1:12 1932 Cadillac V-16 frame and engine

[Roger Zimmermann]

In parallel to the shock absorbers, I continued with the RTV product. All white walls are now done and, finally, I succeeded to have a decent pair of negative tire molds. Technically, I could directly cast the definitive tires with those molds, but it's too dangerous. If one of the negative mold is damaged, I can redo the whole scenario. At $55.00 for one kilo of the white RTV , I don't take the chance. Therefore, I will continue with my "regular" process.

[Roger Zimmermann]

There is nothing now to report about the tires because in between I began something else: the front suspension. The shop manual is stating that the V-16 models have 10 leaves in the front; I did 10 leaves for each spring. As I could not buy spring steel the exact width I wanted, I had to make the material a bit narrower; I did that work in the room where my cars and parts are stored. After drilling the holes for the central bolt (this bold is used to assemble all the leaves and to locate the axle on the springs), I installed the springs and axle on the frame. I discovered an error (this is not the first one nor the last one!) at the clips attaching the front axle: they are too short. I can hardly install some nuts, but this error is not that bad: with all the leaves, when I put a weight of 0.7 kg over the front axle, the springs are flexing about 1 mm! In the real life, a weight over more than 2000 pound would lower the front end by 1/2". Sure, those cars were not as comfortable as recent ones, but my springs are definitively too stiff, therefore I will remove some leaves until I'm satisfied.

[MODEL A MODEL]

[MODEL A MODEL]

Beautiful work. Very tight eyelets!

Your models are always filled with the eye-catching details!

A modeler's modeler!

[Roger Zimmermann]

Thanks Don! Indeed, the eyelets are rather tight: inside diameter 2.4mm (a tad under 0.1"). The material is stainless steel; I don't know if it's thermal treated; I tried one eyelet "as is" and another one after heating the tip of the leave. I have the impression that is was a tad easier.

[Roger Zimmermann]

As the negative molds were successfully done, I could cast the material into the recess to get the half positive molds. Right now, I don't know if this further step will be OK as many factors could lead to a disaster: the material can be uncured (it can happen), stick to the mold or air bubbles. I'm waiting another 24 hours to attempt the separation.
People here already know the whole process; as I'm publishing this construction into the Cadillac LaSalle forum, members there are seeing it for the first time.

[Roger Zimmermann]

SUCCESS! This morning, I separated the positive molds from the negative ones. At first, it was difficult to get the edges being separated; once I got that, the rest was easy. No bubble, all the material is well cured.
The next step: doing the definitive negative molds with a product like polyester. The product I used to do the negative molds was no more available at the store I'm going; a different product is no offered. Will it be so good as the previous one? There is a fundamental difference: the old product got cured with the addition of 3% hardener. This product is used by mixing tow parts from one element to one part of another one. Certainly easier to mix with the right proportion, but how are the characteristics of the cured product? I will have to make a test with a very small quantity.

[Roger Zimmermann]

After having a too stiff front suspension, it was logical that the rear one would follow. This time, I did only 3 leaves per side and, indeed, the suspension is rather soft. However, the rear springs are much longer than the front ones! According to the specifications, there were 9 leaves at the rear; I will add some later.
As you can maybe see, the rear suspension is very unstable with shackles at the front and at the rear: the drive tube is the element which locate the rear axle longitudinally. As you can understand, some more work is needed to have a working suspension...
I will soon do a test with the new resin : I just read that it's dry to the touch after two days and completely cured after fifteen days!

[markus68]

The rims, the frame: i am impresssed. Markus

[Roger Zimmermann]

Thanks Markus!

[Roger Zimmermann]

Yesterday, I did a test with the new product by mixing two parts from the base with one part of the harder. Not too much: 6 grams! Just to see if this product will have the expected properties for the half molds. This morning, the mix is almost tack-free. One of the big advantages compared to the polyester resin : NO SMELL!

[Roger Zimmermann]

As I wanted to have a functioning rear suspension, I did the torque tube. Its length is critical because the wheelbase is managed by that tube. That element is not yet ready: I have to add the bracket for the strut rods. Without those struts, the rear axle is unstable and, in real life, the differential carrier could be bent by driving on a rough road.
I will also have to modify the "shoes" for the rear axle; I did its top surface parallel to the pinion; it must be at an angle to match the transmission's end without binding.

[MODEL A MODEL]

Hello Roger!

Wow!

That top photo you've posted! That should be the center spread fold-out of some modeling magazine! -it really inspires, and your approach to modeling is so simple and effective.

Again, you are quite the teacher! Thank you!

-Don

[Roger Zimmermann]

Thanks for the flowers! However, if that picture is to be used as you are describing, the light should be better: the front end is too dark.
Well, I don't have the feeling to be a teacher; its also not my goal. What I try to show is that with a minimum of equipment, a realistic model can be created. In that aspect, in the Cadillac forum, there is a topic about reproducing parts scale 1:1 with the 3D printer. When I'm reading all what is needed to achieve that and at which cost, I do assume that for scale modeling it's about the same...

[Roger Zimmermann]

With the addition of the struts, the torque tube is now complete. If you are looking at the picture, you'll see that the thread near the tube is much longer than the one towards the wheels. There is a reason for that. Which one?