MTFCA Forum

Professor Fate wrote: ↑

Tue Aug 22, 2023 6:19 am

Maybe someone will 3D print an update on the plastic fan that allows for indexed accurate placement on the pulley hub.

Wayne Sheldon wrote: ↑

Tue Aug 22, 2023 7:15 pm

At the risk of stepping on my tongue as I put my foot in my mouth? I just really don't get this whole "plastic fan" business.
In the first place, any obviously anachronistic alteration of an antique vehicle, to me, lessens the value, and the effect, and in turn my interest, in said vehicle. Whether in a photo or a car show, an open hood showing modern alternators, modern oil filters, and modern plastic fans, along with silly accent color painting, freakish color wiring etc etc etc, ruins the historic effect and feeling for the vehicle. Not only do such things ruin the look, they ruin the feel, they do not in any significant way improve the ride or reliability to the driving of said vehicle.
Secondly, at the speeds a model T (or almost any prewar era car?) engine turns, good steel blade fans that have not been somehow damaged by mishandling, collision, rust corrosion, or extensive vibration, have been fine for three quarters of a century or more! Yes, they do need to be carefully inspected during restoration, and occasionally during routine service to avoid a nasty future failure. However, if they look good? They should be good for another quarter century or more.

How many people (here? anywhere?) actually know what the word "plastic" means? What is its origin? In a "universal" sense, "physics" is the scientific study of matter and energy in the universe that surrounds us. Most people "know" of the three stages of matter; "gaseous", "liquid", and "solid". However, there are a few others. Two that we hear about more than most people realize, are "plasma" (an extremely active supper-heated gas), and "plastic". "Plastic" is a middle-ground. It lies between when a material mass is a solid or a liquid. Different materials have differing "plastic" stages (that condition where it is neither truly solid or really liquid). Some materials have very narrow ranges of temperature between liquid and solid (ever try to weld brass?). Other materials like steel have wider plastic stages (and are much easier to weld!). Some materials have almost no plastic stage. Wood for instance does not have even a liquid stage, let alone a plastic stage. It goes almost straight from solid to gas (or in the absence of oxygen, dust). Sugar can be a solid or a liquid, however the molecular structure falls apart if heated too much, so there is no "gaseous" state.

"Plastics" in the modern sense, are artificial materials that have a not quite solidness about them. They are in our normal environment, never quite solid. That means that they continue to flow, no matter how slowly, well after they have been manufactured into some product. Most plastics of the past three quarters of a century also literally evaporate. Again, very slowly. Heat, chemical contaminants, and UV or other external energies can speed up the material flow and evaporation of plastic materials.
Plasticity, flexibility, and bending, while similar, are not exactly the same things. Plastics tend to be more flexible, while solids may be bendable. Defining that whole thing would be quite a dissertation.

It seems to me that a plastic fan on a model T is a short-term fix for a long term problem.
I think I will stick with the original fans.

Mark Nunn wrote: ↑

Tue Aug 22, 2023 8:44 am

Professor Fate wrote: ↑

Tue Aug 22, 2023 6:19 am

Maybe someone will 3D print an update on the plastic fan that allows for indexed accurate placement on the pulley hub.

Mark N. wrote....
I have used 3-D printed plastics to build prototypes for over 25 years. I would NEVER trust a 3-D printed fan behind my new Brassworks radiator.