Neanderpundit

This is where the complexity of the geometry starts to bite

If you aren’t cutting a square, which almost nobody does, then you have to make sure the part you’re cutting is capable of being cut. This shape, no matter how simple, cannot be cut.

You cannot cut a sharp inside corner using a round tool, The only thing you can cut is a round inside corner, and cut the sharp corner, if it is necessary, in a separate operation.

Look at the slide opening in my PPX.

There are NO sharp inside corners. Even the breechface has rounded corners, the barrel has simply been designed to mate with that. This means that no consecutive operations are required to make it square. That means when you put this chunk of metal into a machine, it comes out complete, and is ready for finishing and assembly. The 1911 slide, by comparison, needs about 30 operations after it is initially machined.

More manufacturing yapping.

Locus of points is a way of showing geometric data, among other things. For instance:

What is the locus of points of all the points 5 inches from 0,0? That would be a circle, 10″ in diameter. What is the locus of points of the center of a 4″ dia circle travelling around a 10″ square, remaining in contact with the square at all times?

Here’s an illustration. Click to embiggenate.

You can see the original black square. On the right, the blue represents the circle, the green is the locus of points of that center. On the left in pink you can see how the circle drags that center along as it moves, and the orange shows how it brings the center with it as it rolls around the corner.

all machining depends on understanding this. A lot of people never get it, but to many it is intuitive. Most cutting tools are circular, and knowing what they have to cut (In this place, the black square) and what their radius is, it is a simple matter to program a path (The green line) that is the path that must be taken to machine the part that size and shape.

it gets a lot more complex than this, but you have to understand this first. This- and the sort of relative processes that take place in robots, are what my very smart cousin call “N Dimension Geometers” The explanation he gave went mostly in every direction but my skull but I gather that it means the size and shape of things in relation to their location and how they are represented in 1, 2, 3, 4,… n dimensions. I just know there are simple rules to follow and so long as you do, you can bend all this equipment to your will. If you don’t get it, be a barber. There’s no shame in not understanding this, it’s not easy.

I did recon on an upcoming robot installation, in a company where we have already installed dozens of robots. One of the cells there is one of my first start-to-finish systems- I designed it, specified all the pieces, wrote all the code, tested the cycle time over all, installed and implemented it. it began to run in 1996 and has been pounding parts out ever since, 24 hours a day, 7 days a week, weekends and holidays and yes, even Christmas. it makes a timing gear for diesels- big diesels have gears and not chains, since when lubed properly the gears don’t show any appreciable wear, and last, usually, longer than the engine. These gears go in N10 and N13 engines, if I recall correctly, and most International straight trucks you see out there have them.

The robot and the machines are still running fine, making parts in spec, no issues. I have no idea how many millions of parts it’s made. I know it will keep doing so for many years to come because the system has a built in high resistence to neglect. Grease and oil are delivered automatically to the machines, and they stop running when the oilers are dry.

A lot of those systems exist that I created or helped create. They run so robustly they will be going long after I’m gone. I’m always happy to visit them because it is a reminder that sometimes your actions are larger than they appear.

Here’s another of my babies that will most likely still be making stuff long after I’m gone