Locus of Points.
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.
Are you and P. coming down to the gun show? We’re both in Indy this weekend.
Me, at least.
This kind of reminds me of finding the line through a curve. We had a slalom event one weekend a year at the college I went to. I took a 1976 LTD 4 door through it without much effort. Earned a place driving on a guy’s go-kart enduro team because of that.
Like you said, it comes natural to some, others have to be taught, and others should do something else.
I really have enjoyed this series of manufacturing topics. I’ve seen your thought processes through your posts, but now I can understand a bit more how you are “trained” to reason things out. I always find it interesting how one passion or talent can bleed over into the rest of our lives.
Thanks, and take care!
Directly related: Finding the most efficient path for your lawnmower to cut the most, smoothly, with the least effort and overlap of previous cuts.
At least it gives one something to think about, other than “I hate mowing!”
Jim
Sunk New Dawn
Galveston, TX
There is always something to think about while mowing. I just need to work on the things I can control.
Like the discussion of milling a square.
No it’s not. And this is ‘simple’ shape… When you’re doing convoluted shapes (e.g. acft parts), it gets REALLY complicated and takes some computing power to sort out the ‘exact’ paths required.
It does indeed come naturally to some, but not to all. A good friend started in machining when we were 18 (198cough), on manual lathes. Worked his way up to mills, took a couple of CAD classes, and managed to teach himself the art of programming CNC mills. He’s made a good bit of money at it–and earned every damned dollar of it, IMHO.
Not everyone has the touch. I can write a small CNC program, or could 15 years ago (probably not now, I’ve been away & am doing different things), but his programs & the results were just that–art.