With Wings As Eagles: Craig P. Steffen's Blog

the platonic ideal

2008 July 28 08:30

My vauge memory of undergraduate philsophy class was that there's the idea of a "platonic ideal" of something; that unattainable perfect example, of, say, a table. I've been similarly facinated with the a similar idea related to production of something. When you build a prototype, there are almost always things that need to be fixed for the first production run. And often when something is being produced or manufactured, there are small corrections as the manufacturing process gets smoothed out. So in manufactured things, the "real" version is the one far enough into the production run that everything is being produced consistently.

In building low or single instances of something, there's an interesting dichotomy that's similar to the Platonic ideal idea. You often build an engineering prototype of something to get the functional aspects correct before building the real thing. Once you get the prototype laid down, then you buid the real item. The dichotomy is that the real item is one layer farther removed from the ideal because it's a copy, but often the engineering prototype was built in such a way that it cannot substitute for the final item.

I've fixed enough trivial stuff in my beetle that it's time to get down to brass tacks and actually fix the engine. I had fun working on the brake warning light, but now I have to face the fact that something is very wrong in the right side cylinder head in the engine and I need to replace it before I drive the car cross-country. To do that, I need to remove the engine. Since I've never done this before, I'm being overly paranoid about preparations. Different people use different strategies for getting the engine out of the car, and I'm not really sure how delicate the bottom is, and I'm concerned about what could happen to the bottom of the engine if it's jacked wrong.

So I'm bulding a wooden pad that will sit on the jack and support the engine, hopefully more gently than the steel jack saddle would.

Here's the bottom of the engine.

In the middle is the oil sump plate, which is pressed out of sheet steel and I don't really consider a structural part. And the edges and the center of the engine block stick down a bit, but in the middle there nice flat areas that I think are reasonable to use as support.

So first I made a cardboard template to get the dimensions about right:

The cardboard template

is what got me thinking about the platonic prototyping thing. When I was thinking about making the pad, and designing it, the carboard piece was what I was thinking about and using. However, it can't be used for the final product.

Here's the partially complete final item...

The good news is that it fits on the bottom of the engine just fine:

However, the whole idea of this piece is to lower it onto the engine cart, so it has to fit through the center of the cart...which it doesn't quite.

So I'll have to trim the sides. Not bad, though, for something that was an idea in my head 24 hours ago.