how you get there!

Which is why you need a scale ruler.  No math at all.  Measure 18 inches on your 1:1 car, then measure off 18 inches using this ruler against your model.  We also kept it all in inches to avoid the inches to feet math. Several industries do this in real life.. for instance office furniture. 

Scale rulers are extensively in industry. Coming from a drafting and design background, when I got into model cars, immediately I sought out a scale ruler. I couldn’t do scratch building without it!
 

[TransAmMike]

Looks like I really got you guys' going with my question about scale.  I was hoping someone would post pictures of same year cars in the different scales and you did Pat.

[Bills72sj]

Here is a pic of my Mopar E-body "Rainbow"

Pink 1:24 Revell AAR 70 Cuda

Red 1:25 AMT 70 Challenger R/T SE

Orange 1:25 71 Challenger conversion from an AMT 70 Challenger

Yellow 1:25 AMT 70 Challenger convertible

Green 1:24 Revell 71 Hemi Cuda

Blue 1:25 Lindburg 72 Challenger

Purple 1:25 AMT 70 Challenger R/T convertible

You can see the two Revell's are ever so slightly bigger in spite of the real world shorter wheel base of a Cuda vs. a Challenger.

 

[89AKurt]

My experience......
1/24 resin wheels, mixed with 1/25 wheel backs, the tires are Italeri 1/24 that were Dremel ground bigger on the inside.  They are not true to scale, but looks good enough to me!

I rescued a 1/24 Corvette that was missing the engine, had the 427 in the parts box for decades.  Only after I painted everything, and was putting the chassis into the body did I discover a problem.  Searched for the '39 Chevy and found out it's 1/25.  So I had to again use the Dremel to thin down the tunnel, and adjust the firewall.  So I say it's a Huge Block. 😅

[TransAmMike]

"Huge block" , good one Kurt.🤣😂🤣

[bisc63]

On 10/15/2020 at 2:32 PM, Can-Con said:

Here in Canada, it's a lot simpler. 

1 inch in 1/25 = 1 millimeter.  😉

I can actually do the conversion in my head. 😄

I've been using that way of measuring my car parts for a few years now, and find it works well enough. Most rulers and tape measures here now have one edge in metric, so 1 millimeter = 1 inch is easy to work with. It works great for small parts, but for longer lengths (wheelbase measurements, etc) you begin to come up just a bit short, and have to make adjustments, and/or do the math!

[Vince Nemanic]

I vaguely remember reading back in the '80s that the earliest promos ordered by GM were required to fit into a standard GM parts box. The problem was tht the box was too narrow to hold the width of an accurately-scaled 1/25 promo. so the promos were made a bit too narrow. Once people were used to the fudged proportions, the companies began to include engines, but since the chassis were too narrow, the engines were made narrow also. Companies like Monogram that never made promos just accurately scaled their bodies and parts accurately, which resulted in Monogram engines nd other parts didn't fit the 1/25 kits. I think the person who wrote that was a guy named Tim Boyd. Did I remember that right, Tim?

[Straightliner59]

13 hours ago, Tom Geiger said:

Which is why you need a scale ruler.  No math at all.  Measure 18 inches on your 1:1 car, then measure off 18 inches using this ruler against your model.  We also kept it all in inches to avoid the inches to feet math. Several industries do this in real life.. for instance office furniture. 

Scale rulers are extensively in industry. Coming from a drafting and design background, when I got into model cars, immediately I sought out a scale ruler. I couldn’t do scratch building without it!
 

I have three of them! An aluminum Murphy's Rule, a clear, flexible Ivarule, and one similar to yours, but, without the logo. They are definitely handy!

[Tom Geiger]

11 hours ago, Straightliner59 said:

I have three of them! An aluminum Murphy's Rule, a clear, flexible Ivarule, and one similar to yours, but, without the logo. They are definitely handy!

Model car guys fall into three camps.. 

First are the guys who are into math and are pleased that they can calculate out every dimension.

Second are the guys who don’t build to scale and approximate because they think scaling is too complicated.

And third, the camp that includes you and I using scale rulers.

This comes naturally to me as a former draftsman, where we used scale rulers daily. We designed and produced this scale ruler as a free show give away in the hope that more people would discover just how easy it is to build in scale by using a scale ruler. We made it all inches to eliminate the math in converting inches to feet, as done in several industries. Also we built in a nifty centering device I find very handy.

[Reegs]

On 10/14/2020 at 12:41 PM, Ace-Garageguy said:

The result has been some oddly "scaled" kit parts. Examples include a ridiculously undersized (about 1/32 scale) engine in the "new tool" 1/25 scale AMT Ala Kart kit. el.

How much undersized? The engine in the Ala Kart was a  1954 266 ci Dodge Red Ram.  I think it was only 27" long? Maybe use it as a start to the Adams & Enriquez junior fueler?

Edited October 18, 2020 by Reegs

[Ace-Garageguy]

4 hours ago, Reegs said:

How much undersized? The engine in the Ala Kart was a  1954 266 ci Dodge Red Ram.  I think it was only 27" long? Maybe use it as a start to the Adams & Enriquez junior fueler?

The engine in the original Ala Kart kit, tooled and released in the early 1960s, when people could still measure things reasonably accurately in elementary school, was very close to being correctly scaled.

The engine in the totally re-tooled kit was, as I said, approximately 1/32 scale. Pathetic...especially because the original engine fits in the "new tool" engine bay just fine, so there was no reason to shrink it other than incompetence. SEE: part TWO below for comparison photos

 

 

Edited October 18, 2020 by Ace-Garageguy

[peteski]

Here are some Camaro bodies.

Here is the original post where I used that photo: http://www.modelcarsmag.com/forums/topic/121020-the-124-scale-history-story/?tab=comments#comment-1757672

Edited October 18, 2020 by peteski

[Can-Con]

10 hours ago, Tom Geiger said:

Model car guys fall into three camps.. 

First are the guys who are into math and are pleased that they can calculate out every dimension.

Second are the guys who don’t build to scale and approximate because they think scaling is too complicated.

And third, the camp that includes you and I using scale rulers.

This comes naturally to me as a former draftsman, where we used scale rulers daily. We designed and produced this scale ruler as a free show give away in the hope that more people would discover just how easy it is to build in scale by using a scale ruler. We made it all inches to eliminate the math in converting inches to feet, as done in several industries. Also we built in a nifty centering device I find very handy.

I fall into the 4th Tom.

I don't worry too much about scale and don't measure or do the math because there's no point.

Even if something I'm working on measures out correctly, some other part of it won't. 

If something looks "right", then it looks right. No amount of measuring will change that. 

I'd rather build something that looks right than worry about fractions of inches and never get anything finished.

Not for everyone, I know and that's all right. It's how I do it. Other people do things differently and that's all right too.

[Reegs]

Thanks.

Next question - what the hell were they thinking? No, you don't need to answer.