Converting scale; 1/28 to 1/25-24

[aurfalien]

Hi,

Curious if any one has scaled up a body before.

I imagine splicing/grafting some styrene into various body parts but curious if any one has done this successfully.

[Snake45]

What exactly is it that you're trying to do?

[aurfalien]

Welp, I was thinking to get an Otaki 1/28 Ferrari 712 CanAm and scale it up a bit to 1/25-1/24.

I'm only interested in the body as I've extra stuff to do everything else.

[MrObsessive]

Man, that's an AWFUL lot of work to go through! I can tell you from having to "stretch" parts to suit a larger body, you might run into problems with symmetry, and since you're not practiced at this sort of thing, might it be better to modify an existing car (something similar) in that scale?

[Ace-Garageguy]

As Bill Geary says, it's a lot of work if you want accuracy.

Consider: Assume a body width of 5 feet, or 60 inches.

In 1:25 scale that would be 2.4".

In 1:28 scale it would be 2.14".

So to widen a scale 60"-wide body from 1:28 scale to 1:25 scale, you'd have to add a little more than 1/4 inch.

BUT, you're not just adding it to the ends...you're stretching the curves and shapes equally all along their surfaces if you want accuracy.

I'm currently stretching a 1/28 scale Welly '55 Oldsmobile to 1/25, and it's slow going to get it to look right. It takes careful measuring, careful math (not hard, just careful) and thinking through each step.

 

[aurfalien]

As Bill Geary says, it's a lot of work if you want accuracy.

Consider: Assume a body width of 5 feet, or 60 inches.

In 1:25 scale that would be 2.4".

In 1:28 scale it would be 2.14".

So to widen a scale 60"-wide body from 1:28 scale to 1:25 scale, you'd have to add a little more than 1/4 inch.

BUT, you're not just adding it to the ends...you're stretching the curves and shapes equally all along their surfaces if you want accuracy.

I'm currently stretching a 1/28 scale Welly '55 Oldsmobile to 1/25, and it's slow going to get it to look right. It takes careful measuring, careful math (not hard, just careful) and thinking through each step.

 

I had a feeling you'd have done/be doing this.

I can see myself doing this, not yet though

Thanks to all for the feedback.

[aurfalien]

Man, that's an AWFUL lot of work to go through! I can tell you from having to "stretch" parts to suit a larger body, you might run into problems with symmetry, and since you're not practiced at this sort of thing, might it be better to modify an existing car (something similar) in that scale?

Yep, looks like I may have found a decent 1/24 Ferrari 712P body.  Although I wonder, you know those really old Mattel things that let you duplicate a part using some plastic sheets?

What if you were to layer sheets over atop one another until the proper growth is achieved?  Could be interesting.

Basically using the thickness of subsequent plastic sheets to add more and more scale.  Could be cool.

[Ace-Garageguy]

The Ferrari 712 CanAm car is fairly slab-sided and devoid of compound curves, and looks to me like it would be quite straightforward to stretch it a little. Do a scale 3-view drawing of the chassis you want to use, in the scale you want to use, showing its wheelbase and track width (show the locations of the ODs of the tires exactly) and sketch in the actual shapes of your existing body, with the correct existing dimensions. You'll find you can actually trace around them if you think it through and work carefully.

That will let you know how much meat you're going to have to splice in to get the scale-up right at the ends of the major sections of the car, and then you can concentrate on adjusting the curves to get a smooth flow.

Edited April 18, 2016 by Ace-Garageguy

[dshue76]

Yep, looks like I may have found a decent 1/24 Ferrari 712P body.  Although I wonder, you know those really old Mattel things that let you duplicate a part using some plastic sheets?

What if you were to layer sheets over atop one another until the proper growth is achieved?  Could be interesting.

Basically using the thickness of subsequent plastic sheets to add more and more scale.  Could be cool.

That wouldn't work. It would only make a fat version in the same scale. For instance it would not change wheel base. All growth in this are between the trailing edge of the front wheel well and leading edge of the rear wheel well would occur inside of the wheel openings causing them to get smaller. But center to center of wheel wells wouldn't change. You can't just think in terms of over all width and length.  You have to remember to increase size proportionally in all areas, horizontally between body lines and each individual body panel needs re sized. Take for instance a front fender, it would need to be increased in length in three areas minimum, in front of the wheel well, behind the wheel well and in the center of the wheel well, afterwards the wheel opening would need re shaped. then it would need to be made taller  in at least two places, in the middle of the wheel well and above the wheel well, if there are multiple horizontal body lines then it has to be increased in height between each. Afterwards the outside needs re shaped. Then the top surface of the fender needs widened.

Very time consuming.

Edited April 18, 2016 by dshue76

[Ace-Garageguy]

Something I've run into on doing the Welly up-scale is that it's not particularly accurate anyway, and some dimensions don't even need to be changed to get accurate 1/25 dimensions.

As we're all aware, kit and diecast makers frequently oops on their measuring and scaling, especially these days. Just something else to take into consideration.

It's interesting you've brought this up, as I saw several very interesting 1/28 scale plastic racing cars on ebay that i thought about buying for just such a project, but dismissed the idea on the grounds that I probably would just add them to the to-do pile, and not even start on them for years. Seemed better to let someone who might actually build them have a shot.